Ultrasound Guidance – Selected Indications

Number: 0952

Policy

Aetna considers ultrasound (US) guidance medically necessary for the following procedures (not an all-inclusive list):

Adductor canal nerve block
Arterial line placement
Axillary brachial plexus nerve block
Baker's cyst, after failure of unguided procedure
Breast mass biopsy (see CPB 0269 - Breast Biopsy Procedures)
Carpal tunnel injection
Central venous access (internal jugular, femoral)
De Quervain tendinopathy, after failure of unguided procedure
Elbow joint injection or aspiration, after failure of unguided procedure
Embryo transfer (see CPB 0327 - Infertility)
Endovenous laser ablation of the saphenous vein (ELAS) (see CPB 0050 - Varicose Veins)
Fascia iliaca block for the management of post-operative pain following hip and knee surgeries
Femoral nerve block for post-operative knee pain
Hepatic mass biopsy
Hip joint injection or aspiration
Iliohypogastric nerve block
Ilioinguinal nerve block
Intercostobrachial nerve block
Interscalene nerve block
Intraabdominal or intrapelvic mass biopsy
Intrathecal drug delivery
Lateral femoral cutaneous nerve block for meralgia paresthetica (lateral femoral cutaneous nerve entrapment) (see CPB 0863 - Nerve Blocks)
Lumbar puncture (see CPB 0628 - Spinal Ultrasound)
Metacarpophalangeal joint injection or aspiration
Metatarsophalangeal joint injection or aspiration
Nephrocutaneous access
Pancreatic mass biopsy
Pectoralis nerve block (PEC 1 and PEC 2) for the management of post-operative pain following mastectomy
Piriformis muscle injection
Placement of vena caval filter (see CPB 0382 - Intravascular Ultrasound)
Placement of intracoronary endoluminal devices (see CPB 0382 - Intravascular Ultrasound)
Popliteal nerve block
Posterior glenohumeral (GH) joint injection or aspiration, after failure of unguided procedure
Pulmonary or thoracic mass biopsy
Prostate biopsy for prosate nodule or elevated PSA (see CPB 0001 - Transrectal Ultrasound)
Quadratus lumborum nerve block for post-operative pain control after abdominal surgery
Radiofrequency endovenous occlusion (VNUS) (see CPB 0050 - Varicose Veins)
Scapular thoracic bursitis injection
Sciatic nerve block
Serratus plane block for the management of post-operative pain following breast surgery or thoracotomy
Subacromial bursal injection or aspiration, after failure of unguided procedure
Subtalar joint injection or aspiration
Supraclavicular nerve block for post-operative pain control
Tibiotalar joint injection or aspiration, after failure of unguided procedure
Thyroid nodule biopsy
Transverse abdominis plane (TAP)-block for the management of post-operative pain following abdominal surgery
Wrist (radiocarpal) joint injection or aspiration, after failure of unguided procedure.

Aetna considers US guidance of no proven benefit for the following procedures (not an all-inclusive list):

Acromioclavicular joint
Botulinum toxin injection for the treatment of migraine or cervical dystonia
Costochondral joint
Dorsal scapular nerve block
Endovascular treatment of subclavian artery disease (see CPB 0382 - Intravascular Ultrasound)
Epidural injections, including the transforaminal approach (see CPB 0016 - Back Pain - Invasive Procedures)
Erector spinae plane (ESP) block for the management of post-operative pain (see CPB 0863 - Nerve Blocks)
Facet joint injections (see CPB 0016 - Back Pain - Invasive Procedures)
Gluteal nerve injection
Hydrodissection of infrapatellar saphenous nerve
Iliopsoas bursa injection
Iliopsoas tendon sheath injection
Iliotibial band hydrodissection
Infiltration between the popliteal artery and capsule of the knee (IPACK) block for pain control following anterior cruciate ligament (ACL) repair
Intercostal nerve block
Knee joint (except in morbidly obese individuals (BMI > 40))
Lavage of the shoulder joint
Ligament sheath injections
Lumbar plexus block with hydrodissection
Medial calcaneal nerve sheath injection
Median nerve block
Needle placement during aortography
Occipital nerve block (see CPB 0863 - Nerve Blocks)
Plantar fasciitis injections
Psoas tendon injection
Sacroiliac joint injection (see CPB 0016 - Back Pain - Invasive Procedures)
Sclerotherapy for varicose veins (see CPB 0050 - Varicose Veins)
Superficial radiation treatment of skin cancer
Superior cluneal nerve injections
Tendon injections (other than those listed as medically necessary above)
Trigger finger injection/trigger finger release with or without hydrodissection
Trigger point injections (see CPB 0016 - Back Pain - Invasive Procedures)
Trochanteric bursa injections
Viscosupplement injections (see CPB 0179 - Viscosupplementation).

Background

In the past 10 years, ultrasound (US) has become increasingly popular to image both peripheral musculoskeletal and axial structures. Presently, US is often used to guide interventions such as aspiration, hydrodissection, tenotomy, as well as diagnostic or therapeutic injections (e.g., epidural, facet joint, intra-articular, sacroiliac joint, subtalar joint, trigger point and viscosupplement injections). This clinical policy bulletin describes some of the medically necessary as well as experimental/investigational indications associated with the use of US guidance.

Ultrasound Guidance: Medically Necessary Indications

Adductor Canal Nerve Block

An UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019a) states that "The saphenous nerve is the terminal sensory branch of the femoral nerve. The saphenous nerve block is useful for ambulatory surgeries of the superficial, medial lower leg and provides analgesia of the medial ankle and foot. It can be blocked at the level of the tibial tuberosity below the knee, above the knee using the adductor canal block, or at the ankle as part of an ankle block. Adductor canal block – The saphenous nerve is blocked at the level of the mid-thigh with the adductor canal block using ultrasound guidance … Ultrasound-guided adductor canal block – The ultrasound probe is placed perpendicular to the thigh at the midpoint between the anterior superior iliac spine and the base of the patella. The nerve is identified as it lies adjacent to the femoral artery. It is followed distally as it becomes more superficial, traveling with an arterial branch just deep to the sartorius muscle. Using an in-plane approach, after negative aspiration, 10 ml of local anesthetic (LA) is injected deep to the sartorius muscle, at the lateral border of the artery".

Axillary Brachial Plexus Nerve Block

Klaastad and co-workers (2009) noted that many of the reports concluded that US guidance may provide a higher success rate for brachial plexus blocks than guidance by nerve stimulator. However, the studies were not large enough to conclude that US will reduce the risk of nerve injury, local anesthetic toxicity or pneumothorax. Ultrasound may reveal anatomical variations of importance for performing brachial plexus blocks. For post-operative analgesia, 5 ml of ropivacaine 0.5 % has been sufficient for an US-guided interscalene block. For peri-operative anesthesia, as much as 42 ml of a local anesthetic mixture was calculated to be appropriate for an US-guided supraclavicular method. For the future, these investigators noticed that 3D- and 4D-US technology may facilitate visualizing the needle, the nerves and the local anesthetic distribution. Impedance measurements may be helpful for nerve blocks not guided by US. The authors concluded that the literature gave a sufficient basis to recommend the use of US for guidance of brachial plexus blocks.

Nadeau and associates (2013) reviewed the main US-guided approaches used for regional anesthesia of the upper limb. The anatomical configuration of the upper limb, with nerves often bundled around an artery, makes regional anesthesia of the arm both accessible and reliable. In-depth knowledge of upper limb anatomy is needed to match the blocked territory with the surgical area. The interscalene block is the approach most commonly used for shoulder surgery. Supra-clavicular, infra-clavicular, and axillary blocks are indicated for elbow and forearm surgery. Puncture techniques have evolved dramatically with US guidance. Instead of targeting the nerves directly, it is now recommended to look for diffusion areas. Typically, local anesthetics are deposited around vessels, often as a single injection. Phrenic nerve block can occur with the interscalene and supra-clavicular approaches. Ulnar nerve blockade is almost never achieved with the interscalene approach and not always present with a supra-clavicular block. If US guidance is used, the risk for pneumothorax with a supra-clavicular approach is reduced significantly. Nerve damage and vascular puncture are possible with all approaches. If an axillary approach is chosen, the consequences of vascular puncture can be minimized because this site is compressible. The authors concluded that upper limb regional anesthesia has gained in popularity because of its safety profile and effectiveness associated with US-guided techniques.

Xu and colleagues (2017) examined the safety and efficacy of bilateral axillary brachial plexus block under US-guidance or neurostimulator-guidance. From February 2012 to April 2014, a total of 120 patients undergoing bilateral hand/forearm surgery were anesthetized with bilateral axillary brachial plexus block. All patients were divided into 2 groups randomly using random number table: the US-guided group (group U, n = 60) and the neurostimulator-guided group (group N, n = 60). The block was performed with 0.5 % ropivacaine. Patients' age, sex and operation duration were recorded. Moreover, success rate, performance time, onset of sensor and motor block, performance pain, patient satisfaction degree and the incidence of related complications were also documented. Venous samples were collected at selected time-points and the total and the plasma concentrations of ropivacaine were analyzed with HPLC. The performance time, the onset of sensor block and the onset of motor block of group U were (8.2 ± 1.5), (14.2 ± 2.2)and (24.0 ± 3.5) mins, respectively, which were markedly shorter than those in group N ( (14.6 ± 3.9), (19.9 ± 3.8), (28.8 ± 4.2) mins, respectively), and the differences were statistically significant (t = 11.74, 10.09, 6.73, respectively, all p < 0.01). The performance pain score of group N was (25.5 ± 13.2), which was obviously more serious than group U (31.7 ± 11.2) and a significant statistical difference was detected (t = 2.856, p < 0.05). The patient satisfaction degree of group U was 95.0 %, which was significantly higher than group N (83.3 %) and a markedly statistical difference was detected (χ(2) = 4.227, p < 0.05); 50 mins after performance, the total plasma concentration of ropivacaine of group U was (1.76 ± 0.48 mg/L), which was significantly lower than group N (1.88 ± 0.53 mg/L) and a significant statistical difference was detected (t = 2.43, p < 0.05), while no significant differences were detected at the other time-points between 2 groups (p > 0.05). No analgesic was super-added and no other anesthesia methods were applied. No complications were detected peri-operatively. The authors concluded that the bilateral axillary brachial plexus block under US-guidance or neurostimulator-guidance were both safe and effective for bilateral hand/forearm surgery. However, the US-guided block may be more clinically beneficial because of its shorter performance time, rapid onset and higher patient satisfaction degree.

Li and associates (2020) stated that neurostimulator-guidance and US-guidance are 2 major methods that have been widely accepted and applied in axillary brachial plexus block. However, the differences between the effects of these 2 types of guidance still need to be further elucidated for clinical usage. This study included a total of 208 patients undergoing elective upper limb surgeries and receiving axillary brachial plexus block. The patients were randomly assigned to receive either US-guidance (group U, n = 112) or nerve stimulation (group N, n = 96). Pinprick test was performed for assessing the sensory blockades. The pain was evaluated by visual analog scale (VAS). Reactive oxygen species (ROS) levels were measured by dichloro-dihydro-fluorescein diacetate staining and serum levels of nitric oxide (NO), nitric oxide synthases (NOS), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein 1 (MCP1) were evaluated by ELISA. Results showed that US-guidance significantly enhanced the quality of the sensory blockade and reduced the VAS scores when compared with the neurostimulator-guidance. In addition, the production of ROS, NO, NOS, TNF-α, and MCP-1 were significantly alleviated by US-guidance. The authors concluded that US-guided brachial plexus block relieved pain during operation, provided higher success rates in the nerve block, caused less vascular damage and resulted in lower levels of inflammatory cytokines secretion when compared with neurostimulator-directed brachial plexus blockage.

Fascia Iliaca Block for the Management of Post-Operative Pain Following Hip and Knee Surgeries

In a meta-analysis, Wang et al (2017) compared the safety and efficiency between femoral nerve block (FNB) and fascia iliaca block (FIB) for post-operative pain control in patients undergoing total knee and hip arthroplasties. These investigators carried out a systematic search in Medline (1966 to 2017.05), PubMed (1966 to 2017.05), Embase (1980 to 2017.05), ScienceDirect (1985 to 2017.05) and the Cochrane Library. Inclusion criteria:

Participants: Only published articles enrolling adult participants that with a diagnosis of end-stage of osteoarthritis (OA) and prepared for unilateral total knee arthroplasty (TKA) or THA;
Interventions: The intervention group received FIB for post-operative pain management;
Comparisons: The control group received FNB for post-operative pain control;
Outcomes: VAS scores in different periods, opioids consumption, length of stay (LOS) and post-operative complications;
Study design: clinical RCTs were regarded as eligible in this study.

Cochrane Hand book for Systematic Reviews of Interventions was used for assessment of the included studies and risk of bias was shown. Fixed/random effect model was used according to the heterogeneity tested by I2 statistic. Sensitivity analysis was conducted and publication bias was assessed. Meta-analysis was performed using Stata 11.0 software. A total of 5 RCTs including 308 patients met the inclusion criteria. The present meta-analysis indicated that there were no significant differences between groups in terms of VAS score at 12 hours (SMD = -0.080, 95 % CI: -0.306 to 0.145, p = 0.485), 24 hours (SMD = 0.098, 95 % CI: -0.127 to 0.323, p = 0.393), and 48 hours (SMD = -0.001, 95 % CI: -0.227 to 0.225, p = 0.993). No significant differences were found regarding opioid consumption at 12 hours (SMD = 0.026, 95 % CI: -0.224 to 0.275, p = 0.840), 24 hours (SMD = 0.037, 95 % CI: -0.212 to 0.286, p = 0.771), and 48 hours (SMD = -0.016, 95 % CI: -0.265 to 0.233, p = 0.900). In addition, no significant increase of complications was identified between groups. The authors concluded that there was no significant differences of VAS scores at 12 to 48 hour and opioids consumption at 12 to 48 hour between 2 groups following total joint arthroplasty. No increased risk of nausea, vomiting and pruritus was observed in both groups. These investigators stated that FNB provided equal post-operative pain control compared with FIB following total joint arthroplasty. Both of them could reduce the consumption of opioids without severe adverse effects.

Gao et al (2019) stated that optimal pain management after total hip arthroplasty (THA) remains controversial. These researchers carried out a meta-analysis from randomized controlled trials (RCTs) to examine the safety and efficacy of fascia iliaca compartment block (FICB) in THA. They conducted electronic searches of PubMed, Medline, Cochrane library, and Web of Science before February 2019. These researchers collected RCTs to compare FICB and placebo for pain control after THA. The outcome measurements consisted of pain score, opioid consumption, length of hospitalization and post-operative complications. All data analyses were conducted using STATA 13.0. Cochrane Collaboration's tool was adopted to assess the risk of bias. A total of 7 RCTs met the inclusion criteria with 165 patients in the FICB groups, and 160 patients in the placebo groups. The present meta-analysis indicated that there were significant differences between the groups in terms of pain score at post-operative 12 hours (weighed mean difference [WMD] = -0.285, 95 % confidence interval [CI]: -0.460 to -0.109, p = 0.002) and 24 hours (WMD = -0.391, 95 % CI: -0.723 to -0.059, p = 0.021). FICB was associated with significant superior in opioid consumption at post-operative 12 hours (WMD = -5.394, 95% CI: -8.772 to -2.016, p = 0.002) and 24 hours (WMD = -6.376, 95 % CI: -10.737 to -2.016, p = 0.004) compared with placebo. No significant difference was identified regarding length of hospitalization (WMD = 0.112, 95 % CI: -0.125 to 0.350, p = 0.354). The authors concluded that fascia iliaca compartment block was effective for pain relief during the early post-operative period after THA. Meanwhile, it reduced the cumulative morphine consumption and the risk of opioid-related adverse effects.

In a meta-analysis, Cai et al (2019) examined the effect of FICB on pain control and morphine consumption in patients with THA. These investigators searched databases (PubMed, Embase, Cochrane Library) for eligible randomized controlled trials (RCTs) published prior to September 12, 2018. They only included THA patients who received FICB versus placebo for pain control. Risk ratios (RRs), standard MD (SMD) and 95 % CI were determined. Stata 12.0 was used for the meta-analysis. A total of 326 THA patients from 7 RCTs were subjected to meta-analysis. Overall, FICB was associated with lower visual analog scale (VAS) scores at 1 to 8 hours and 12 hours compared with placebo (p < 0.05). However, there was no significant difference between VAS at 24 hours (SMD = -0.56, 9 5% CI: -1.42 to 0.31, p = 0.206) and 48 hours after THA (SMD = -0.82, 95 % CI: -2.07 to 0.44, p = 0.204). Compared with the control group, FICB significantly decreased the occurrence of nausea (RR = 0.41, 95 % CI: 0.25 to 0.69, p = 0.010; I2 = 0.0 %). There was no significant difference in the risk of falls between the FICB and control groups (p > 0.05). The authors concluded that FICB had a beneficial role in reducing pain intensity and morphine consumption after THA. Moreover, FICB had morphine-sparing effects when compared with a control group.

Diakomi et al (2020) stated that chronic post-surgical pain (CPSP), i.e., pain persisting greater than 3 months, may appear after any type of surgery. There is a paucity of literature addressing CPSP development after hip fracture repair and the impact of any analgesic intervention on the development of CPSP in patients after hip fracture surgery. In a prospective. randomized study, these researchers examined the impact of ultrasound-guided FICB (USG-FICB) on the development of CPSP after hip fracture repair. A total of 182 patients scheduled for hip fracture surgery were included in this trial. Patients were randomized to receive a USG-FICB (FICB group) or a sham saline injection (sham FICB group), 20 mins before positioning for spinal anesthesia. The hip-related characteristic pain intensity (CPI) at 3-months post-surgery was the primary outcome measure. Presence and severity of hip-related pain at 3- and 6-months post-surgery, NRS scores at 6, 24, 36, 48 post-operative hours, total 24-hour tramadol patient-controlled analgesia (PCA) administration and timing of the first tramadol dose, were documented as well. FICB group presented with lower CPI scores 3-months post-operatively (p < 0.01), as well as lower percentage of patients with high-grade CPSP, 3 and 6 months post-operatively (p < 0.001). FICB group also showed significantly lower NRS scores in all instances, lower total 24-hour tramadol consumption and higher mean time to first tramadol dose (p < 0.05). The overall sample of 182 patients reported a considerably high incidence of hip-related CPSP (60 % at 3 months, 45 % at 6 months). The authors concluded that USG-FICB in the peri-operative setting may reduce the incidence, intensity and severity of CPSP at 3 and 6 months after hip fracture surgery, providing safe and effective post-operative analgesia.

Furthermore, an UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2020) states that "Peripheral nerve blocks of the lower extremity are used for operative anesthesia and/or postoperative analgesia for a variety of lower extremity surgeries … Femoral nerve block is used to provide anesthesia or postoperative analgesia for surgery of the anterior thigh and knee (e.g., anterior cruciate ligament repair, patella surgery, quadriceps tendon repair) … The fascia iliaca block is an alternative to the femoral nerve block and may more reliably block the lateral femoral cutaneous nerve than the femoral block. It blocks the sensory innervation of the lateral thigh. This block does not depend on deposition of local anesthetic (LA) near an individual nerve; instead, it works by spread of the LA in a fascial plane. Therefore, this block is not performed with nerve stimulation. It can be done using ultrasound guidance or with an anatomic approach".

Femoral Nerve Block for Post-Operative Knee Pain

An UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019a) states that "Femoral nerve block is used to provide anesthesia or postoperative analgesia for surgery of the anterior thigh and knee (e.g., anterior cruciate ligament repair, patella surgery, quadriceps tendon repair). Traditionally, this block was also referred to as the "3-in-1" block, wherein high volume of local anesthetic (LA) can block the femoral, lateral femoral cutaneous, and obturator nerves. This concept was based on the purported existence of a supra-inguinal fluid compartment between the femoral nerve sheath and the lumbar plexus, capable of allowing spread of LA proximally to the lumbar plexus with a single injection at the femoral nerve in the inguinal region. However, a human cadaver study has shown that a fluid compartment between the femoral nerve sheath and the lumbar plexus does not exist, and several studies have shown that a femoral block does not reliably block the obturator nerve, the lateral femoral cutaneous nerve, or the lumbar plexus. Since only the femoral nerve is reliably blocked by this technique, we usually now refer to it as the femoral nerve block. Ultrasound-guided femoral block – The ultrasound transducer is placed in the inguinal crease to locate the hyperechoic femoral nerve, which can be visualized lateral to the hypoechoic pulsatile common femoral artery, superficial to the iliopsoas muscle group, and deep to the fascia lata and fascia iliaca. An in-plane or out-of-plane approach can be used. The needle is inserted and the tip placed adjacent to the nerve. After negative aspiration, 20 to 40 mL of LA is injected in 5 mL increments, with gentle aspiration between injections. LA should be seen spreading above, below, or circumferentially around the nerve".

Ilioinguinal Nerve Block

Wang et al (2016) stated that ultrasound (US)-guided ilioinguinal / iliohypogastric (II/IH) nerve and TAP blocks have been increasingly utilized in patients for peri-operative analgesia. These researchers conducted a meta-analysis to examine the clinical efficacy of US-guided II/IH nerve or TAP blocks for peri-operative analgesia in patients undergoing open inguinal surgery. A systematic search was conducted of 7 databases from the inception to March 5, 2015. Randomized controlled trials (RCTs) comparing the clinical efficacy of US-guided versus landmark-based techniques to perform II/IH nerve and TAP blocks in patients with open inguinal surgery were included. They constructed random effects models to pool the standardized mean difference (SMD) for continuous outcomes and the odds ratio (OR) for dichotomized outcomes. US-guided II/IH nerve or TAP blocks were associated with a reduced use of intra-operative additional analgesia and a significant reduction of pain scores during day-stay. The use of rescue drugs was also significantly lower in the US-guided group. The authors concluded that the use of US-guidance to perform an II/IH nerve or a TAP block was associated with improved peri-operative analgesia in patients following open inguinal surgery compared to landmark-based methods.

In a prospective, randomized clinical trial, Faiz et al (2019) compared the efficacy of ilioinguinal / iliohypogastric (IINB) nerve block to TAP block in controlling incisional pain after open inguinal hernia repair. This trial included 90 patients who received either IINB (n = 45) or TAP block (n = 45) using 0.2 % bupivacaine 15 ml under US guidance based on a random assignment in the post-anesthesia care unit (PACU) after having an open repair of inguinal hernia. Numeric Rating Scale (NRS) scores were recorded immediately following, 4, 8, 12, and 24 hours after completion of the block; NRS scores at rest and during movement were recorded 24, 36, and 48 hours after surgery. Analgesic satisfaction level was also evaluated by a Likert-based patient questionnaire. NRS scores were lower in the IINB group compared to the TAP block group both at rest and during movement. The difference in dynamic pain scores was statistically significant (p = 0.017). In addition, analgesic satisfaction was significantly greater in the IINB group than the TAP block group (mean score 2.43 versus 1.84, p = 0.001). Post-operative opioid requirements did not differ between the 2 groups. The authors concluded that the findings of this study demonstrated that compared to TAP block, local blockade of ilioinguinal and iliohypogastric nerves provided better pain control after open repair of inguinal hernia when both blocks were administered under US guidance. Greater satisfaction scores also reflected superior analgesia in patients receiving IINB.

Bhatia et al (2019) noted that analgesic efficacy of US-guided TAP block, administered a little more medially, just close to the origin of the transverse abdominis muscle has not yet been examined in patients undergoing unilateral inguinal hernia repair. These researchers hypothesized that medial TAP block would provide comparable post-operative analgesia to ilioinguinal-iliohypogastric nerve block in inguinal hernia repair patients. This prospective, randomized trial was conducted in 50 ASA I and II male patients greater than or equal to 18 years of age. Patients were randomized into 2 groups to receive either pre-incisional ipsilateral US-guided ilioinguinal-iliohypogastric nerve block or medial TAP block, with 0.3 ml/kg of 0.25 % bupivacaine. The primary objective was post-operative 24-hour analgesic consumption and secondary outcomes included pain scores, time to first request for rescue analgesic and side effects, if any, in the post-operative period. There was no significant difference in the total post-operative analgesic consumption [group I: 66.04 mg; group II: 68.33 mg (p value 0.908)]. Time to first request for rescue analgesic was delayed, though statistically non-significant (p value 0.326), following medial TAP block, with excellent pain relief observed in 58.3 % patients as opposed to 45.8 % patients in ilioinguinal-iliohypogastric nerve block group. The authors concluded that medial TAP block being a novel, simple and easily performed procedure can serve as an useful alternative to ilioinguinal-iliohypogastric nerve block for providing post-operative pain relief in inguinal hernia repair patients.

Samerchua et al (2020) stated that ilioinguinal/iliohypogastric nerve block is commonly performed to control post-herniotomy pain. The posterior quadratus lumborum block has been recently described as an effective analgesic technique for pediatric low abdominal surgery. No data were found regarding the use of posterior quadratus lumborum block in comparison with the traditional ilioinguinal/iliohypogastric nerve block in pediatric inguinal surgery. In a randomized, assessor-blinded study, these researchers compared post-operative analgesic effects between US-guided posterior quadratus lumborum block and ilioinguinal/iliohypogastric nerve block in pediatric inguinal herniotomy. 1- to 7-year-old children scheduled for unilateral open herniotomy were randomly assigned to receive either US-guided posterior quadratus lumborum block with 0.25 % bupivacaine 0.5 ml/kg or US-guided ilioinguinal/iliohypogastric nerve block with 0.25 % bupivacaine 0.2 ml/kg after induction of general anesthesia. The primary outcome was the proportion of patients who received post-operative oral acetaminophen. The required fentanyl in the recovery room, 24-hour acetaminophen consumption, success rate of regional blocks, block performance data, block-related complications, post-operative pain intensity, and parental satisfaction were assessed. This study included 40 patients after excluding 4 cases who were ineligible. The number of patients who required post-operative oral acetaminophen was significantly lower in the posterior quadratus lumborum block group (15.8 % versus 52.6 %; odds ratio [OR]: 5.9; 95 % confidence interval [CI]: 1.3 to 27.3; p = 0.022). The pain scores at 30 mins, 1, 2, 6, 12, and 24 hours were similar between groups. There was no evidence of between-group differences in block performance time, the number of needle passes, block-related complications, and parental satisfaction. The authors concluded that the posterior quadratus lumborum block with 0.25 % bupivacaine 0.5 ml/kg provided better pain control than the ilioinguinal/iliohypogastric nerve block with 0.25 % bupivacaine 0.2 ml/kg after open herniotomy in children. The US guidance technique for the posterior quadratus lumborum block was safe and as simple as the US-guided ilioinguinal/iliohypogastric nerve block for pediatric patients.

Intercostobrachial Nerve Block

Satapathy and Coventry (2011) noted that the axillary approach to brachial plexus blockade provides satisfactory anesthesia for elbow, forearm, and hand surgery and also provides reliable cutaneous anesthesia of the inner upper arm including the medial cutaneous nerve of arm and intercostobrachial nerve, areas often missed with other approaches. In addition, the axillary approach remains the safest of the 4 main options, as it does not risk blockade of the phrenic nerve, nor does it have the potential to cause pneumothorax, making it an ideal option for day case surgery. Historically, single-injection techniques have not provided reliable blockade in the musculocutaneous and radial nerve territories, but success rates have greatly improved with multiple-injection techniques whether using nerve stimulation or US guidance. Complete, reliable, rapid, and safe blockade of the arm is now achievable. The authors concluded that axillary nerve block is a safe and effective regional anesthetic technique suitable for a wide variety of procedures, for both in-patient and out-patient care]; US guidance has allowed improved efficacy with smaller volumes of local anesthetic. Direct visualization of block performance and local anesthetic injection, though inherently safer, does not completely eliminate the risk of intra-vascular and intra-neural injection, and care should be continually exercised using standard safety precautions of slow, careful, fractionated injections to prevent and minimize the risks associated with the technique.

Thallaj et al (2015) tested the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN) can be achieved under US guidance using a small volume of local anesthetic. A total of 28 adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using 1-ml of 2 % lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. The ICBN appeared as a hyper-echoic structure. The nerve diameter was 2.3 ± 0.28 mm, and the depth was 9 ± 0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3 ± 1.6 cm anteriorly; 6.2 ± 2.9 cm posteriorly; 9.4 ± 2.9 cm proximally; and 9.2 ± 4.4 cm distally. Intercostobrachial nerve blockade using 1-ml of local anesthetic was successful in all cases. The authors concluded that this study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade. These researchers stated that this technique can be used as a supplemental block for upper limb anesthesia. They recommended further studies to support and apply these findings to improve patient care.

Wijayasinghe et al (2016) stated that persistent pain after breast cancer surgery (PPBCS) affects 25 to 60 % of breast cancer survivors and damage to the ICBN has been implicated as the cause of this predominantly neuropathic pain. Local anesthetic blockade of the ICBN could provide clues to pathophysiological mechanisms as well as aiding diagnosis and treatment of PPBCS but has never been attempted. In a prospective, pilot study, these researchers examined the feasibility of ICBN blockade and evaluated its effects on pain and sensory function in patients with PPBCS. This trial was performed in 2 parts: Part 1 determined the sonoanatomy of the ICBN and part 2 examined the effects of the US-guided ICBN blockade in patients with PPBCS. Part 1: 16 unoperated, pain-free BC patients underwent systematic ultrasonography to establish the sonoanatomy of the ICBN. Part 2: 6 patients with PPBCS who had pain in the axilla and upper arm were recruited for the study. Summed pain intensity (SPI) scores and sensory function were measured before and 30 mins after the block was administered. SPI is a combined pain score of numerical rating scale (NRS) at rest, movement, and 100 kPa pressure applied to the maximum point of pain using pressure algometry (max = 30). Sensory function was measured using quantitative sensory testing (QST), which consisted of sensory mapping, thermal thresholds, supra-threshold heat pain perception as well as heat and pressure pain thresholds. The ICBN block was performed under US-guidance and 10 ml 0.5 % bupivacaine was injected. Outcome measures included the ability to perform the ICBN block and its analgesic and sensory effects. Only the second intercostal space could be observed on US, which was adequate to perform the ICBN block. The mean difference in SPI was -9 NRS points (95 % confidence interval [CI]: -14.1 to -3.9; p = 0.006). All patients had pre-existing areas of hypoesthesia that decreased in size in 4/6 patients following the block. The authors successfully blocked the ICBN using US-guidance and demonstrated an analgesic effect in patients in PPBCS calling for placebo-controlled studies. The main drawback of this pilot study was its small sample size (n = 6), but despite this, a statistically significant effect was observed. These researchers stated that the premise of this study was to examine the feasibility of a randomized controlled trial (RCT) and these findings suggested that a RCT is needed to determine the role of ICBN blockade in PPBCS.

Magazzeni et al (2018) stated that for superficial surgery of antero-medial and postero-medial surfaces of the upper arm, the medial brachial cutaneous nerve (MBCN) and the ICBN must be selectively blocked, in addition to an axillary brachial plexus block. Ina randomized study, these researchers compared efficacy of US-guided (USG) versus conventional block of the MBCN and the ICBN. A total of 84 patients, undergoing upper limb surgery, were randomized to receive either USG (n = 42) or conventional (n = 42) block of the MBCN and the ICBN with 1 % mepivacaine. Sensory block was evaluated using light-touch on the upper and lower half of the antero-medial and postero-medial surfaces of the upper arm at 5, 10, 15, 20 mins after nerve blocks. The primary outcome was the proportion of patients who had no sensation in all 4 regions innervated by the MBCN and the ICBN at 20 mins. Secondary outcomes were onset time of complete anesthesia, volume of local anesthetic, tourniquet tolerance, and quality of US images. In the USG group, 37 patients (88 %) had no sensation at 20 mins in any of the 4 areas tested versus 8 patients (19 %) in the conventional group (p < 0.001). When complete anesthesia was obtained, it occurred within 10 mins in more than 90 % of patients, in both groups. Mean total volumes of local anesthetic used for blocking the MBCN and the ICBN were similar in the 2 groups; US images were of good quality in only 20 (47.6 %) of 42 patients; 41 patients (97.6 %) who received USG block were comfortable with the tourniquet versus 16 patients (38.1 %) in the conventional group (p < 0.001). The authors concluded that US guidance improved the efficacy of the MBCN and ICBN blocks.

Interscalene Nerve Block

Rajpal et al (2016) noted that post-operative neurologic symptoms after interscalene block and shoulder surgery have been reported to be relatively frequent. These investigators evaluated 300 patients for neurologic symptoms after low-volume, US-guided interscalene block and arthroscopic shoulder surgery (ASS). Patients underwent US-guided interscalene block with 16 to 20 ml of 0.5 % bupivacaine or a mix of 0.2 % bupivacaine/1.2 % mepivacaine solution, followed by propofol/ketamine sedation for ambulatory ASS. Patients were called at 10 days for evaluation of neurologic symptoms, and those with persistent symptoms were called again at 30 days, at which point neurologic evaluation was initiated. Details of patient demographics and block characteristics were collected to assess any association with persistent neurologic symptoms; 6 of 300 patients reported symptoms at 10 days (2 %), with 1 of these patients having persistent symptoms at 30 days (0.3 %). This was significantly lower than rates of neurologic symptoms reported in pre-US investigations with focused neurologic follow-up and similar to other studies performed in the US era. There was a modest correlation between the number of needle re-directions during the block procedure and the presence of post-operative neurologic symptoms. The authors concluded that US guidance of interscalene block with 16- to 20-ml volumes of local anesthetic solution resulted in a lower frequency of post-operative neurologic symptoms at 10 and 30 days as compared with investigations in the pre-US period.

Fuzier et al (2016) performed a cross-sectional survey study on French practice in US-guided regional anesthesia. A questionnaire (demographic data, assessment of the likely benefits of US, and its use in daily practice: blocks and hygiene) was emailed to all members of the French-speaking association of anesthesiologists involved in regional anesthesia. The questionnaire was filled out and returned by 634 experienced anesthesiologists. An US machine was available in 94 % of cases; US-guided regional anesthesia has become the gold standard technique for 3/4 of responders. Interscalene, popliteal sciatic and femoral nerve blocks were performed by more than 90 % of responders, most frequently under US supervision. Conversely, US guidance was rarely used for spinal or deep nerve blocks. A specific sterile sheath was used in only 43 % of cases. The authors concluded that the present study confirmed that US guidance has gained in popularity for many superficial, but not deep, regional anesthesia procedures in France.

Kolny et al (2017) stated that interscalene brachial plexus block (ISBPB) is an effective regional anesthesia technique for shoulder surgeries. The superiority of the popular US-guided blocks over peripheral nerve stimulator (PNS)-confirmed blocks remains unclear. In this study, the efficacy of these different block techniques was compared. This prospective, randomized, clinical study included 109 patients (American Society of Anesthesiologists [ASA] grades I-III) who receive 20 ml 0.5 % ropivacaine with US-guided blocks (U group), PNS-confirmed blocks (N group), or US-guided and PNS-confirmed blocks (dual guidance; NU group) for elective shoulder arthroscopy. Block onset time, duration, and effectiveness on the Lovett rating scale (LRS) were assessed. There was no statistically significant inter-group difference in duration of block performance, irrespective of the technique (p = 0.232). Onset time of complete warmth sensation loss (p < 0.001) and muscle strength abolition (p < 0.001) was significantly longer and mean LRS score distribution was significantly higher in the N group than in the other groups (p < 0.001). These findings showed a statistically significant correlation between the performance of the used block technique and the necessity of conversion to general anesthesia because of insufficient block in the N group (58.54 %) than in the U (24.44 %) and NU (19.57 %) groups. The authors stated that in a majority of studies, US guidance tended to be superior to PNS assistance for ISBPB. Compared to PNS assistance, US guidance led to faster onset time of ISBPB, lowered the rate of conversions to general anesthesia, and improved LRS scores. They concluded that PNS-confirmed needle placement was not necessary to ensure effectiveness of US-guided blocks as evidenced by the low rate of conversion to general anesthesia in this study. Nevertheless, the dual guidance technique (US guidance and PNS confirmation) was recommended to reduce the risk of complications and might be considered the regional anesthesia of choice for shoulder surgery.

In a RCT, Woo et al (2018) examined if ISBPB using a lower concentration of local anesthetic would reduce the incidence of post-thoracotomy ipsilateral shoulder pain with assessment of pulmonary function in patients who underwent a lung lobectomy. A total of 44 patients who underwent a lung lobectomy were randomly assigned to either the control or the interscalene block (ISB) group. Single-shot ISB on the surgical site side was performed using ropivacaine 10-ml 0.25 % including 5-mg dexamethasone under US guidance in the ISB group. Lobectomy and continuous paravertebral block were performed under general anesthesia. The presence of ipsilateral shoulder pain and post-operative adverse events (AEs) were assessed. Pulmonary function tests were performed pre-operatively, the day after surgery, and the day after removing the chest tube. The incidence of ipsilateral shoulder pain was significantly lower in the ISB group than in the control group (54.5 % versus 14.3 %, p = 0.006) with an overall incidence of 34.9 %. Post-operative AEs were similar between the groups, with no patients presenting symptoms of respiratory difficulty. Significant reductions in pulmonary function were observed in all patients after lobectomy; however, no significant difference in any of the pulmonary function test variables was observed post-operatively between the groups. The authors concluded that ISB using 10-ml of 0.25 % ropivacaine including 5-mg dexamethasone reduced the incidence of post-thoracotomy ipsilateral shoulder pain and did not result in additional impairment of pulmonary function.

In a prospective, randomized, clinical study, Stasiowski et al (2018a) evaluated the effect of the ISBPB on the occurrence rate of Horner's syndrome. A total of 108 randomly selected patients of ASA I-III status were scheduled for elective shoulder arthroscopy. The patients received 20 ml of 0.5 % ropivacaine either with US-guided ISBPB (U), PNS-confirmation ISBPB (N), or US-guided, PNS-confirmed ISBPB (dual guidance; NU). These researchers observed that Horner's syndrome developed in 12 % of the N group, 6 % of the NU group, and 9 % of the U group. The differences in the rates were not statistically significant (p = 0.616). Regardless of the technique used to induce ISBPB, this study did not demonstrate any particular anthropometric parameter that pre-disposed patients to the development of Horner's syndrome. Interestingly, these findings showed that NU patients with Horner's syndrome were significantly younger than NU patients without Horner's syndrome. The authors concluded that the precision of ISBPB by use of the dual guidance technique may reduce the rate of Horner's syndrome. The higher water concentration in the prevertebral spaces of younger patients may create better conditions for the diffusion of ropivacaine, which may result in a statistically significant higher Horner's syndrome rate.

In a prospective, randomized, clinical study, Stasiowski et al (2018b) examined the influence of anthropometric parameters and ISBPB on the quality of post-operational analgesia. A total of 109 randomly selected patients of ASA I-III status were scheduled for elective shoulder arthroscopy. Reasons for non-inclusion were as follows: neurological deficit in the upper arm; allergies to amide Las; coagulopathy; and pregnancy. Patients were divided into 3 groups – group U, group N, or group NU. These researchers observed that the studied groups did not differ in mean time of sensory and motor block terminations and, surprisingly, in each group in individual cases the sensory block lasted up to 890 to 990 mins providing satisfactory long-lasting post-operational analgesia in patients receiving ISBPB. These investigators observed a negative correlation between body mass index (BMI) and termination of the motor block and a positive correlation between age and termination of the sensory block in group U in comparison with the 2 other groups. They found a positive correlation between the male gender and termination of the motor block in patients in group N in comparison with 2 other groups. The authors concluded that in this study, patients received satisfactory analgesia in the post-operational period no matter what technique was used regardless of their age, gender or potentially uncommon anthropometry.

Pectoralis Nerve Block (PEC 1 and PEC 2) for the Management of Post-Operative Pain Following Mastectomy

In a prospective RCT, Neethu et al (2018) examined the analgesic efficacy of Us-guided combined pectoral nerve blocks (PECS) I and II in patients scheduled for surgery for breast cancer. A total of 60 American Society of Anesthesiologists (ASA) status I to II women, aged 18 to 70 years were enrolled in this study. Patients were randomized into 2 groups (30 patients in each group), PECS (P) group and control (C) group. In group P, patients received both general anesthesia and US-guided combined PECS I and II. In group C, patients received only general anesthesia (GA). These researchers noted pain intensity at rest and during abduction of the ipsilateral upper limb, incidence of post-operative nausea and vomiting (PONV); patient's satisfaction with post-operative analgesia and maximal painless abduction at different time-intervals in both groups. There was significant decrease in the total amount of fentanyl requirement in the in P group {(140.66 ± 31.80 μg) and (438 ± 71.74 μg)} in comparison to C group {(218.33 ± 23.93 μg) and (609 ± 53.00 μg)} during intra-operative and post-operative period up to 24 hours, respectively. The time to first analgesic requirement was also more in P group (44.33 ± 17.65 mins) in comparison to C group (10.36 ± 4.97 mins) during post-operative period. There was less limitation of shoulder movement (pain free mobilization) on the operative site at 4 and 5 hours after surgery in P group in comparison to C group. However there was no difference in the incidence of PONV (22 out of 30 patients in group P and 20 out of 30 patients in group C) but patients in group P had a better satisfaction score with post-operative analgesia than C group having a p value of < 0.001(Score 1; 5 versus 20; Score 2; 12 versus 9; Score 3; 13 versus 1). The authors concluded that US-guided combined PECS were an effective modality of analgesia for patients undergoing breast surgeries during peri-operative period.

Versyck et al (2019) noted that surgery is the primary therapeutic intervention for breast cancer and can result in significant post-operative pain. These investigators searched the current literature and performed a meta-analysis in order to compare the analgesic efficacy of the PECS II block with systemic analgesia alone and with a thoracic paravertebral block for breast cancer surgery. Primary outcome was post-operative opioid consumption in the first 24 hours after surgery. Secondary outcomes were pain scores at 0, 3, 6, 9 and 24 hours after surgery, intra-operative opioid consumption, time to first analgesic request and incidence of post-operative nausea and vomiting. They identified 13 RCTs that included 815 patients. The Pecs II block significantly reduced post-operative opioid consumption (standardized mean difference [SMD]: -13.64 mg oral morphine equivalents; 95 % confidence interval [CI]: -21.22 to -6.05; p < 0.01) and acute post-operative pain at all intervals in the first 24 hours after surgery compared with systemic analgesia alone. Compared with the thoracic paravertebral block, the Pecs II block resulted in similar post-operative opioid consumption (SMD: -8.73 mg oral morphine equivalents; 95 % CI: -18.16 to 0.69; p = 0.07) and post-operative pain scores after first measurement. The authors concluded that the PECSs II block offered improved analgesic efficacy compared with systemic analgesia alone and comparable analgesic efficacy to a thoracic paravertebral block for breast cancer surgery.

Zhao et al (2019) stated that many types of regional nerve blocks have been used during anesthesia for modified radical mastectomy. In recent years, the use of pectoral nerve (PECS) block has gained importance in post-operative analgesia, but there are still controversies regarding its efficacy. There is especially no consensus on the optimal type of PECS block to be used. These researchers evaluated the analgesic efficacy of the PECS block after radical mastectomy. They searched PubMed, Embase, and the Cochrane library for RCTs for studies regarding PECS versus GA that were published prior to May 31, 2018. Outcome measures such as intra- and post-operative consumption of opioids, PONV, need for post-operative rescue analgesia, and pain scores were analyzed. After quality evaluation and data extraction, a meta-analysis was performed using Review Manager 5.3 software, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used for rating the quality of evidence. A total of 8 RCTs and 2 cohort studies involving 993 patients were eligible. Compared with the GA group, the PECS block group effectively reduced the intra-operative and post-operative use of opioid drugs, incidence of PONV, need for post-operative rescue analgesia, and pain scores within 0 to 6 hours after surgery. However, subgroup analysis showed that PECS I block did not have a significant advantage in reducing the intra- and post-operative consumption of opioids. Results for each outcome indicator were confirmed as having a high or moderate level of evidence. The authors concluded that even considering the limitations (evaluations of efficacy in different age groups and for chronic pain were not carried out) of this meta-analysis, it can be concluded that the PECS II block is an effective anesthetic regimen in modified radical mastectomy that can effectively reduce the intra- and post-operative consumption of opioids, post-operative PONV, and the need for post-operative rescue analgesia and can alleviate early pain (0 to 6 hours) after surgery.

In a prospective, randomized, single-blinded study, Altıparmak et al (2019) compared the effects of US-guided modified PECS block and erector spinae plane (ESP) block on post-operative opioid consumption, pain scores, and intra-operative fentanyl need of patients undergoing unilateral modified radical mastectomy surgery. A total of 40 patients (ASA I-II) were allocated to 2 groups. After exclusion, 38 patients were included in the final analysis (18 patients in the PECS groups and 20 in the ESP group). Modified pectoral nerve block was performed in the PECS group and erector spinae plane block was performed in the ESP group. Post-operative tramadol consumption and pain scores were compared between the groups. Also, intra-operative fentanyl need was measured. Post-operative tramadol consumption was 132.78 ± 22.44 mg in PECS group and 196 ± 27.03 mg in ESP group (p = 0.001); NRS scores at the 15th and 30th mins were similar between the groups. However, median NRS scores were significantly lower in PECS group at the post-operative 60th min, 120th min, 12th hour and 24th hour (p = 0.024, p = 0.018, p = 0.021 and p = 0.011, respectively). Intra-operative fentanyl need was 75 mg in PECS group and 87.5 mg in ESP group. The difference was not statistically significant (p = 0.263). The authors concluded that modified PECS block reduced post-operative tramadol consumption and pain scores more effectively than ESP block after radical mastectomy surgery.

Ueshima et al (2019) noted that since the original description in 2011, the array of PECS has evolved. The PECS block in conjunction with GA can decrease an additional analgesic in peri-operative period for breast cancer surgeries. Current literature on the PECS block has reported 3 several types (PECS I, PECS II, and serratus plane blocks). The PECS I block is the same as to the first injection in the PECS II block. The second injection in the PECS II block and the serratus plane block blocks intercostal nerves (T2 to T6) and provides an analgesic for the breast cancer surgery. However, the PECS I block (or first injection in the PECS II block) has no analgesic, because both lateral and medial pectralis nerve blocks are motor nerves. PECS block in previous reports, when added to opioid-based GA, may improve analgesia and decrease narcotic use for breast cancer surgery. Moreover, PECS block compares favorably with other regional techniques for selected types of surgery. A major limitation of the PECS block is that it could not block the internal mammary region. Thus, some studies have reported its ability to block the anterior branches of the intercostal nerve. The authors concluded that PECS block is an effective analgesic tool for the anterolateral chest; in particular, the PECS block can provide more effective analgesia for breast cancer surgery.

Senapathi et al (2019) stated that combined regional and GA are often used for the management of breast cancer surgery. Thoracic spinal block, thoracic epidural block, thoracic paravertebral block, and multiple intercostal nerve blocks are the regional anesthesia techniques that have been used in breast surgery, but some anesthesiologists are not comfortable because of the complication and side effects. In 2012, Blanco et al introduced pectoralis nerve (PECS) II block or modified PECS block as a novel approach to breast surgery. These researchers determined the effectiveness of combined US-guided PECS II block and GA for reducing intra- and post-operative pain from modified radical mastectomy. A total of 50 patients undergoing modified radical mastectomy with GA were divided into 2 groups randomly (n = 25), to either PECS (P) group or control (C) group. Ultrasound-guided PECS II block was done with 0.25 % bupivacaine (P group) or 0.9 % NaCl (C group). Patient-controlled analgesia (PCA) was used to control post-operative pain. Intra-operative opioid consumption, post-operative visual analog scale (VAS) score, and post-operative opioid consumption were measured. Intra-operative opioid consumption was significantly lower in P group (p ≤ 0.05); VAS score at 3, 6, 12, and 24 hours post-operative were significantly lower in P group (p ≤ 0.05); 24 hours post-operative opioid consumption was significantly lower in P group (p ≤ 0.05). There were no complications following PECS block in both groups, including pneumothorax, vascular puncture, and hematoma. The authors concluded that combined US-guided PECS II block and GA were effective in reducing pain both intra- and post-operatively in patients undergoing modified radical mastectomy.

Lovett-Carter et al (2019) noted that several studies have evaluated the effect of PECS to improve post-operative analgesia following breast cancer surgery resulting in contradictory findings. These investigators examined the effect of PECS blocks on post-operative analgesia in women following mastectomies. They performed a quantitative systematic review in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Articles of RCTs that compared PECS block (types I and II) to a control group in patients undergoing mastectomy were included. The primary outcome was total opioid consumption 24 hours after surgery. Secondary outcomes included pain scores and side effects. Meta-analysis was performed using the random effect model. A total of 7 RCTs with 458 patients were included in the analysis. The effect of PECS blocks on post-operative opioid consumption compared with control revealed a significant effect, weighted mean difference (WMD) (95 % CI: -4.99 (-7.90 to -2.08) mg intravenous morphine equivalents (p = 0.001). In addition, post-operative pain compared with control was reduced at 6 hours after surgery: WMD (95 % CI): -0.72 (-1.37 to -0.07), p = 0.03, and at 24 hours after surgery: WMD (95 % CI): -0.91 (-1.81 to -0.02), p = 0.04. The authors concluded that this quantitative analysis of RCTs demonstrated that the PECS block was effective for reducing post-operative opioid consumption and pain in patients undergoing mastectomy. The PECS block should be considered as an effective strategy to improve analgesic outcomes in patients undergoing mastectomies for breast cancer treatment.

Piriformis Muscle Injection

In a cadaveric study, Finnoff et al (2008) compared the accuracy of ultrasound (US)-guided piriformis injections with fluoroscopically guided contrast-controlled piriformis injections. A total of 20 piriformis muscles in 10 un-embalmed cadavers were injected with liquid latex using both fluoroscopically guided contrast-controlled and US-guided injection techniques. All injections were performed by the same experienced individual. Two different colors of liquid latex were used to differentiate injection placement for each procedure, and the injection order was randomized. The gluteal regions were subsequently dissected by an individual blinded to the injection technique. Colored latex observed within the piriformis muscle, sheath, or both was considered an accurate injection. A total of 19 of 20 US-guided injections (95 %) correctly placed the liquid latex within the piriformis muscle, whereas only 6 of the 20 fluoroscopically guided contrast-controlled injections (30 %) were accurate (p = 0.001). The liquid latex in 13 of the 14 missed fluoroscopically guided contrast-controlled piriformis injections and the single missed US-guided injection was found within the gluteus maximus muscle. In the single remaining missed fluoroscopically guided contrast-controlled piriformis injection, the liquid latex was found within the sciatic nerve. The authors concluded that in this cadaveric model, US-guided piriformis injections were significantly more accurate than fluoroscopically guided contrast-controlled injections. Despite the use of bony landmarks and contrast, most of the fluoroscopically attempted piriformis injections were placed superficially within the gluteus maximus. Clinicians performing piriformis injections should be aware of the potential pitfalls of fluoroscopically guided contrast-controlled piriformis injections and consider using US guidance to ensure correct needle placement.

The authors stated that this study had several drawbacks. First, a single investigator performed all injections. The investigator was pain medicine fellowship-trained, was board-certified in pain medicine, and had extensive procedural experience with both fluoroscopically guided and US‐guided procedures. In consideration of the relatively poor accuracy of the fluoroscopically guided piriformis injection, it was worth noting that he had several years' more experience with the fluoroscopic than with the US technique. Nonetheless, the results of this investigation may not be applicable to other clinicians with different training and experiential backgrounds. Second, this investigation used un-embalmed cadavers rather than live participants. The study necessitated 2 injections in each piriformis muscle and "surgical" confirmation of injectate placement via dissection, a design that could not be completed in live individuals. These researchers did not think that the use of cadavers appreciably affected their findings. Their contrast patterns were similar to those observed in live individuals, so it was unlikely that the cadaver model biased the results against fluoroscopy. On the contrary, the inability to take full advantage of the dynamic soft tissue imaging capabilities of US may have negatively biased the accuracy of the US technique. For example, the inferior gluteal artery as imaged via Doppler techniques may be used in live persons as a reference mark for the inferior border of the piriformis muscle as well as the location of the sciatic nerve. These investigators thought that the results of this study appeared to be transferable to the clinical setting.

Blunk et al (2013) noted that patients presenting with buttock pain syndromes are common. Up to 8 % of these conditions may be attributed to piriformis syndrome. Included in several therapeutic and diagnostic approaches, injections directly into the piriformis muscle may be performed. Because the muscle lies very close to neurovascular structures, electromyographic (EMG), fluoroscopic, computed tomographic (CT), and magnetic resonance imaging (MRI) guidance have been employed. In few studies, an US-guided technique was used to inject a local anesthetic into the piriformis muscle without impairing adjacent neuronal structures. In a feasibility study in healthy human subjects, These researchers confirmed US-guided injections by MRI. In 10 male human subjects, US-guided injections of 3 ml of a local anesthetic into the piriformis muscle were performed. Directly after the injection, the subjects were placed in an MRI scanner, and the placement of the liquid depot was confirmed by MRI imaging. Somatosensory deficits were evaluated after the injection. The MRI showed that 9 of 10 of the injections were correctly placed within the piriformis muscle. The distance of the depot to the sciatic nerve decreased over time due to dispersion, but the nerve itself was not reached in the MRI. Only 1 subject experienced slight, short-term sensorimotor deficits. The authors concluded that MRI confirmed the correct placement of the local anesthetic within the muscle. The dispersion of the fluid 30 mins after the injection could be visualized. Moreover, only 1 subject experienced slight motor deficits without anatomical correlate. These researchers stated that this US-guided method will be further employed in ongoing clinical studies.

Fabregat et al (2014) noted that approximately 6 % to 8 % of lumbar pain cases, whether associated with radicular pain or not, may be attributed to the presence of piriformis muscle syndrome. Available treatments, among others, include pharmacotherapy, physical therapy, and injections of different substances into the muscle. Various methods have been used to confirm correct needle placement during these procedures, including EMG, fluoroscopy, CT, or MRI. Ultrasonography has now become a widely used technique and therefore may be an attractive alternative for needle guidance when injecting this muscle. In a feasibility study, these researchers examined the reliability of US in piriformis injection of patients with piriformis syndrome. A tot of 10 patients with piriformis muscle syndrome were injected with botulinum toxin A (BTX-A) using a US-guided procedure. Then patients were administered 2 ml iodinated contrast and were then transferred to the CT scanner, where they underwent pelvic and hip imaging to assess intra-muscular (IM) distribution of the iodinated contrast. Of all 10 study patients (8 women, 2 men), 9 had IM or intra-fascial contrast distribution. Distribution did not go deeper than the piriformis muscle in any of the patients. The absence of contrast (intravascular injection) was not observed in any case. The authors concluded that US-guided puncture may be a reliable and simple procedure for injection of the piriformis muscle, as long as good education and training are provided to the operator. These researchers stated that US has a number of advantages over traditional approaches, including accessibility and especially no ionizing radiation exposure for both health care providers and patients. Moreover, they noted that published data regarding US-guided treatments were still very limited; and further studies should focus on outcome and safety of US-guided pain interventions compared to traditional imaging techniques such as fluoroscopy.

Fowler et al (2014) stated that piriformis muscle injections are most often performed using fluoroscopic guidance; however, US guidance has recently been described extensively in the literature. No direct comparisons between the 2 techniques have been performed. In a randomized, comparative trial, these researchers compared the efficacy and efficiency of fluoroscopic- and US-guided techniques. A total of 28 patients with a diagnosis of piriformis syndrome, based on history and physical examination, who had failed conservative treatment were enrolled in the study. Patients were randomized to receive the injection either via US or fluoroscopy. Injections consisted of 10 ml of 1 % lidocaine with 80 mg of triamcinolone. The primary outcome measure was numeric pain score (NPS), and secondary outcome measures included functional status as measured by the Multidimensional Pain Inventory, patient satisfaction as measured by the Patient Global Impression of Change scale, and procedure timing characteristics. Outcome data were measured pre-procedure, immediately post-procedure, and 1 to 2 weeks and 3 months post-procedure. These investigators found no statistically significant differences in NPS, patient satisfaction, procedure timing characteristics, or most functional outcomes when comparing the 2 techniques. Statistically significant differences between the 2 techniques were found with respect to the outcome measures of household chores and outdoor work. The authors concluded that US-guided piriformis injections provided similar outcomes to fluoroscopically guided injections without differences in imaging, needling, or overall procedural times.

Misirlioglu et al (2015) stated that piriformis syndrome (PS), which is characterized by pain radiating to the gluteal region and posterior leg, is accepted as one of the causes of sciatalgia. Although the importance of local piriformis muscle injections whenever PS is clinically suspected has been shown in many studies, there are not enough studies considering the clinical efficacy of these injections. In a prospective, double-blinded, randomized controlled trial (RCT), these investigators examined the differences between local anesthetic (LA) and LA + corticosteroid (CS) injections in the treatment of PS. A total of 57 patients having unilateral hip and/or leg pain with positive FAIR test and tenderness and/or trigger point at the piriformis muscle were evaluated. Out of 50 patients randomly assigned to 2 groups, 47 patients whose pain resolved at least 50 % from the baseline after the injection were diagnosed as having PS. The first group (n = 22) received 5 ml of lidocaine 2 % while the second group (n = 25) received 4 ml of lidocaine 2 % + 1 ml of betamethasone under US-guidance. Outcome measures included numeric rating scale (NRS) and Likert analogue scale (LAS). No statistically significant difference (p > 0.05) was detected between the groups in NRS score values at resting (p = 0.814), night (p = 0.830), and in motion (p = 0.145), and LAS values with long duration of sitting (p = 0.547), standing (p = 0.898), and lying (p = 0.326) with evaluations at baseline, first week, and first and third months after the injection. A statistically highly significant (p < 0.005) reduction of pain was evaluated through NRS scores at resting (p = 0.001), in motion (p = 0.001), and at night (p = 0.001) and LAS values with long duration of sitting (p = 0.001), standing (p = 0.001), and lying (p = 0.001) in both of the groups. The authors concluded that LA injections for the PS were found to be clinically effective. However, addition of CS to LA did not give an additional benefit.

Payne (2016) described the techniques for performing US-guided procedures in the hip region, including intra-articular hip injection, iliopsoas bursa injection, greater trochanter bursa injection, ischial bursa injection, and piriformis muscle injection. The author stated that US is commonly used to evaluate hip region pathologic conditions and to guide interventions in the hip region for diagnostic and therapeutic purposes; US confers many advantages compared with other commonly used imaging modalities, including real-time visualization of muscles, tendons, bursae, neurovascular structures, and the needle during an intervention. The author stated that US-guided injection techniques have been described for many commonly performed procedures in the hip region, and many studies have been performed demonstrating the safety and accuracy of these techniques.

In a prospective study, Terlemez and Ercalık (2019) examined the effect of a piriformis injection on neuropathic pain in patients with PS. A total of 30 patients with unilateral hip and/or leg pain, a positive FAIR test (increased H-reflex latency with Flexion, Adduction and Internal Rotation), and a trigger point at the piriformis muscle were enrolled in this study. All of the patients exhibited neuropathic pain scored according to the Douleur Neuropathique 4 (DN4) of greater than or equal to 4 for at least 6 months. All of the patients received 4 ml of lidocaine 2 % + 1 ml of betamethasone to the piriformis muscle under US-guidance. The NRS, DN4, and the painDETECT (PD) questionnaire were used for outcome assessment. A statistically significant improvement was observed in all scores (p < 0.001) when both first week and first month results were compared with the baseline values. Comparison of the first week results with those of the first month revealed a statistically significant improvement in only the NRS and PD scores (p < 0.001). The greatest improvement in all scores was observed in the first week after the injection. A mild increase was observed in all scores at the first month compared to the first week. The authors concluded that a piriformis injection was found to be effective for both somatic and neuropathic pain in PS patients.

Furthermore, an UpToDate review on "Approach to hip and groin pain in the athlete and active adult" (Johnson, 2020) states that "Treatment begins with physical therapy involving strengthening of the pelvic and hip region and stretching of the piriformis. Appropriate analgesics for neuropathic pain are taken as needed. Physical therapy is effective in the majority of cases. Ultrasound-guided glucocorticoid injections have been beneficial in some cases, and botulinum toxin injections have also been used. Surgery (typically a piriformis tenotomy) may be considered if symptoms are debilitating and persist despite conservative therapy".

Popliteal Nerve Block

Sinha and Chan (2004) stated that US is a novel method of nerve localization but its use for lower extremity blocks appeared limited with only reports for femoral 3-in-1 blocks. These investigators reported a case series of popliteal sciatic nerve blocks using US guidance to illustrate the clinical usefulness of this technology. The sciatic nerve was localized in the popliteal fossa by US imaging in 10 patients using a 4- to 7-MHz probe and the Philips ATL HDI 5,000 unit. Ultrasound imaging showed the sciatic nerve anatomy, the point at which it divides, and the spatial relationship between the peroneal and tibial nerves distally. Needle contact with the nerve(s) was further confirmed with nerve stimulation. Circumferential local anesthetic spread within the fascial sheath after injection appeared to correlate with rapid onset and completeness of sciatic nerve block. The authors concluded that their preliminary experience suggested that US localization of the sciatic nerve in the popliteal fossa was a simple and reliable procedure. It helped guide block needle placement and assessed local anesthetic spread pattern at the time of injection.

Perlas et al (2008) noted that real time US guidance is a recent development in the area of peripheral nerve blockade. There are limited data from prospective randomized trials comparing its efficacy to that of traditional nerve localization techniques. In the present study, these researchers tested the hypothesis that US guidance improved the success rate of sciatic nerve block at the popliteal fossa when compared with a nerve stimulator-guided technique. After Institutional Research Ethics Board approval and informed consent, a total of 74 patients undergoing elective major foot or ankle surgery were randomly assigned to receive a sciatic nerve block at the popliteal fossa guided by either US (group US, transverse view, needle in plane approach above the sciatic nerve bifurcation), or nerve stimulation (group NS, single injection, 10 cm proximal to the knee crease). A standardized local anesthetic admixture (15 ml of 2 % lidocaine with 1:200,000 epinephrine and 15 ml of 0.5 % bupivacaine) was used. Sensory and motor function was assessed by a blinded observer at pre-determined intervals for up to 1 hour. Block success was defined as a loss of sensation to pinprick within 30 mins in the distribution of both tibial and common peroneal nerves. Group US had a significantly higher block success rate than group NS (89.2 % versus 60.6 %, p = 0.005), while the procedure time was similar. The authors concluded that US guidance enhanced the quality of popliteal sciatic nerve block compared with single injection, nerve stimulator-guided block using either a tibial or peroneal endpoint; US guidance resulted in higher success, faster onset, and progression of sensorimotor block, without an increase in block procedure time, or complications.

van Geffen et al (2009) stated that the direct visualization of nerves and adjacent anatomical structures may make US the preferred method for nerve localization. In a prospective, randomized study, these investigators examined if, for distal sciatic nerve block in the popliteal fossa, an US-guided technique would result in the use of less local anesthetic without changing block characteristics and quality. Using electrical nerve stimulation or US guidance, the nerve was identified in 2 groups of 20 patients scheduled for lower limb surgery. Hereafter lignocaine 1.5 % with adrenaline 5 microg/ml was injected. The attending anesthesiologist assessed the injected volume. Significantly less local anesthetic was injected in the US group compared to the nerve stimulation group (17 versus 37 ml, p < 0.001), while the overall success rate was increased (100 % versus 75 %; p = 0.017). The authors concluded that the use of US localization for distal sciatic nerve block in the popliteal fossa reduced the required dose of local anesthetic significantly, and was associated with a higher success rate compared to nerve stimulation without changing block characteristics.

Bendtsen et al (2011) tested the hypothesis that US-guided catheter placement improved the success rate of continuous sciatic nerve sensory blockade compared with catheter placement with nerve stimulation guidance. After research ethics committee approval and informed consent, a total of 100 patients scheduled for elective major foot and ankle surgery were randomly allocated to popliteal catheter placement either with US or nerve stimulation guidance. The primary outcome was the success rate of sensory block the first 48 post-operative hours. Successful sensory blockade was defined as sensory loss in both the tibial and common peroneal nerve territories at 1, 6, 24, and 48 hours post-operatively. The US group had significantly higher success rate of sensory block compared with the nerve stimulation group (94 % versus 79 %, p = 0.03). US compared with nerve stimulation guidance also entailed reduced morphine consumption (median of 18 mg [range of 0 to 159 mg] versus 34 mg [range of 0 to 152 mg], respectively, p = 0.02), fewer needle passes (median of 1 [range of 1 to 6] versus 2 [range of 1 to 10], respectively, p = 0.0005), and greater patient satisfaction (median numeric rating scale 9 [range of 5 to 10] versus 8 [range of 3 to 10)] respectively, p = 0.0006) during catheter placement. The authors concluded that US guidance used for sciatic catheter placement improved the success rate of sensory block, number of needle passes, patient satisfaction during catheter placement, and morphine consumption compared with nerve stimulation guidance.

In a prospective, randomized study, Cataldo et al (2012) compared the success rate and performance time of popliteal block during resident's training for regional anesthesia by using nerve stimulation (NS) or combined nerve stimulation and US (NS + US). A total of 70 adult patients undergoing hallux valgus surgery were randomly assigned to receive sciatic nerve block at popliteal fossa with US+NS or NS alone with a double injection technique for peroneal and tibial branches, respectively. Two residents experienced with nerve stimulator performed the procedures after a learning phase concerning US. A local anesthetic solution, containing 10 ml of 0.75 % ropivacaine and 10 ml of 2 % lidocaine was used: 12 ml were infiltrated close the tibial nerve, and 8ml were infiltrated close the common peroneal nerve. Block success rate, sensory block onset time, block performance time were evaluated. Recourse to general anesthesia was considered as failure. No differences were detected in success rate and onset time of sensory block between the 2 groups (p > 0.05). The time to block tibial nerve and the overall block time were significantly faster in US+NS group (p < 0.05). The authors concluded that US guidance for popliteal nerve block resulted in similar success rate with a faster procedure time when compared with nerve stimulator, thus providing a possible effect on resident education and operating room efficiency.

In a randomized, single-blinded, clinical trial, Lam et al (2014) compared procedural times and related outcomes for US- versus nerve stimulation-guided lateral popliteal-sciatic nerve blockade specifically in obese patients. With Institutional Review Board approval and informed consent, patients with a body mass index (BMI) greater than 30 kg/m(2) who were scheduled for foot/ankle surgery and desiring a peripheral nerve block were offered enrollment. Study patients were randomly assigned to receive a lateral popliteal-sciatic nerve block under either US or nerve stimulation guidance. The patient and assessor were blinded to group assignment. The primary outcome was procedural time in seconds. Secondary outcomes included number of needle re-directions, procedure-related pain, patient satisfaction with the block, success rate, sensory and motor onset times, block duration, and complication rates. A total of 24 patients were enrolled and completed the study. All patients had successful nerve blocks. The mean procedural times (SD) were 577 (57) seconds under nerve stimulation and 206 (40) seconds with US guidance (p <0 .001; 95 % CI: 329 to 412 seconds). Patients in the US group had fewer needle re-directions and less procedure-related pain, required less opioids, and were more satisfied with their block procedures. There were no statistically significant differences in other outcomes. The authors concluded that the findings of this study showed that, for obese patients undergoing lateral popliteal-sciatic nerve blocks, US guidance reduced the procedural time and procedure-related pain and increased patient satisfaction compared to nerve stimulation while providing similar block characteristics.

In a prospective, randomized study, Karaarslan et al (2016) compared the efficacy, post-operative pain scores, adverse effects, additional analgesic requirements, and patient satisfaction scores of US-guided sciatic nerve block by popliteal approach with spinal anesthesia for hallux valgus correction surgery. A total of 60 patients scheduled for hallux valgus correction surgery were enrolled in this trial. Unilateral spinal block was performed on patients in the spinal anesthesia group. Popliteal block group patients received popliteal sciatic nerve block with guidance by both nerve stimulator and US. Durations of anesthetic and operative interventions and time until the initiation of surgery were recorded for both groups. Pain magnitude of the patients at the second, fourth, sixth, 12th, and 24th hours following anesthetic interventions were assessed with a visual analog scale (VAS). Adverse effects such as post-operative urinary retention and post-dural puncture headache were recorded. Also, patient satisfaction was recorded. Patients were interviewed by phone for anesthetic and operative complications at 72 hours post-operatively. Spinal anesthesia group patients exhibited hypotension, bradycardia, post-dural puncture headache, and urinary retention rates of 6.6 %, 3.3 %, 10 %, and 3.3 %, respectively. Popliteal block group patients showed none of these adverse effects. Moreover, VAS scores of the patients at the second, fourth, sixth, and 12th hours were significantly lower (p < 0.001, p = 0.003, p < 0.001, p < 0.001, respectively), post-operative first analgesic requirement times were significantly longer (p < 0.001), and pain satisfaction scores were significantly higher (p < 0.001) in the popliteal block group. The authors concluded that given the complications related to spinal anesthesia and its insufficiency to maintain analgesia postoperatively, they believed the preferred anesthetic method should be peripheral nerve blocks for hallux valgus correction surgeries. Level of Evidence = I.

Quadratus Lumborum Nerve Block for Post-Operative Pain Control After Abdominal Surgery

In a prospective RCT, Ishio et al (2017) determined the efficacy of US-guided posterior quadratus lumborum block (QLB) in treating post-operative pain following laparoscopic gynecologic surgery. A total of 70 adult patients scheduled for elective laparoscopic gynecological surgery under general anesthesia were enrolled in this trial. Patients were randomly assigned to either the QLB group or control group. In the QLB group, patients underwent posterior QLB with 20 ml of 0.375 % ropivacaine on each side. Patients were blinded to treatment. At 0, 1, 3, and 24 hours after anesthesia recovery, evaluator recorded the severity of post-operative pain in movement and at rest using a Numeric Rating Scale (NRS). These researchers also evaluated the severity of nausea using NRS and number of additional analgesics. Immediately after recovery from anesthesia, the NRS score for pain in movement did not differ significantly between groups; NRS scores for pain both in movement and at rest were significantly higher in the control group than in the QLB group at 1, 3, and 24 hours after recovery from anesthesia. The authors concluded that these findings suggested that posterior QLB significantly reduced post-operative pain in movement and at rest following laparoscopic gynecologic surgery.

Hussein (2018) stated that QLB has 4 approaches. However, there is difference between the 4 approaches regarding efficacy, safety and adverse effects. This investigator compared the analgesic effect between trans-muscular and intra-muscular approaches of the QLB in pediatric patients for elective lower abdominal surgery. A total of 54 patients aged 1 to 6 years were enrolled; patients of both genders were selected. Subjects were randomly classified into 2 groups: Group TQL included patients (n = 27) in whom bilateral QLB was performed using trans-muscular approach, and Group IQL included patients (n = 27) who underwent bilateral QLB using an intra-muscular approach. The primary outcome measure was the number of patients who required rescue analgesia in the first 24 hours. The secondary outcome measures were Face, Legs, Arms, Cry, Consolability (FLACC) score, heart rate, non-invasive blood pressure at 2, 4, 6, 12, and 24 hours post-operatively, and post-operative complications (e.g., local hematoma, quadriceps muscle weakness,). In the first 24 hours after surgery, 13 patients in the IQL group (48.1 %) required rescue analgesia, whereas only 5 patients in the TQL group (18.5 %) required rescue analgesia. The FLACC score was lower in the TQL group than the IQL group at all time intervals up to 24 hours post-operatively. In the TQL group, 8 patients (29.6 %) developed quadriceps weakness; whereas, only 1 patient (3.7 %) in the IQL group developed quadriceps weakness. The author concluded that TQL was better than IQL in the analgesic efficacy following the pediatric lower laparotomy.

Zhu et al (2019) stated that QLB is increasingly being used as a new abdominal nerve block technique. In some studies of mid and lower abdominal and hip analgesia, continuous QLB achieved favorable outcomes as an alternative to continuous intravenous analgesia with opioids. However, the use of continuous QLB for upper abdominal pain is less well characterized. In an open-label RCT, these investigators examined the effects of continuous anterior QLB (CQLB) on post-operative pain and recovery in patients undergoing open liver resection. A total of 63 patients underwent elective open liver resection were randomly divided into CQLB group (n = 32) and patient-controlled analgesia (PCA) group (n = 31). Patients in CQLB group underwent US-guided anterior QLB at the second lumbar vertebral transverse processes before general anesthesia, followed by post-operative CQLB analgesia. Patients in PCA group underwent continuous intravenous analgesia post-operatively. Post-operative NRS pain scores upon coughing and at rest, self-administered analgesic counts, rate of rescue analgesic use, time to first out-of-bed activity and anal flatus after surgery, and incidences of analgesic-related adverse effects were recorded. Post-operative NRS pain scores on coughing in CQLB group at different time-points and NRS pain score at 48 hours after surgery were significantly lower than those in PCA group (p < 0.05). Time to first out-of-bed activity and anal flatus after surgery in CQLB group were significantly earlier than those in PCA group (p < 0.05). No significant differences of post-operative self-administered analgesic counts, rate of post-operative rescue analgesic usage, or incidences of analgesic-related adverse effects were found between the 2 groups (p > 0.05). The authors concluded that US-guided anterior QLB significantly alleviated the pain during coughing after surgery, shortened the time to first out-of-bed activity and anal flatus, promoting post-operative recovery of the patients undergoing open liver resection.

Salama (2020) stated that adequate pain control after cesarean section (CS) is important to help the newly delivered mothers to feed and care their newborns together with early ambulation of the parturients to avoid the risk of thrombo-embolism and development of chronic abdominal and pelvic pain. In a RCT, these investigators compared the efficacy of QLB and intra-thecal morphine for post-operative analgesia after CS. A total of 90 pregnant women with a gestation of 37 weeks or more scheduled for elective CS were enrolled in this study. All subjects received spinal anesthesia, and after surgery, QLB was performed. They were randomly allocated to control group (CG, 0.1-ml saline added to spinal drug and 24-ml saline for QLB), intra-thecal morphine group (ITM, 0.1-mg morphine added to spinal drug and 24-ml saline for QLB), or QLB group (0.1-ml saline added to spinal drug and 24-ml 0.375 % ropivacaine for QLB). Integrated Analgesia Score (IAS), NRS at rest and during movement, morphine requirements in the first 48 hours, time to first morphine dose, time to first ambulation, and morphine related side effects were recorded. IAS and NRS scores at rest and during movements were significantly less in QLB and ITM than CG. Moreover, QLB had lower IAS and NRS scores at rest and during movements in comparison to ITM. Time to first morphine dose was significantly longer in QLB than in ITM and CG. Also, morphine requirements in the first 48 hours was significantly lower in QLB than ITM and CG (18.2 ± 9.6 mg in QLB versus and 42.8 ± 10.4 mg and 61 ± 12.9 mg in ITM and CG, respectively) (p = 0.001). No significant difference between the 3 groups regarding time to first ambulation (13.4 ± 1.8 hours in QLB versus 11.7 ± 1.9 hours in CG and 12.9 ± 1.6 hours in ITM). Incidence of morphine related side effects was significantly higher in ITM compared to CG and QLB. The authors concluded that QLB and intra-thecal morphine were effective analgesic regimens after CS. However, QLB provided better long lasting analgesia together with reduction of total post-operative morphine consumption.

Sato (2019) noted that US-guided QLB is a regional anesthetic technique that can provide peri-operative analgesia for all age groups, including pediatric patients undergoing abdominal surgery. This researcher hypothesized that the QLB would be as effective as a caudal block, the gold standard of pediatric lower abdominal regional anesthesia, in providing pain control after ureteral re-implantation but also have a longer duration. A total of 47 pediatric patients aged f 1 to 17 years undergoing bilateral ureteral re-implantation surgery via a low transverse incision were enrolled and randomized into the QLB and caudal block groups. All blocks were performed pre-operatively under general anesthesia. This investigator analyzed the following outcomes: the requirement for narcotic analgesics, pain score, episodes of emesis, and complications at 0, 4, 24, and 48 hours post-operatively. The study included 44 patients after excluding 3 who were ineligible. The fentanyl requirement for post-operative rescue analgesia during the first 24 hours was significantly lower in the QLB group than in the caudal block group (median [interquartile range (IQR)]: 0 [0 to 1] versus 3 [0 to 5], p = 0.016, 95 % confidence intervals (CI): -4 to 0); but not at 30 mins, 4 hours or 48 hours. No significant difference was observed in the pain scores or the incidence of interventions to treat nausea and vomiting during the entire period. No post-operative complication was observed. The author concluded that QLB was more effective in reducing the post-operative opioid requirement for rescue analgesia during the initial 24 hours than caudal ropivacaine/morphine.

Scapular Thoracic Bursitis Injection

Osias et al (2018) noted that symptomatic scapulothoracic disorders, including scapulothoracic crepitus and scapulothoracic bursitis are uncommon disorders involving the scapulothoracic articulation that have the potential to cause significant patient morbidity. Scapulothoracic crepitus is the presence of a grinding or popping sound with movement of the scapula that may or may not be symptomatic, while scapulothoracic bursitis refers to inflammation of bursa within the scapulothoracic articulation. Both entities may occur either concomitantly or independently. Nonetheless, the constellation of symptoms manifested by both entities has been referred to as the snapping scapula syndrome. Various causes of scapulothoracic crepitus include bursitis, variable scapular morphology, post-surgical or post-traumatic changes, osseous and soft tissue masses, scapular dyskinesis, and postural defects. Imaging is an important adjunct to the physical examination for accurate diagnosis and appropriate treatment management. Non-operative management such as physical therapy and local injection can be effective for symptoms secondary to scapular dyskinesis or benign, non-osseous lesions. Surgical treatment is utilized for osseous lesions, or if non-operative management for bursitis has failed. Open, arthroscopic, or combined methods have been performed with good clinical outcomes.

Walter et al (2019) stated scapulothoracic pain is a common ailment, but the underlying cause can be difficult to diagnose in a timely manner, and treatment options are limited. These researchers retrospectively reviewed their experience using US-guided therapeutic scapulothoracic interval steroid injections to treat scapulothoracic pain and reviewed correlative MRI findings over a 5-year period. Although a variety of structural causes are known to cause scapulothoracic pain, in the authors’ experience, most cases lacked correlative imaging findings. The authors concluded that US-guided scapulothoracic interval injections provided a safe, easily performed diagnostic and therapeutic tool for treating patients with periscapular pain, providing at least short-term symptom relief.

Sciatic Nerve Block

An UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019a) states that "The sciatic nerve block provides complete anesthesia of the leg below the knee, with the exception of a strip of medial skin innervated by the saphenous nerve. Combined with femoral or saphenous nerve block, it provides analgesia for surgery of the distal anterior thigh; anterior knee; and lateral calf, ankle, or foot. The sciatic nerve block can be performed using either an anterior or a posterior approach, with similar success rates for surgery below the knee … Ultrasound-guided sciatic block – For an ultrasound-guided sciatic block, the ultrasound transducer is held transverse to the course of the nerve. The sciatic nerve can be blocked via a transgluteal (needle inserted just distal and deep to gluteus maximus muscle) or infragluteal (just below the level of the subgluteal crease) approach. For both approaches, the patient is placed in a position between lateral decubitus and prone, with the hip and knee flexed".

Serratus Plane Block for the Management of Post-Operative Pain Following Breast Surgery or Thoracotomy

Madabushi et al (2015) noted that pain following thoracotomy is of moderate-to-severe nature. Management of thoracotomy pain is a challenging task. Post-thoracotomy pain has acute effects in the post-operative period by affecting respiratory mechanics, which increases the morbidity. Poorly controlled thoracotomy pain in the acute phase may also lead to the development of a chronic pain syndrome. A young male patient underwent esophagectomy and esophago-gastric anastomosis for corrosive stricture of the esophagus. Epidural analgesia is standard of care for patients undergoing thoracotomy. Due to hypotension and fluid losses following surgery, he was maintained on intravenous sedato-analgesia during post-operative mechanical ventilation. The thoracic epidural catheter that was placed pre-operatively, had developed blockage during the hospital stay. However, during weaning from ventilation and sedation, he indicated severe pain in the thoracotomy incision. The pain was severe enough to impair tidal breathing. These researchers wanted to examine the efficacy of the serratus anterior plane (SAP) block in the management of thoracotomy pain. The usefulness of SAP block has been discussed in the management of pain of rib fractures and breast surgeries. Despite the hypothesis of its usefulness in causing anesthesia of the hemithorax, there are no available reports of clinical use for pain relief following thoracotomy. These investigators performed the SAP block under ultrasound (US) guidance and placed a catheter for continuous infusion of local anesthetics and opioid. The patient had significant pain relief following a single bolus of the drug. The infusion was started thereafter, which provided excellent analgesia and facilitated an uneventful recovery. The authors described the successful management of thoracotomy pain using the SAP block.

Ohgoshi et al (2015) noted that serratus-intercostal plane block (SIPB) is a novel US-guided thoracic wall nerve block reported recently. These researchers performed SIPB for peri-operative analgesia together with general anesthesia in patients undergoing partial mastectomy. They chose the patients with breast cancer of upper to lower lateral quadrant or subareolar region. Subjects received general anesthesia followed by US-guided SIPB. The needle was introduced in the mid-axillary line at the level of the fourth or fifth rib. Under continuous US guidance, these investigators injected 30-ml of ropivacaine 0.375 to 0.5 % between the serratus anterior and the external intercostal muscles. After the partial mastectomy, the area of sensory loss obtained by skin prick was extended from 5 to 6 as the number of intercostal spaces. Analgesic effect was obtained for 12 to 24 hours. The cephalad dermatomal paresthesia was T2. More than 20 patients received SIPB, and no one acquired the sensory loss at T1 of dermatomal distribution. The authors concluded that SIPB provided effective analgesia for breast surgery of upper to lower lateral quadrant and/or subareolar region. However, it should be administered with other additional analgesic agents when axillary dissection was performed, because sensory loss of T1 was difficult to achieve.

Khalil et al (2017) stated that thoracotomy is one of the most painful surgical procedures. In a prospective, randomized, observer-blinded, controlled study, these researchers examined the safety and effectiveness of US-guided SAPB compared with thoracic epidural analgesia (TEA) for controlling acute thoracotomy pain. The study was performed as a single-institution study in the National Cancer Institute, Cairo University, Egypt. All participants were cancer patients scheduled for thoracotomy. This trial was conducted from February to December 2015. A total of 40 patients scheduled for thoracotomy under general anesthesia were allocated randomly into 1 of 2 groups with 20 patients each; SAPB was performed before extubation with an injection of 30 ml of 0.25 % levobupivacaine followed by 5 ml/hour of 0.125 % levobupivacaine. In the TEA group, thoracic epidural catheters were inserted pre-operatively to be activated before extubation using a lower dose regimen to the SAPB group. Heart rate (HR), mean arterial pressure (MAP), and the visual analog pain score (VAS) measurements were recorded for 24 hours. Rescue analgesia using IV morphine, 0.1 ml/kg, was administered if the VAS was greater than 3. Compared with pre-operative values, the MAP in the SAPB group did not change significantly (p = 0.181), whereas it decreased significantly (p = 0.006) in the TEA group; VAS scores and the total dose of morphine consumed were comparable in the 2 groups. The authors concluded that SAPB appeared to be a safe and effective alternative for post-operative analgesia after thoracotomy. This study did not compare US-guidance versus no US-guidance.

Sir et al (2019) noted that SAPB has been used for pain management during the acute period of conditions affecting the thorax, such as post-thoracotomy recovery, rib fracture, and breast surgery recovery. These investigators reported the use of SAPB in post-traumatic chronic pain treatment. They e described a case of post-traumatic chronic intercostal neuralgia, in which successful pain relief was achieved via repeated injections of local anesthetic and steroid combinations in the serratus anterior plane under US-guidance. The authors concluded that this novel technique was easy to administer, reliable, and warrants further investigation with regard to its use for rehabilitation of patients who are suffering from post-traumatic chronic neuropathies of the chest wall.

Vig et al (2019) noted that post-thoracotomy pain is one of the most severe forms of post-operative pain. Anesthetists usually manage post-thoracotomy pain with an epidural or para-vertebral block. However, both of these techniques have their limitations; US-guided inter-fascial plane block like SAPB is a new concept and is proposed to provide analgesia to the hemithorax. These investigators reported their experience with 10 thoracotomy cases where this block was used as a post-operative analgesic technique. Patients undergoing pulmonary metastasectomy or lobectomy received US-guided SAPB between the serratus anterior and the external intercostal muscles with 0.25 % ropivacaine, and a catheter was inserted. Post-operatively, 0.125 % ropivacaine with fentanyl (1 ug/ml) was given as infusion at 5 to7 ml/hour. Other analgesics were paracetamol and diclofenac. Fentanyl infusion at 0.25 ug/kg/hour was the rescue analgesic if pain persisted; 4 out of 10 patients required fentanyl infusion. Uncontrolled pain in 2 of these patients was at the intercostal drain site; in the third patient, 2 ribs were resected; and in the fourth patient, there was poor drug spread and the catheter could not be placed in the desired plane due to poor muscle mass. The catheter was kept in-situ for a minimum of 48 hours to a maximum of 6 days after surgery. The authors concluded that SAPB could be an attractive option for post-thoracotomy analgesia.; further studies can take the help of the surgeon for catheter placement in the desired plane at the time of wound closure to ensure adequate drug spread.

In a prospective, randomized, single-blind study, Kaushal et al (2019) compared the relative efficacy of US-guided SAPB, pectoral nerves (Pecs) II block, and intercostal nerve block (ICNB) for the management of post-thoracotomy pain in pediatric cardiac surgery. This trial was conducted in a single-institution tertiary referral cardiac center, and comprised 108 children with congenital heart disease requiring surgery through a thoracotomy. Children were allocated randomly to 1 of the 3 groups: SAPB, Pecs II, or ICNB. All participants received 3 mg/kg of 0.2 % ropivacaine for US-guided block after induction of anesthesia. Post-operatively, IV paracetamol was used for multi-modal and fentanyl was used for rescue analgesia. A modified objective pain score (MOPS) was evaluated at 1, 2, 4, 6, 8, 10, and 12 hours post-extubation. The early mean MOPS at 1, 2, and 4 hours was similar in the 3 groups. The late mean MOPS was significantly lower in the SAPB group compared with that of the ICNB group (p < 0.001). The Pecs II group also had a lower MOPS compared with the ICNB group at 6, 8, and 10 hours (p < 0.001), but the MOPS was comparable at hour 12 (p = 0.301). The requirement for rescue fentanyl was significantly higher in ICNB group in contrast to the SAPB and Pecs II groups. The authors concluded that SAPB and Pecs II fascial plane blocks were equally efficacious in post-thoracotomy pain management compared with ICNB, but they had the additional benefit of being longer lasting and were as easily performed as the traditional ICNB. This study did not compare US-guidance versus no US-guidance.

Southgate and Herbst (2019) stated that approximately 10 % of injured patients presenting to the emergency department (ED) are found to have rib fractures. Rib fractures are associated with significant morbidity and mortality, especially in the elderly. Pulmonary complications, including pneumonia, often become apparent 2 to 3 days after injury, when respiratory function is compromised, secondary to pain. Thus, effective analgesia is an important component of rib fracture management; IV opioids are a mainstay of treatment but have side effects including respiratory depression, depressed cough reflex, and delirium in the elderly. The US-guided SAPB is an alternative that has become popular due to its efficacy, relative ease, and limited side-effect profile.

Wang et al (2019) stated that reports of post-operative pain treatment after uni-portal video-assisted thoracoscopic surgery (VATS) are limited. Thoracic para-vertebral block and SAPB have been described recently in pain management after thoracic surgery. A comparison between these 2 blocks for post-operative analgesia after uni-portal VATS has not been previously reported. In a retrospective, propensity-matched study, these researchers compared the analgesic benefits of SAPB and thoracic para-vertebral block after uni-portal VATS and examined the 2 block types for non-inferiority. From December 2015 to May 2018, a total of 636 relevant records of patients who underwent uni-portal VATS under general anesthesia alone or with the addition of SAPB or thoracic para-vertebral block performed pre-operatively were identified. A propensity-matched analysis incorporating pre-operative variables was used to compare the efficacy of post-operative analgesia in 3 groups. A total of 123 patients were identified for analysis. Propensity score matching resulted in 41 patients in each group. The VAS scores were significantly lower in the SAPB group and the thoracic para-vertebral block group than in the control group at the first, second, fourth, and sixth post-operative hours. Cumulative opioid consumption was significantly lower in the SAPB and thoracic para-vertebral block groups than in the control group at 6 hours (18.3 ± 3.1 mg, 18.7 ± 3.9 mg versus 21.5 ± 4.4 mg; p = 0.001) and 24 hours (43.4 ± 7.3 mg, 42.5 ± 7.7 mg versus 49.3 ± 8.8 mg; p < 0.001) post-operatively. The SAPB group was non-inferior to the thoracic para-vertebral block group on pain score and opioid consumption. The authors concluded that the findings of this study suggested that in patients undergoing uni-polar VATS, the addition of single-injection SAPB or thoracic para-vertebral block was associated with early analgesic benefits, including a reduction in post-operative opioid consumption and VAS score. These researchers stated that SAPB was as effective as thoracic para-vertebral block in reducing post-operative pain. Compared to thoracic para-vertebral block, SAPB is advantageous due to its relative ease of application. Moreover, they stated that although SAP block could be an effective therapeutic option for post-operative uni-polar VATS analgesia, further prospective, large-scale, randomized controlled trials are needed to examine the efficacy of and indications for SAPB.

In a randomized controlled trial, Reyad et al (2020) examined US-guided SAPB versus patient-controlled analgesia (PCA) on the emergence of post-thoracotomy pain syndrome (PTPS) after thoracotomies for thoracic tumors. This trial included 89 patients with chest malignancies, scheduled for thoracotomy were randomly allocated into 2 groups: Group A "PCA-group; n = 44" receiving patient-controlled analgesia; and group B "SAPB group; n = 45" where analgesia was provided by SAPB. The primary outcome measure was the assessment for the possible emergence of PTPS at 12 weeks. The secondary outcome measures were pain relief measured using VAS score. Quality of life (QOL) was assessed using Flanagan QOL Scale (QOLS) and activity level was assessed using Barthel Activity of daily living (ADL) score. At week 8, PTPS incidence was significantly (p = 0.037) higher in the PCA group (45 %) than in the SAPB group (24 %) with a relative risk (RR) of 1.38 and 95 % confidence interval (CI): 1.01 to 1.9; while the incidence of PTPS at week 12 was significantly (p = 0.035) higher in the PCA group (43 %) than in the SAPB group (22 %) with a RR of 2.38 and 95 % CI: 1.23 to 4.57. The need for pain therapy in PTPS patients was significantly lower in the SAPB group (17.7 %) than the PCA group (38.6 %) (p = 0.028) at week 12. Pain intensity: VAS-R and VAS-D (pain scores at rest and with activity, respectively) was comparable (p > 0.05) between both groups at 6, 12, 18 and 24 hours, however VAS was significantly higher in the PCA group at week 8 (p = 0.046) and week 12 (p = 0.032). Both groups were comparable regarding ADL and QOL scores (p > 0.05). The authors concluded that SAPB is assumed to be a good alternative for post-thoracotomy analgesia following thoracotomies. The current work hypothesized that SAPB for a week post-operatively, may reduce the emergence of PTPS and may reduce the demand for pain therapy in those patients.

Hanley et al (2020) stated that the deep SAPB is a promising novel regional anesthesia technique for blockade of the antero-lateral chest wall. Evidence for the efficacy of SAPB versus other analgesic techniques in thoracic surgery remains inadequate. In a randomized, double-blinded, single-center, non-inferiority study, these researchers compared US-guided continuous SAPB with a surgically placed continuous thoracic para-vertebral block (SPVB) technique in patients undergoing VATS. These investigators allocated 40 patients undergoing VATS to either SAPB or SPVB, with both groups receiving otherwise standardized treatment, including multi-modal analgesia. The primary outcome was 48-hour opioid consumption; secondary outcomes included numerical rating scale (NRS) for post-operative pain, patient-reported worst pain score (WPS) as well as functional measures (including mobilization distance and cough strength). A 48-hour opioid consumption for the SAPB group was non-inferior compared with SPVB. SAPB was associated with improved NRS pain scores at rest, with cough and with movement at 24 hours post-operatively (p = 0.007, p = 0.001 and p = 0.012, respectively). SAPB was also associated with a lower WPS (p = 0.008). Day 1 walking distance was improved in the SAPB group (p = 0.012), whereas the difference in cough strength did not reach statistical significance (p = 0.071). There was no difference in hemodynamics, opioid side effects, length of hospital stay or patient satisfaction between the 2 groups. The authors concluded that SAPB, as part of a multi-modal analgesia regimen, was non-inferior in terms of 48-hour opioid consumption compared to SPVB and was associated with improved functional measures in thoracic surgical patients.

Furthermore, an UpToDate review on "Thoracic nerve block techniques" (Rosenblatt and Lai, 2020b) states that "Thoracic interfascial plane blocks include the Pecs I, Pecs II, serratus plane (SP), transversus thoracic muscle plane (TTMP), and erector spinae (ESP) blocks. These blocks can be utilized for superficial and deep surgery in the chest wall and axillary regions (e.g., mastectomy, cosmetic breast surgery, chest tube placement, multiple rib fractures). We suggest the use of ultrasound guidance for TPVB and the interfascial plane blocks of the chest (Grade 2C), to increase the success rate and reduce complications". It also states that "The SP block is designed to anesthetize the thoracic intercostal nerves in order to provide analgesia for the lateral chest wall. Intercostal nerves from T2 to T9 are usually blocked. The SP block is a more posterior and lateral modification of the Pecs II block; they are not performed together. However, the Pecs I injection must be added to the SP block for breast reconstruction or surgery that violates the anterior chest wall, to block the medial and lateral pectoral nerves. The SP block is performed using ultrasound guidance".

Supraclavicular Nerve Block for Post-Operative Pain Control

Karaman et al (2019) compared the effects of supraclavicular brachial plexus block (SCBPB) with ISBPB in terms of post-operative pain and quality of recovery after ASS. A total of 62 adult patients scheduled for ASS under general anesthesia were randomized into 2 groups to receive either ISBPB (IB group, n = 31) or SCBPB (SB group, n = 29) with 20-ml of 0.25 % bupivacaine under US guidance. Assessments included post-operative pain scores, additional analgesic requirement, timing of the first analgesic requirement, quality of recovery-40 (QoR-40) scores, block characteristics, and side effects. No significant differences were found between the 2 groups for pain scores (p = 0.34), timing of first analgesic requirement (p = 0.30), additional analgesic requirement (p = 0.34), or QoR-40 (p = 0.13) scores. The block characteristics regarding procedure time (p = 0.95), block failure, and onset time of sensory blockade (p = 0.33) were similar. Horner's syndrome occurred in 8 patients in the ISBPB group and 1 patient in the SCBPB group (p = 0.015). The authors concluded that this study showed that US-guided SCBPB was as effective as ISBPB in reducing post-operative pain and improving the quality of recovery for ASS.

Furthermore, an UpToDate review on "Upper extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019b) states that "The supraclavicular approach blocks the brachial plexus at the level of the nerve trunks (upper, middle, and lower), where the nerves are packed closely together. Supraclavicular block provides a reliable, rapid onset and dense block for surgery of the distal two-thirds of the upper extremity, including those surgeries requiring an upper extremity tourniquet (e.g., hand surgery) … Ultrasound-guided supraclavicular block – We suggest the use of ultrasound guidance whenever a supraclavicular block is performed in order to minimize the chance of vascular puncture and pneumothorax. The ultrasound transducer is placed in a transverse position parallel to and just above the clavicle. The subclavian artery is identified by moving the transducer medially along the clavicle and directing the transducer toward the first rib. The brachial plexus at the level of the trunks and divisions appears as a "bundle of grapes" lateral to the subclavian artery. The lateral end of the transducer is often rotated slightly cephalad to visualize the brachial plexus in a more short-axis plane (perpendicular to its path). The needle is inserted in-plane from lateral to medial (parallel to the transducer), with the target being the junction of the subclavian artery, brachial plexus, and first rib ("corner pocket") and LA is injected to lift the brachial plexus off the first rib. Twenty to 30 mL of LA is injected, after negative aspiration for blood, in 5-mL increments, while looking for spread around the nerves. Most practitioners prefer a two-injection technique, with one-half of the LA deposited at the "corner pocket" and the other one-half deposited more superficially between trunks of the plexus or above the plexus. Injection should be stopped if the patient experiences pain or paresthesia".

Transverse Abdominis Plane (TAP)-Block for the Management of Post-Operative Pain following Abdominal Surgery

Wang et al (2016) stated that US-guided ilio-inguinal/ilio-hypogastric (II/IH) nerve and transversus abdominis plane (TAP) blocks have been increasingly utilized in patients for peri-operative analgesia. In a meta-analysis, these researchers examined the clinical efficacy of US-guided II/IH nerve or TAP blocks for peri-operative analgesia in patients undergoing open inguinal surgery. A systematic search was conducted of 7 data-bases from the inception to March 5, 2015. Randomized controlled trials (RCTs) comparing the clinical efficacy of US-guided versus landmark-based techniques to perform II/IH nerve and TAP blocks in patients with open inguinal surgery were included. These investigators constructed random effects models to pool the standardized mean difference (SMD) for continuous outcomes and the odds ratio (OR) for dichotomized outcomes. Ultrasound-guided II/IH nerve or TAP blocks were associated with a reduced use of intra-operative additional analgesia and a significant reduction of pain scores during day-stay. The use of rescue drugs was also significantly lower in the US-guided group. The authors concluded that the use of US-guidance to perform an II/IH nerve or a TAP block was associated with improved peri-operative analgesia in patients following open inguinal surgery compared to landmark-based methods.

Park et al (2017) stated that TAP block has been used as a component of multi-modal analgesia after abdominal operation. These researchers introduced a new laparoscope-assisted TAP (LTAP) block technique using intra-peritoneal injection and compared its analgesic effect with that of an US-guided TAP (UTAP) block in terms of post-operative pain control. They carried out a prospective, randomized, single-blinded non-inferiority clinical trial with patients undergoing elective laparoscopic colectomy for colon cancer; 80 patients were randomly assigned (1:1 ratio) to the UTAP and LTAP groups. At the end of the operation, opioid consumption and numeric rating scores (NRS; 0 [no pain] to 10 [worst pain]) of pain were recorded at 2, 6, 24, and 48 hours post-operatively and were compared between the groups. The primary end-point was pain NRS during rest at 24 hours after operation. A total of 38 patients in the LTAP group and 35 patients in the UTAP group completed the study protocol. These investigators found no significant difference in mean ± SD pain NRS during rest at 24 hours between the LTAP group (3.90 ± 1.7) and the UTAP group (4.5 ± 1.9). The mean difference (MD) in pain NRS during rest at 24 hours was 0.57 (95 % confidence interval [CI]: -0.26 to 1.41). Because the lower boundary of a 95 % CI for the differences in pain NRS was greater than -1, non-inferiority was established. There was no significant difference between the groups in NRS pain during rest, NRS pain on movement, and post-operative morphine consumption during the 48 hours after operation. The authors concluded that these findings demonstrated that their new LTAP block technique was non-inferior to the US-guided technique in providing a TAP block after laparoscopic colorectal operation.

Kim et al (2017) stated that the concepts of enhanced recovery after surgery (ERAS) have steadily increased in usage, with benefits in patient outcomes and hospital length of stay (LOS). One important component of successful implementation of ERAS protocol is optimized pain control, via the multi-modal approach, which includes neuraxial or regional anesthesia techniques and reduction of opioid use as the primary analgesic; and TAP block is one such regional anesthesia technique, and it has been widely studied in abdominal surgery. These investigators conducted a literature search in Medline and PubMed, and reviewed the benefits of TAP blocks for colorectal surgery, both laparoscopic and open. They organized the data by surgery type, by method of TAP block performance, and by a comparison of TAP block to alternative analgesic techniques or to placebo. These researchers examined different end-points, such as post-operative pain, analgesic use, return of bowel function, and LOS. The majority of studies examined TAP blocks in the context of laparoscopic colorectal surgery, with many, but not all, demonstrating significantly less use of post-operative opioids in comparison to placebo, wound infiltration, and standard post-operative patient-controlled analgesia (PCA) with intravenous opioid administration. There was evidence that use of liposomal bupivacaine may be more effective than conventional long-acting local anesthetics. Non-inferiority of TAP infusions has been demonstrated, compared with continuous thoracic epidural infusions. The authors concluded that TAP blocks were easily performed, cost-effective, and an opioid-sparing adjunct for laparoscopic colorectal surgery, with minimal procedure-related morbidity. The evidence was in concordance with several of the goals of ERAS pathways. Moreover, this review did not mention the use of US-guidance for TAP block.

Doble et al (2018) stated that TAP blockade with long-acting anesthetic can be used during open ventral hernia repair (VHR) with posterior component separation (PCS). TAP block can be performed under US guidance (US-TAP) or under direct visualization (DV-TAP). These researchers hypothesized that US-TAP and DV-TAP provide equivalent post-operative analgesia following open VHR. They carried out a retrospective review of patients undergoing open VHR with PCS who received TAP blocks with 266-mg of liposomal bupivacaine. Data included demographics, co-morbidities, LOS, average post-operative day (POD) pain scores, and narcotic requirements (normalized to mg oral morphine). Statistical analysis utilized Student's t test and Fisher's exact test. A total of 39 patients were identified (22 DV-TAP). There were no differences between the groups with respect to demographics, co-morbidities, pre-operative pain medication usage (narcotic and non-narcotic) or herniorrhaphy-related data. The average POD0 pain score was lower for the DV-TAP group (2.35 versus 4.18; p = 0.019). Narcotic requirements on POD0 (48.0 versus 103.76 mg; p = 0.02), POD1 (128.45 versus 273.82 mg; p = 0.03), POD4 (54.29 versus 160.75 mg; p = 0.042), and during the complete hospitalization (408.52 versus 860.92 mg; p = 0.013) were lower in the DV-TAP group. There were no differences between initiation of diet or LOS. During the study, no changes were made to the VHR enhanced recovery pathway. The authors concluded that DV-TAP blocks appeared to provide superior analgesia in the immediate post-operative period. To achieve similar post-operative pain scores, patients in the US-TAP group required significantly more narcotic administration during their hospitalization. The study highlighted DV-TAP as a valuable addition to VHR recovery pathways.

Kakade and Wagh (2019) noted that TAP block is a fascial plane block providing post-operative analgesia after lower abdominal surgeries including Cesarean section. Conventionally, it is administered under US guidance or by blind technique. These researchers examined a novel trans-peritoneal surgical TAP block for providing safe and effective analgesia after Cesarean section through transverse incision. A total of 100 patients who fulfilled the inclusion criteria were included in the study after obtaining informed written consent. They were randomized in 2 groups: Group A with surgical TAP block and Group B without TAP block as control. Surgical TAP block was administered by trans-peritoneal route before the closure of peritoneum with 0.25 % bupivacaine (dose adjusted with weight of the patient), and VAS was assessed by a blind assessor. Time for rescue analgesia was noted and analyzed with the "2 independent sample t-test". The duration of post-operative analgesia in hours was significantly longer in the TAP block group compared with the control group (5.14 ± 1.63 versus 2.61 ± 0.89, p < 0.001). There was no reported complication of the surgical technique or any adverse effect of the used drug. The authors concluded that surgical TAP block via the trans-peritoneal route is a safe, easy and effective mode of providing post-operative analgesia after Cesarean section. This technique did not need any costly specialist equipment, overcame the technical limitations of US-guided TAP block and could be used in obese patients also. It had almost no side effects, and the technique could be easily mastered.

Vonu et al (2019) stated that there are a variety of regional nerve blocks that have been utilized in abdominoplasty procedures including transversus abdominis plane (TAP), intercostal, rectus sheath (RS), pararectus + II/IH, quadratus lumborum, and paravertebral blocks. No consensus exists regarding the most effective nerve block modality in optimizing post-procedural comfort levels. In a systematic review, these researchers examined the efficacy of the various abdominal nerve blocks used in abdominoplasty surgery, and drew attention to any modality that may be superior in regards to effectiveness and/or administration. Using PRISMA guidelines, a systematic review was performed to identify studies that have used regional nerve blocks in abdominoplasty procedures. Opioid consumption, pain scores, time to ambulation, time in the recovery room, and time to first analgesia request were extracted when available. A total of 191 articles were reviewed of which 8 met inclusion criteria. The nerve blocks represented included TAP, RS, pararectus + II/IH, intercostal, and quadratus lumborum. All modalities were effective in reducing opioid consumption except quadratus lumborum. The authors concluded that TAP, RS, pararectus + II/IH, and intercostal regional nerve blocks have been shown to optimize post-operative pain management in abdominoplasty procedures. When studied against one another, the existing literature suggested that TAP is more effective than RS and pararectus + II/IH. These researchers noted that when US guidance is unavailable, consideration should be given to TAP using the direct visualization approach.

Wong et al (2020) noted that TAP block is an important non-narcotic adjunct for post-operative pain control in abdominal surgery. Surgeons can use LTAP, however, direct comparisons to conventional UTAPs have been lacking. In a prospective, randomized, patient- and observer-blinded, parallel-arm, non-inferiority trial, these researchers examined if surgeon-placed LTAPs were non-inferior to anesthesia-placed UTAPs for post-operative pain control in laparoscopic colorectal surgery. This study was performed at a single tertiary academic center between 2016 and 2018 on adult patients undergoing laparoscopic colorectal surgery. Narcotic consumption and pain scores were compared for LTAP versus UTAP for 48 hours post-operatively. A total of 60 patients completed the trial (31 UTAP, 29 LTAP) of which 25 patients were women (15 UTAP, 10 LTAP) and the mean ages (SD) were 60.0 (13.6) and 61.5 (14.3) in the UTAP and LTAP groups, respectively. There was no significant difference in post-operative narcotic consumption between UTAP and LTAP at the time of PACU discharge (median inter-quartile range [IQR] milligrams of morphine, 1.8 [0 to 4.5] UTAP versus 0 [0 to 8.7] LTAP; p = 0.32), 6 hours post-operatively (5.4 [1.8 to 17.1] UTAP versus 3.6 [0 to 12.6] LTAP; p = 0.28), at 12 hours post-operatively (9.0 [3.6 to 29.4] UTAP versus 7.2 [0.9 to 22.5] LTAP; p = 0.51), at 24 hours post-operatively (9.0 [3.6 to 29.4] UTAP versus 7.2 [0.9 to 22.5] LTAP; p = 0.63), and 48 hours post-operatively (39.9 [7.5 to 70.2] UTAP versus 22.2 [7.5 to 63.8] LTAP; p = 0.41). Patient-reported pain scores as well as pre-, intra-, and post-operative course were similar between groups. Non-inferiority criteria were met at all post-operative time-points up to and including 24 hours but not at 48 hours. The authors concluded that surgeon-delivered LTAPs were safe, effective, and non-inferior to anesthesia-administered UTAPs in the immediate post-operative period. These investigators stated that this method (surgeon-placed LTAPs) should be considered in all patients undergoing laparoscopic colorectal surgery where an US-guided TAP block is planned.

Furthermore, an UpToDate review on "Abdominal nerve block techniques" (Rosenblatt and Lai, 2020a) states that "We perform TAP blocks with ultrasound guidance, though TAP block was first described using anatomic landmarks. TAP blocks can also be placed under direct vision by the surgeon during laparoscopy or laparotomy … We suggest using ultrasound guidance rather than anatomic landmarks to perform abdominal blocks (Grade 2C) to increase the success rate and reduce complications ".

Ultrasound Guidance: Experimental and Investigational Indications

Botulinum Toxin Injection for the Treatment of Cervical Dystonia

Hong et al (2012) noted that dysphagia is a common side effect after botulinum toxin (BTX) injections for cervical dystonia (CD), with an incidence of 10 to 40 %, depending upon the study and dose used. This study consisted of 5 pre-selected women who met criteria for CD and subsequent dysphagia after electromyography (EMG)-guided injections. Injections were performed with US imaging, and the effects on swallowing were examined. Separately, sternocleidomastoid (SCM) thickness in healthy controls and treated patients was measured. There were 34 episodes of dysphagia over 98 injection sessions using EMG guidance for a cumulative rate of 34.7 %. Using US plus EMG guidance, there was 0 % dysphagia across 27 injection sessions; SCM thickness was less than 1.1 cm. The authors concluded that US combined with EMG guidance eliminated recurrent dysphagia after BTX treatment, possibly by keeping the injectate within the SCM.

Huang et al (2015) examined the efficacy of US-guided local injection of BTX type A (BTX-A) treatment with orthopedic joint brace in patients with CD. A total of 105 patients with CD were selected and randomly divided into medication treatment group (A group), BTX treatment group under US guidance (B group) and BTX under US guidance combined with orthopedic joint brace treatment group (C group). Tsui scale and Spitzer quality of life (QOL) index was used to evaluate the spasm and QOL. The scores of Tsui scale and Spitzer QOL index were compared after US-guided local treatment for 1 month, 3 months and 6 months. The difference in Tsui and Spitzer scores before and after the treatment of oral medications were not statistically significant (p > 0.05). Whereas, the differences in Tsui and Spitzer scores before and after the treatment between local injection of BTX-A treatment group and orthopedic joint brace combined with BTX-A injection group were statistically significant (p < 0.05). Furthermore, the difference in Tsui and Spitzer scores of orthopedic joint brace combined with BTX-A injection group at 3 months, and 6 months were statistically significant compared to local injection of BTX-A treatment group (p < 0.05). The authors concluded that US-guided local injection of BTX-A combined with orthopedic brace could significantly reduce muscle tension and improve QOL. Moreover, US-guidance helped reduce BTX injection amount without affecting the efficacy and ensured that the medicine accurately reached to the site of action with a lower occurrence rate of adverse reactions.

In a systematic review, Grigoriu et al (2015) examined the impact of different injection-guiding techniques on the effectiveness of BTX-A for the treatment of focal spasticity and dystonia. Data sources included Medline via PubMed, Academic Search Premier, PASCAL, the Cochrane Library, Scopus, SpringerLink, Web of Science, EM Premium, and PsycINFO; 2 reviewers independently selected studies based on pre-determined inclusion criteria. Data relating to the aim were extracted. Methodological quality was graded independently by 2 reviewers using the Physiotherapy Evidence Database assessment scale for randomized controlled trials (RCTs) and the Downs and Black evaluation tool for non-RCTs. Level of evidence was determined using the modified Sackett scale. A total of 10 studies were included; 7 were randomized. There was strong evidence (level 1) that instrumented guiding (US, electrical stimulation [ES], EMG) was more effective than manual needle placement for the treatment of spasmodic torticollis, upper limb spasticity, and spastic equinus in patients with stroke, and spastic equinus in children with cerebral palsy (CP); 3 studies provided strong evidence (level 1) of similar effectiveness of US and ES for upper and lower limb spasticity in patients with stroke, and spastic equinus in children with CP, but there was poor evidence or no available evidence for EMG or other instrumented techniques. The authors concluded that these findings strongly recommended instrumented guidance of BTX-A injection for the treatment of spasticity in adults and children (ES or US), and of focal dystonia such as spasmodic torticollis (EMG). No specific recommendations can be made regarding the choice of instrumented guiding technique, except that US appeared to be more effective than ES for spastic equinus in adults with stroke.

Allison and Odderson (2016) reported a case of a young man with idiopathic CD who developed anterocollis (forward flexion of the neck) not responsive to prior scalene and SCM injections. To safely access the deeper cervical musculature, US was used in conjunction with EMG, to inject the longus colli muscles bilaterally. The patient responded well and had no complications. The longus colli has been reported to be injected using EMG, fluoroscopy, computed tomography (CT), and, less frequently, US. The authors proposed that US guidance is an excellent technique for BTX injection, especially for deep cervical muscles such as the longus colli.

Kutschenko et al (2020) examined the correlations of BTX therapy with dysphagia. These researchers studied a group of CD patients with optimized BTX therapy during a prolonged period of time to record their dysphagia frequency, severity and duration; they also assessed potential risk factors and attempted to avoid it by using US guidance for BTX applications. BTX therapy of 75 CD patients (23 men, 52 women, age of 60 ± 12 years, BTX total dose of 303.5 ± 101.5 uMU) was retrospectively analyzed for 1 year. BTX therapy was optimized before the observation period. Dysphagia was noticed by 1/5 of the patients. In those patients, it only occurred in about 1/3 of the injection series. It was never associated with a functional deficit and lasted several days to 2 weeks. It was not related to patient age or gender, BTX total dose, BTX dose in the SCM, BTX dose in the SCM and scalenii muscles, by BX therapy with bilateral SCM injections or BTX therapy with abobotulinumtoxinA. The authors concluded that US guidance was not able to prevent it. These researchers stated that further prospective studies are needed to examine the underlying dystonia associated swallowing abnormalities as a potentially predisposing factor.

Kim et al (2020) stated that US guidance may improve the accuracy of BTX injection, but studies of its potential for CD treatment are lacking. In an observational study, these researchers determined the accuracy of US-guided injection in the SCM; a total of 18 embalmed cadavers were used in this study. In total, 36 SCMs from 18 embalmed cadavers were examined. One physician performed US scans to divide each SCM into quarters and evaluated its cross-sectional area (CSA) and thickness at each of 3 meeting points between adjacent quarters. Under US guidance, another experienced physician injected methylene blue solution at 1 of the 3 points, using the in-plane technique (12 specimens/point; right SCM 3 ml, left SCM 5 ml). One anatomist dissected all cadavers and measured the distance of dye dispersion along the longitudinal axis of each muscle. Dispersion ratio was calculated as longitudinal dye dispersion divided by SCM length. Main outcome measures were SCM thickness and CSA; dye dispersion patterns (dispersion distance and dispersion ratio). SCM thickness and CSA were greatest at the middle injection point (mean ± SD 6.6 ± 2.0 mm and 1.4 ± 0.6 cm2 , respectively). All injections were successful, except in 1 case where the SCM was thin and the dye reached the omohyoid muscle. Mean longitudinal dye dispersion and dispersion ratio were significantly greater when the volume was 5 ml. There were no statistically significant differences in dispersion patterns among the 3 injection points. The authors concluded that US-guided intra-muscular injection could be performed with good accuracy in the SCM, as US could be used to evaluate SCM thickness and CSA. Moreover, these researchers stated that higher volumes of injection solution appeared to diffuse better, but further clinical studies are needed to determine optimal injection volume.

Furthermore, an UpToDate review on "Treatment of dystonia" (Comella, 2020) states that "there is no consensus regarding standard practices for BoNT injections, including dilution ratios for the different BoNT products, the dose per injection, the total dose per muscle, the number of injections at each site, or the methods of targeting injections (e.g., whether guided by vision, electromyography, or ultrasound). All of these parameters vary among practitioners and centers".

Costochondral Injection

Cho and Park (2019) stated that Tietze`s syndrome is an uncommon disease of unknown etiology that manifests as pain and tenderness of the para-sternal joints. To-date, however, there has been no report on US findings concerning swelling of the costochondral joint in Tietze`s syndrome. Moreover, there has been no research investigating images of US-guided corticosteroid injection, although corticosteroid injection is one of the most important treatments for Tietze`s syndrome. These investigators reported a case of Tietze`s syndrome where US images were used in the diagnostic and therapeutic process. A 70-year old man was examined for left chest pain that had lasted for several weeks. Physical examination at the authors’ clinic revealed a focal tenderness of the left third costochondral joint, and ultrasonography showed a swelling of the left third costochondral joint. Considering both the clinical and radiological examinations, the patient received a diagnosis of Tietze`s syndrome with costochondral joint swelling. Then, the patient agreed to an US-guided left third costochondral corticosteroid injection after receiving a detailed explanation of the disease and treatment. After receiving 3 US-guided corticosteroid injections, his chest pain subsided, and the swelling and tenderness also disappeared completely. The authors concluded that the findings of this case suggested that US was important in the diagnosis and treatment of Tietze`s syndrome.

Dorsal Scapular Nerve Block

Harmon and Hearty (2007) described a case report of using real-time, high-resolution ultrasound (US) guidance to facilitate blockade of the suprascapular nerve (SSN). They described a case report and technique for using a portable US scanner (38 mm broadband (13-6 MHz) linear array transducer (SonoSite Micromaxx SonoSite, Inc.) to guide SSN block. The subject was a 44-year old man who presented with severe, painful osteoarthritis with adhesive capsulitis of his right shoulder. The US transducer in a transverse orientation was placed over the scapular spine. Moving the transducer cephalad the suprascapular fossa was identified. While imaging the supraspinatus muscle and the bony fossa underneath, the US transducer was moved laterally (maintaining a transverse transducer orientation) to locate the suprascapular notch. The SSN was seen as a round hyperechoic structure at 4-cm depth beneath the transverse scapular ligament in the scapular notch. The nerve had an approximate diameter of 200 mm. Real-time imaging was used to direct injection in the scapular notch; US scanning confirmed local anesthetic spread. The patient's pain intensity decreased; shoulder movement and function improved. These improvements were maintained at 12 weeks. The authors concluded that US guidance did not expose patients and personnel to radiation. It was also less expensive than other imaging modalities. This technique has applications in both acute and chronic pain management.

Borglum et al (2011) presented a case with an US-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the SSN. The patient suffered from a severe and very painful adhesive capsulitis of the left shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low impact passive and guided active mobilization by the performing physiotherapist for 3 consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlighted the possibility of a USG continuous nerve block of the SSN as sufficient pain management in the immediate post-operative period following capsular release of the shoulder. Findings in other painful shoulder conditions and suggestions for future studies were discussed in the text.

Laumonerie et al (2019a) noted that a bone landmark-based approach (LBA) to the distal SSN (dSSN) block is an attractive "low-tech" method available to physicians with no advanced training in regional anesthesia or US guidance. The primary aim of this study was to validate the feasibility of an LBA to blockade of the dSSN by orthopedic surgeons using anatomic analysis. The secondary aim was to describe the anatomic features of the sensory branches of the dSSN. An LBA was performed in 15 cadaver shoulders by an orthopedic resident. Then, 10 ml of methylene blue-infused 0.75 % ropivacaine was injected around the dSSN; 2.5ml of red latex solution was also injected to identify the position of the needle tip. The division and distribution of the sensory branches that originate from the SSN were described. The median distance between the dSSN and the site of injection was 1.5 cm (0 to 4.5 cm). The most common injection site was at the proximal third of the scapular neck (n = 8); 15 dSSNs were stained proximal to the origin of the most proximal sensory branch. All 15 dSSNs gave off 3 sensory branches that innervated the posterior glenohumeral capsule, the subacromial bursa, and the coraco-clavicular and acromio-clavicular ligaments. The authors concluded that an LBA for anesthetic blockade of the dSSN by an orthopedic surgeon was a simple, reliable, and accurate method. Injection close to the suprascapular notch was recommended to involve the dSSN proximally and its 3 sensory branches.

Laumonerie et al (2019b) compared the accuracy of dSSN blockade performed with the use of US-guided regional anesthesia (USRA) versus with a LBA. A secondary aim was to describe the anatomic features of the sensory branches of the dSSN. USRA and LBA were performed in 15 shoulders each from 15 cadavers (total of 30 shoulders). Then, 10-ml of methylene blue-infused ropivacaine 0.75 % was injected into the dSSN. Simultaneously, 2.5-ml red latex solution was injected to identify the position of the needle tip. The division and distribution of the sensory branches originating from the SSN were described. The tip of the needle was identified at 1.3 cm (range of 0 to 5.2 cm) and 1.5 cm (range of 0 to 4.5 cm) with USRA and the LBA, respectively (p = 0.90). Staining diffused past the origin of the most proximal sensory branch in 27 cases. The most proximal sensory branch arose 2.5 cm from the suprascapular notch. Among the 3 failures that occurred in the USRA group, the sensory branches also failed to be marked. All 30 dSSNs gave off 3 sensory branches, which innervated the posterior glenohumeral capsule, the subacromial bursa, and the coraco-clavicular and acromio-clavicular ligaments. An LBA was as reliable and accurate as USG for anesthetic blockade of the dSSN. Marking of the SSN must be proximal to the suprascapular notch to involve the 3 sensory branches in the anesthetic blockade. The authors concluded that the present study demonstrated that a LBA to anesthetic blockade of the dSSN was accurate and can be performed by orthopedic surgeons lacking experience in USG anesthetic techniques.

Gluteal Nerve Injection

In a cadaveric study, Finnoff et al (2008) compared the accuracy of ultrasound (US)-guided piriformis injections with fluoroscopically-guided contrast-controlled piriformis injections. A total of 20 piriformis muscles in 10 un-embalmed cadavers were injected with liquid latex using both fluoroscopically-guided contrast-controlled and US-guided injection techniques. All injections were performed by the same experienced individual. Two different colors of liquid latex were used to differentiate injection placement for each procedure, and the injection order was randomized. The gluteal regions were subsequently dissected by an individual blinded to the injection technique. Colored latex observed within the piriformis muscle, sheath, or both was considered an accurate injection; 19 of 20 US-guided injections (95 %) correctly placed the liquid latex within the piriformis muscle, whereas only 6 of the 20 fluoroscopically-guided contrast-controlled injections (30 %) were accurate (p = 0.001). The liquid latex in 13 of the 14 missed fluoroscopically-guided contrast-controlled piriformis injections and the single missed US-guided injection was found within the gluteus maximus muscle. In the single remaining missed fluoroscopically-guided contrast-controlled piriformis injection, the liquid latex was found within the sciatic nerve. The authors concluded that in this cadaveric model, US-guided piriformis injections were significantly more accurate than fluoroscopically-guided contrast-controlled injections. Despite the use of bony landmarks and contrast, most of the fluoroscopically attempted piriformis injections were placed superficially within the gluteus maximus. Clinicians performing piriformis injections should be aware of the potential pitfalls of fluoroscopically-guided contrast-controlled piriformis injections and consider using US guidance to ensure correct needle placement.

Smith et al (2012) described and validated US-guided techniques for injecting the obturator internus (OI) muscle or bursa using a cadaveric model. A single experienced operator completed 10 US-guided OI injections in 5 un-embalmed cadaveric pelvis specimens (4 female and 1 male, aged 71 to 89 years with body mass indices (BMI) of 15.5 to 24.2 kg/m2); 4 different techniques were used:

OI tendon sheath (4 injections),
OI intra-muscular (2 injections),
OI bursa trans-tendinous (2 injections), and
OI bursa short-axis (2 injections).

In each case, the operator injected 1.5-ml of diluted yellow latex using direct US guidance and a 22-G, 87.5-mm (3.5-in) needle; 72 hours later, study co-investigators dissected each specimen to examine injectate placement. All 10 OI region injections accurately placed latex into the primary target site; 2 of the 4 OI tendon sheath injections produced overflow into the underlying OI bursa. Both OI intra-muscular injections delivered 100 % of the latex within the OI. All 4 OI bursa injections (2 trans-tendinous and 2 short-axis) delivered 100 % of the latex into the OI bursa, with the exception that 1 OI bursa trans-tendinous injection produced minimal overflow into the OI itself. No injection resulted in injury to the sciatic nerve or gluteal arteries, and no injectate overflow occurred outside the confines of the OI or its bursa. The authors concluded that the results of this study showed that US-guided injections into the OI or its bursa were feasible and, thus, may play a role in the diagnosis and management of patients presenting with gluteal and "retro-trochanteric" pain syndromes.

Dillow et al (2013) stated that the para-sacral (PS) approach to sciatic nerve blockade has the potential for safe and effective use in children, but has never been studied in this population. Its potential advantages include increased posterior cutaneous nerve block reliability, potential for hip joint analgesia, and decreased nerve depth, making US guidance easier. These researchers examined the efficacy of an US-guided PS sciatic nerve block in children. A total of 19 patients, aged 1 to 16 years, scheduled for lower limb surgery with peripheral nerve blockade (PNB) were prospectively enrolled. A PS sciatic block was performed using both US guidance and nerve stimulation, and 0.5 ml/kg ropivacaine 0.2 % (maximum 20 ml) was administered. Patient demographics, the time to perform the block, the lowest intensity of nerve stimulation, evoked response, identification of gluteal arteries, and amount of narcotic given were recorded. Post-operatively, pain scores, block success or failure, block duration, and complications were recorded. The block was performed using the PS approach in 95 % of the cases. The success rate was 100 % in the PS sciatic blocks performed. The pain scores for all patients in the first post-surgical hour were 0, except 1 patient that had a pain score of 3 of 10 at 30 mins; his pain improved to 0 of 10 after administration of 1 dose of fentanyl and distraction techniques. The blocks lasted 17.3 ± 5.4 hours. No complications were identified. The authors concluded that the PS approach was an effective option for sciatic nerve blockade to provide post-operative pain relief in children having lower extremity surgery.

Iliopsoas Bursa Injection

Blaichman et al (2020) noted that hip pain is a commonly reported primary symptom with many potential causes. The causal entity can remain elusive, even after clinical history review, physical examination, and diagnostic imaging. Although there are many options for definitive treatment, many of these procedures are invasive, are associated with risk of morbidity, and can be unsuccessful, with lengthy revision surgery required. Percutaneous musculoskeletal intervention is an attractive alternative to more invasive procedures and an indispensable tool for evaluating and managing hip pain. Ultrasonography (US) is an ideal modality for imaging guidance owing to its low cost, portability, lack of ionizing radiation, and capability for real-time visualization of soft-tissue and bone structures during intervention. These investigators evaluated both common and advanced US-guided procedures involving the pelvis and hip, including anesthetic and corticosteroid injections, percutaneous viscosupplementation, platelet-rich plasma (PRP) injection to promote tendon healing, and micro-wave ablation (MWA) for neurolysis. In addition, specific anatomic structures implicated in hip pain were discussed and included the hip joint, iliopsoas bursa, ilio-inguinal nerve, lateral femoral cutaneous nerve, greater trochanteric bursa, ilio-tibial band, ischio-gluteal bursa, hamstring tendon origin, piriformis muscle, and quadratus femoris muscle. The relevant US-depicted anatomy and principles underlying technically successful interventions also were discussed. Familiarity with these techniques could aid radiologists in assuming an important role in the care of patients with hip pain.

Furthermore, an UpToDate review on "Musculoskeletal ultrasonography: Guided injection and aspiration of joints and related structures" (Bruyn, 2020) does not mention iliopsoas bursa injection as an indication of US guidance.

Infiltration between the Popliteal Artery and Capsule of the Knee (IPACK) Block for Pain Control Following Anterior Cruciate Ligament (ACL) Repair

Thobhani et al (2017) stated that novel regional techniques, including the adductor canal block (ACB) and the local anesthetic infiltration between the popliteal artery and capsule of the knee (IPACK) block, provide an alternative approach for controlling pain following total knee arthroplasty (TKA). This study compared 3 regional techniques (femoral nerve catheter [FNC] block alone, FNC block with IPACK, and ACB with IPACK) on pain scores, opioid consumption, performance during physical therapy, and hospital length of stay (LOS) in patients undergoing TKA. All patients had a continuous peri-neural infusion, either FNC block or ACB. Patients in the IPACK block groups also received a single injection 30-ml IPACK block of 0.25 % ropivacaine. Pain scores and opioid consumption were recorded at post-anesthesia care unit (PACU) discharge and again at 8-hour intervals for 48 hours. Physical therapy performance was measured on post-operative days (POD) 1 and 2, and hospital LOS was recorded. These researchers found no significant differences in the 3 groups with regard to baseline patient demographics. Although these investigators observed no differences in pain scores between the 3 groups, opioid consumption was significantly reduced in the FNC with IPACK group. Physical therapy performance was significantly better on POD 1 in the ACB with IPACK group compared to the other 2 groups. Hospital LOS was significantly shorter in the ACB with IPACK group. The authors concluded that the findings of this study demonstrated that an IPACK block reduced opioid consumption by providing effective supplemental analgesia following TKA compared to the FNC-only technique; ACB with IPACK provided equivalent analgesia and improved physical therapy performance, allowing earlier hospital discharge.

The authors stated that this study had several drawbacks. Because these investigators identified no patients who would fit the criteria to receive ACB only during the study period, this study lacked a group that received ACB only, which would allow better analysis of the contribution of the IPACK block to an ACB. Because the ACB has gained attention by providing adequate analgesia to the anterior knee while minimizing motor impairment, addition of the IPACK block could improve posterior knee analgesia without sacrificing distal motor and sensory impairment. Comparing ACB only to ACB with IPACK block should be a goal for future research. Nevertheless, no prior publications had described the effects of the IPACK block for addressing posterior knee pain following TKA, and thus the opioid-sparing effect of the IPACK block when combined with the FNC block is a novel finding. Retrospective studies may suffer from assignment bias, possibly resulting in baseline differences between groups. However, the consecutive enrollment of patients in this study may have limited selection bias. In addition, this trial was a descriptive study of the benefits of a novel approach to regional analgesia for a common surgical procedure. An investigator needs to know a clinical delta, the difference in expectation that one regional technique provides compared to another technique, to calculate sample size. Because of the novel approach of this study, such information was not available, so this study could suffer from assignment bias. However, a strength of this study was that it allowed other investigator groups to validate these findings, and when needed, to use these findings to calculate a clinical delta for the appropriate sample size needed for a prospective RCT.

Sankineani et al (2018) noted that ACB is a peripheral nerve blockade technique that provides good pain control in patients undergoing TKA, which however does not relieve posterior knee pain. The recent technique of an US-guided IPACK has shown promising results in providing significant posterior knee analgesia without affecting the motor nerves. These researchers carried out a prospective study in 120 patients undergoing unilateral TKA. The initial 60 consecutive patients received ACB + IPACK (Group 1, n = 60), and the subsequent 60 patients received ACB alone (Group 2, n = 60). All patients were evaluated with visual analog scale (VAS) score for pain recorded at 8 hours, POD 1 and POD 2 after the surgery. The secondary outcome measures were range of movement (ROM) and ambulation distance. VAS score showed significantly (p < 0.005) better values in ACB + IPACK group compared to the ACB group. The mean ROM of knee and ambulation distance also showed significantly better values in ACB + IPACK group compared to the ACB group. The authors concluded that ACB + IPACK is a promising technique that offered improved pain management in the immediate post-operative period without affecting the motor function around the knee joint resulting in better ROM and ambulation compared to ACB alone. This was a relatively small study (n = 60 in the ACB + IPACK group); and its findings were confounded by the combined use of ACB and IPACK.

Kim et al (2019) stated that peri-articular injections (PAIs) are becoming a staple component of multi-modal joint pathways. Motor-sparing peripheral nerve blocks, such as the IPACK block and the ACB, may augment PAI in multi-modal analgesic pathways for TKA, but supporting literature remains rare. These researchers hypothesized that the addition of ACB and IPACK block to PAI would lower pain on ambulation on POD 1 compared to PAI alone. This triple-blinded, RCT included 86 patients undergoing unilateral TKA. Patients either received a PAI (control group, n = 43), or an IPACK block with an ACB and modified PAI (intervention group, n = 43). The primary outcome was pain on ambulation on POD 1; secondary outcomes included NRS pain scores, patient satisfaction, and opioid consumption. The intervention group reported significantly lower NRS pain scores on ambulation than the control group on POD 1 (difference in means [95 % CI]: -3.3 [-4.0 to -2.7]; p < 0.001). In addition, NRS pain scores on ambulation on POD 0 (-3.5 [-4.3 to -2.7]; p < 0.001) and POD 2 (-1.0 [-1.9 to -0.1]; p = 0.033) were significantly lower. Patients in the intervention group were more satisfied, had less opioid consumption (p = 0.005, PACU, p = 0.028, POD 0), less intravenous opioids (p < 0.001), and reduced need for intravenous PCA (p = 0.037). The authors concluded that the addition of IPACK block and ACB to PAI significantly improved analgesia and reduced opioid consumption after TKA compared to PAI alone. They stated that this study strongly supported IPACK block and ACB use within a multi-modal analgesic pathway. This was a relatively small study (n = 43 in the ACB + IPACK block + PAI group); and its findings were confounded by the combined use of ACB, IPACK and PAT.

Injection for Low Back Pain

In a systematic review, Hofmeister and colleagues (2019) evaluated the literature comparing US-guided injections to fluoroscopy-guided injections for the management of low back pain (LBP). Medline, Cochrane CENTRAL Register of Controlled Trials, Embase, and NHSEED were searched from 2007 to September 26, 2017. Inclusion criteria included: RCT design, compared US-guided and fluoroscopy-guided injections for LBP; dose and volume of medications injected were identical between trial arms, and reported original data. A total of 101 unique records were identified, and 21 studies were considered for full-text inclusion; 9 studies formed the final data set. Studies comparing US- and fluoroscopy-guided injections for LBP management reported no difference in pain relief, procedure time, number of needle passes, changes in disability indices, complications or AEs, post-procedure opioid consumption, or patient satisfaction. The authors concluded that fluoroscopic guidance of injections for the management of LBP was similar in efficacy to US guidance. These researchers stated that further study is needed to understand the exact role of US in image-guided injections.

Injection for Plantar Fasciitis

Li and co-workers (2014) noted that it is controversial whether US-guided injection of corticosteroid is superior to palpation-guided injection for plantar fasciitis (PF). In a meta-analysis, these investigators compared the effectiveness of US-guided and palpation-guided injection of corticosteroid for the treatment of PF. Databases (Medline, Cochrane library and Embase) and reference lists were searched from their establishment to August 30, 2013 for RCTs comparing US-guided with palpation-guided injection for PF. The Cochrane risk of bias (ROB) tool was used to assess the methodological quality. Outcome measurements were VAS, tenderness threshold (TT), heel tenderness index (HTI), response rate, plantar fascia thickness (PFT), hypo-echogenicity and heel pad thickness (HPT). The statistical analysis was performed with software RevMan 5.2 and Stata 12.0. When I2 was less than 50 %, the fixed-effects model was adopted. Otherwise the randomized-effects model was adopted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the quality of evidence. A total of 5 RCTs with 149 patients were identified and analyzed. Compared with palpation-guided injection, US-guided injection was superior with regard to VAS, TT, response rate, PFT and hypo-echogenicity. However, there was no statistical significance between the 2 groups for HPT and HTI. The authors concluded that US-guided injection of corticosteroid appeared to be more effective than palpation-guided injection; however, these findings need to be confirmed by further research with well-designed and large studies.

David and associates (2017) stated that plantar heel pain, commonly resulting from plantar fasciitis, often results in significant morbidity. Therapeutic options include non-steroidal anti-inflammatory drugs (NSAIDs), orthoses, physical therapy, physical agents (e.g., extracorporeal shock wave therapy (ESWT), laser) and invasive procedures including steroid injections. In a Cochrane review, these researchers examined the effects (benefits and harms) of injected corticosteroids for treating plantar heel pain in adults. They searched the Cochrane Bone, Joint and Muscle Trauma Group Specialized Register, the Cochrane Central Register of Controlled Trials (the Cochrane Library), Medline, Embase, CINAHL, clinical trials registries and conference proceedings; latest search was March 27, 2017; RCTs and quasi-RCTs of corticosteroid injections in the treatment of plantar heel pain in adults were eligible for inclusion. At least 2 review authors independently selected studies, assessed risk of bias and extracted data. These investigators calculated RRs for dichotomous outcomes and mean differences (MDs) for continuous outcome measures. They used a fixed-effect model unless heterogeneity was significant, when a random-effects model was considered. They assessed the overall quality of evidence for individual outcomes using the GRADE approach. These researchers included a total of 39 studies (36 RCTs and 3 quasi-RCTs) that involved a total of 2,492 adults. Most studies were small (median = 59 subjects). Subjects' mean ages ranged from 34 years to 59 years. When reported, most subjects had heel pain for several months. The trials were usually conducted in out-patient specialty clinics of tertiary care hospitals in 17 countries. Steroid injection was given with a local anesthetic agent in 34 trials. Follow-up was from 1 month to over 2 years. With one exception, trials were assessed at high risk of bias in 1or more domains, mostly relating to lack of blinding, including lack of confirmation of allocation concealment. With 2 exceptions, these researchers rated the available evidence as very low quality, implying in each case that they were "very uncertain about the estimate". The 39 trials covered 18 comparisons, with 6 of the 7 trials with 3 or 4 groups providing evidence towards 2 comparisons; 8 trials (724 subjects) compared steroid injection versus placebo or no treatment. Steroid injection may lead to lower heel pain VAS (0 to 100; higher scores = worse pain) in the short-term (less than 1 month) (MD -6.38, 9 5% CI: -11.13 to -1.64; 350 subjects; 5 studies; I² = 65 %; low quality evidence). Based on a minimal clinically significant difference (MCID) of 8 for average heel pain, the 95 % CI included a marginal clinical benefit. This potential benefit was diminished when data were restricted to 3 placebo-controlled trials. Steroid injection made no difference to average heel pain in the medium-term (1 to 6 months follow-up) (MD -3.47, 95 % CI: -8.43 to 1.48; 382 subjects; 6 studies; I² = 40 %; low quality evidence). There was very low quality evidence for no effect on function in the medium-term and for an absence of serious AES (219 subjects, 4 studies). No studies reported on other AEs, such as post-injection pain, and on return to previous activity. There was very low quality evidence for fewer treatment failures (defined variously as persistent heel pain at 8 weeks, steroid injection at 12 weeks, and unrelieved pain at 6 months) after steroid injection. The available evidence for other comparisons was rated as very low quality. These researchers were therefore very uncertain of the estimates for the relative effects on people with heel pain of steroids compared with other interventions in: Tibial nerve block with anesthetics (2 trials); orthoses (4 trials); oral NSAIDs (2 trials); and intensive physiotherapy (1 trial). Physical modalities: ESWT (5 trials); laser (2 trials); and radiation therapy (1 trial). Other invasive procedures: locally injectable NSAID (1 trial); platelet-rich plasma injections (PRP; 5 trials); autologous blood injections (2 trials); botulinum toxin injections (2 trials); cryo-preserved human amniotic membrane injection (1 trial); localized peppering with a needle (1 trial); dry needling (1 trial); and mini-scalpel needle release (1 trial). These investigators were also uncertain about the estimates from trials testing different techniques of local steroid injection: US-guided versus palpation-guided (5 trials); and scintigraphy-guided versus palpation-guided (1 trial). An exploratory analysis involving pooling data from 21 trials reporting on AEs revealed 2 ruptures of plantar fascia (reported in 1 trial) and 3 injection site infections (reported in 2 trials) in 699 participants allocated to steroid injection study arms; 5 trials reported a total of 27 subjects with less serious short-term AEs in the 699 subjects allocated steroid injection study arms. Reported treatments were analgesia, ice or both. Given the high risk of selective reporting for these outcomes and imprecision, this evidence was rated at very low quality. The authors found low quality evidence that local steroid injections compared with placebo or no treatment may slightly reduce heel pain up to 1month but not subsequently. The available evidence for other outcomes of this comparison was very low quality. Where available, the evidence from comparisons of steroid injections with other interventions used to treat heel pain and of different methods of guiding the injection was also very low quality. Although serious AES relating to steroid injection were rare, these were under-reported and a higher risk cannot be ruled out. The authors concluded that further research should focus on establishing the effects (benefits and harms) of injected steroids compared with placebo in typical clinical settings, subsequent to a course of unsuccessful conservative therapy. Ideally, this should be preceded by research, including patient involvement, aimed to obtain consensus on the priority questions for treating plantar heel pain.

Li and colleagues (2018) noted that the argument on whether ESWT and US-guided corticosteroid injections (CSIs) exert an equivalent pain control or which is the better treatment for PF in adults remains to be resolved. These researchers performed a meta-analysis to make a relatively more credible and overall assessment about which treatment method performs better pain control in treatment of PF in adults. From the inception to July 2018, the Embase, PubMed, Web of Science, and Cochrane Library electronic databases were searched for all relevant studies. Only RCTs focusing on comparing ESWT and CSI therapies in PF cases in adults were included. The primary outcome measure was VAS reduction, whereas the secondary outcomes included treatment success rate, recurrence rate, function scores, and AEs. A total of 9 RCTs involving 658 cases were included in this meta-analysis. The findings of this meta-analysis showed that high-intensity ESWT had superior pain relief and success rates relative to the CSI group within 3 months, but the ESWT with low intensity was slightly inferior to CSI for efficacy within 3 months. In addition, patients with CSI may tend to increase the need for the analgesic and more AES may be associated with the ESWT. However, the ESWT and CSI presented similar recurrent rate and functional outcomes. The authors concluded that this analysis showed that the pain relief and success rates were related to energy intensity levels, with the high-intensity ESWT had the highest probability of being the best treatment within 3 months, followed by US-guided CSI, and low-intensity ESWT. These researchers stated that more high-quality RCTs with long-term follow-up duration are needed to further compare the differences of US-guided CSI and ESWT for adults with PF.

Furthermore, an UpToDate review on "Plantar fasciitis" (Buchbinder, 2019) states that "There is moderate-quality evidence that use of ultrasound to guide placement of the injection does not improve pain more than palpation-guided injections".

Injection for Shoulder Pain

Rutten and colleagues (2007) stated that blind injection of the subacromial-subdeltoid bursa (SSB) for diagnostic purposes (Neer test) or therapeutic purposes (corticosteroid therapy) is frequently used. Poor response to previous blind injection or side effects may be due to a misplaced injection. It is assumed that US-guided injections are more accurate than blind injections. In a randomized study, these investigators compared the accuracy of blind injection to that of US-guided injection into the SSB. A total of 20 consecutive patients with impingement syndrome of the shoulder were randomized for blind or US-guided injection in the SSB. Injection was performed either by an experienced orthopedic surgeon or by an experienced musculoskeletal radiologist. A mixture of 1-ml methylprednisolone acetate, 4-ml prilocaine hydrochloride and 0.02-ml (0.01 mmol) gadolinium DTPA was injected. Immediately after injection, a 3D-gradient T1-weighted magnetic resonance imaging (MRI) of the shoulder was performed. The location of the injected fluid was independently assessed by 2 radiologists who were blinded as to the injection technique used. The accuracy of blind and US-guided injection was the same. The fluid was injected into the bursa in all cases. The authors concluded that blind injection into the SSB was as reliable as US-guided injection and could therefore be used in daily routine. These researchers noted that US-guided injections may offer a useful alternative in difficult cases, such as with changed anatomy post-operatively or when there is no effective clinical outcome.

In a prospective, randomized, double-blind study, Dogu and co-workers (2012) compared the accuracy of blind versus US-guided corticosteroid injections in subacromial impingement syndrome and examined the correlation between accuracy of the injection location and clinical outcome. A total of 46 patients with subacromial impingement syndrome were randomized for US-guided (group 1, n = 23) and blind corticosteroid injections (group 2, n = 23); MRI analysis was performed immediately after the injection. Changes in shoulder ROM, pain, and shoulder function were recorded. All patients were assessed before the injection and 6 weeks following the injection. Accurate injections were performed in 15 (65 %) group 1 patients and in 16 (70 %) group 2 patients. There was no statistically significant difference in the injection location accuracy between the 2 groups (p > 0.05). At the end of the sixth week, regardless of whether the injected mixture was found in the subacromial region or not, all of the patients showed improvements in all of the parameters evaluated (p < 0.05). The authors concluded that blind injections performed in the subacromial region by experienced individuals were reliably accurate and could therefore be given in daily routines. Corticosteroid injections in the subacromial region were very effective in improving the pain and functional status of patients with subacromial impingement syndrome during the short-term follow-up.

In a systematic review and meta-analysis, Wu and colleagues (2015) examined the effectiveness of US-guided (USG) versus blind (landmark-guided, LMG) corticosteroid SSB injection in adults with shoulder pain. Searches were performed on PubMed, Ovid Medline, Ovid Embase, Ovid Cochrane CENTRAL, Web of Science, Google Scholar, and Scopus from database inception through March 27, 2015. Studies included trials comparing USG versus LSG injections for the treatment of adults with SSB. Two reviewers independently performed data extraction and appraisal of the studies. The outcome measures collected were decreased VAS and Strengths and Difficulties Questionnaire (SDQ) scores, increased shoulder function scores and shoulder abduction ROM, and the effective rate at 6 weeks after injection. A total of 7 papers including 445 patients were reviewed; 224 received LMG injections and 221 received USG injections. There was a statistically significant difference in favor of USG for pain score [mean difference [MD] = 1.19, 95 % CI: 0.39 to 1.98, p = 0.003] and SDQ score [MD = 5.01, 95 % CI: 1.82, 8.19, p = 0.02] at 6 weeks after injection. Furthermore, there was a statistically significant difference between the groups, with greater improvement reported of shoulder function scores [SMD = 0.89, 95 % CI: 0.56 to 1.23, p < 0.001] and shoulder abduction ROM [MD 32.69, 95 % CI: 14.82 to 50.56, p < 0.001] in the USG group. More effective rate was also reported with USG group and the difference was statistically significant [risk ratio (RR) = 1.6, 95 % CI: 1.02 to 2.50, p = 0.04]. The authors concluded that US-guided corticosteroid injections potentially offered a significantly greater clinical improvement over blind SSB injections in adults with shoulder pain.

In a RCT, Cole and associates (2016) examined the clinical outcome of US-guided subacromial injections compared with blind subacromial injections for subacromial impingement syndrome. A total of 56 shoulders with subacromial impingement syndrome were randomized into 2 groups: 28 shoulders received a subacromial corticosteroid injection with US guidance (US group), and 28 shoulders received a subacromial corticosteroid injection without US guidance (blind group). The VAS for pain with overhead activities and the American Shoulder and Elbow Surgeons (ASES) score were obtained before the injection and at 6 weeks after the injection. The VAS score for pain with overhead activities decreased from 59 ± 5 mm (mean ± SEM) before the injection to 33 ± 6 mm at 6 weeks after the injection in the US group (p < 0.001) and from 63 ± 4 mm to 39 ± 6 mm, respectively, in the blind group (p < 0.001). The decrease in the VAS score was not significantly different between the groups (p > 0.999). The ASES score increased from 57 ± 2 before the injection to 68 ± 3 at 6 weeks after the injection in the US group (p < 0.01) and from 54 ± 3 before the injection to 65 ± 4 after the injection in the blind group (p < 0.01), with no significant difference between the groups (p = 0.7); 4 shoulders (14 %) in the US group and 6 shoulders (21 %) in the blind group eventually needed surgery (p = 0.7). The authors concluded that no significant differences were found in the clinical outcome when comparing US-guided subacromial injections to blind subacromial injections for subacromial impingement syndrome.

Intercostal Nerve Block

Shankar and Eastwood (2010) noted that steroid injection around the intercostal nerves (ICN) is one of the therapeutic options for intercostal neuralgia. The technique may be performed blindly, under fluoroscopic guidance (FSG) or with the use of USG. This study was a retrospective comparison of image guidance for intercostal steroid injections. After Institutional Review Board (IRB) approval, a retrospective review of all patient charts who received intercostal steroid injections from 2005 to 2009 was performed. A total of 39 blocks were performed in that period; 12 were USG blocks and 27 FSG blocks. The pre-procedure VAS and post-procedure VAS and the duration of pain relief were compared between the 2 techniques. The median change in the VAS for FSG and USG were -5.000 and -4.000, respectively, and duration of pain relief with a MD of 2 weeks (95 % CI: -4 to 7). There were 2 occasions of intravascular spread noticed with the FSG although this should not affect the study result as the needle was re-positioned and steroid injected only after contrast dye confirmation. The authors concluded that with similar change in VAS scores and duration of pain relief between the 2 guidance methods based on this retrospective study, both image guidance techniques may offer similar pain relief. The main drawbacks of this study were its retrospective design, small sample size (n = 12 for US guidance group), and the lack of a comparison group of "blind" injections by means of anatomic landmarks.

Bhatia et al (2013) stated that ICN injections are routinely performed under anatomic landmark or FSG for acute and chronic pain indications; US is being used increasingly to perform ICN injections, but there is lack of evidence to support the benefits of US over conventional techniques. These researchers compared guidance with US versus anatomic landmarks for accuracy and safety of ICN injections in cadavers in a 2-phase study that included evaluation of deposition of injected dye by dissection and spread of contrast on fluoroscopy. A cadaver experiment was performed to validate US as an imaging modality for ICN blocks. In the first phase of the study, 12 ICN injections with 2 different volumes of dye were performed in 1 cadaver using anatomic landmarks on one side and US-guidance on the other (6 injections on each side). The cadaver was then dissected to evaluate spread of the dye. The second phase of the study consisted of 74 ICN injections (37 US-guided and 37 using anatomic landmarks) of contrast dye in 6 non-embalmed cadavers followed by fluoroscopy to evaluate spread of the contrast dye. In the first phase of the study, the intercostal space was identified with US at all levels. Injection of 2-ml of dye was sufficient to ensure complete staining of the ICN for 5 of 6 US-guided injections; but anatomic landmark guidance resulted in correct injection at only 2 of 6 intercostal spaces. No intravascular injection was found on dissection with either of the guidance techniques. In the second phase of the study, US-guidance was associated with a higher rate of intercostal spread of 1 ml of contrast dye on fluoroscopy compared with anatomic landmarks guidance (97 % versus 70 %; p = 0.017). The authors concluded that US conferred higher accuracy and allowed use of lower volumes of injectate compared with anatomic landmarks as a guidance method for ICN injections in cadavers. They stated that US may be a viable alternative to anatomic landmarks as a guidance method for ICN injections. This was a cadaveric study.

Thallaj et al (2015) tested the hypothesis that identification and blockade of the inter-costo-brachial nerve (ICBN) can be achieved under US guidance using a small volume of local anesthetic. A total of 28 adult male volunteers were examined; ICBN blockade was performed using 1-ml of 2 % lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. The ICBN appeared as a hyper-echoic structure. The nerve diameter was 2.3 ± 0.28 mm, and the depth was 9 ± 0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3 ± 1.6 cm anteriorly; 6.2 ± 2.9 cm posteriorly; 9.4 ± 2.9 cm proximally; and 9.2 ± 4.4 cm distally; ICBN blockade using 1-ml of local anesthetic was successful in all cases. The authors concluded that the present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade. These investigators stated that the volunteers in this study were all men and had a normal or low BMI; therefore, the observation might not be accurate for patients with a higher BMI or who are female. They recommended further studies to support and apply these findings to improve patient care.

In a pilot study, Wijayasinghe et al (2016) examined the feasibility of ICBN blockade and evaluated its effects on pain and sensory function in patients with persistent pain after breast cancer surgery (PPBCS). This prospective pilot study was performed in 2 parts: Part 1 determined the sono-anatomy of the ICBN; and part 2 examined effects of the US-guided ICBN blockade in patients with PPBCS. Part 1: 16 un-operated, pain-free BC patients underwent systematic US to establish the sono-anatomy of the ICBN. Part 2: 6 patients with PPBCS who had pain in the axilla and upper arm were recruited for the study. Summed pain intensity (SPI) scores and sensory function were measured before and 30 mins after the block was administered; SPI is a combined pain score of NRS at rest, movement, and 100 kPa pressure applied to the maximum point of pain using pressure algometry (max = 30). Sensory function was measured using quantitative sensory testing, which consisted of sensory mapping, thermal thresholds, supra-threshold heat pain perception as well as heat and pressure pain thresholds. The ICBN block was performed under US guidance and 10-ml 0.5 % bupivacaine was injected. Outcome measures were the ability to perform the ICBN block and its analgesic and sensory effects. Only the second intercostal space could be seen on US, which was adequate to perform the ICBN block. The mean difference in SPI was -9 NRS points (95 % CI: -14.1 to -3.9, p = 0.006). All patients had pre-existing areas of hypoesthesia that decreased in size in 4/6 patients after the block. The authors concluded that they had successfully managed to block the ICBN using US guidance and demonstrated an analgesic effect in patients in PPBCS. The authors stated that the main drawback of this pilot study was its small sample size (n= 6), but despite this, a statistically significant effect was observed. They suggested that a RCT is needed to ascertain the role of ICBN blockade in PPBCS.

Intra-Articular Steroid Injection for the Knee

An UpToDate review on "Intraarticular and soft tissue injections: What agent(s) to inject and how frequently?" (Roberts, 2019) does not mention the utility of imaging guidance (i.e., arthrogram/fluoroscopic/ultrasound).

Lavage of the Shoulder Joint

Del Cura et al (2010) noted that ultrasonography (US) is the most appropriate tool for interventional procedures in the musculoskeletal system when the lesion is visible on US. Procedures performed under US guidance include: taking biopsies; draining abscesses; bursitis; hematomas or muscle tears; treating cystic lesions; diagnostic or therapeutic arthrocentesis; injecting substances into joints or lesions; aspirating calcium deposits and extracting foreign bodies. Although some of these procedures are often carried out without imaging guidance, US guidance improves their efficacy. Drainage can be performed with catheters or needles and makes it possible to avoid more aggressive treatments in most cases. Urokinase is useful for draining hematomas or fibrinous collections. Injecting corticoids is useful in the treatment of synovial cysts, Baker's cyst, tendinitis, and non-infective arthritis. Calcifying tendinitis of the shoulder can be treated effectively with percutaneous calcium lavage.

Sammour et al (2016) stated that musculo-skeletal US has evolved throughout the past 10 years. This procedure allows accurate corticosteroid injections guidance. Precision is much higher than the infiltration performed blindly or under fluoroscopy. These researchers described their technique in US-guided infiltration of the shoulder with an overview of the results. A total of 123 cases of US-guided infiltration of the shoulder were selected in the authors’ institution from July 2011 to June 2012. They were divided into sub-acromial sub-deltoid bursitis, biceps tenosynovitis, acromioclavicular osteoarthritis (OA), adhesive capsulitis and calcific tendinosis lavage and aspiration. The infiltration technique and the sonographic appearance in each condition were described. The rate of improvement was estimated between 70 % and 80 %. The authors concluded that US-guided infiltration provided an accurate and minimally invasive therapeutic option before any surgery. Recovery and socio-professional integration prove to be optimal and fast.

Furthermore, an UpToDate review on "Musculoskeletal ultrasound of the shoulder" (Finnoff, 2020) states that "Calcific tendinopathy appears as hyperechoic foci within the tendon. During the calcific phase, the calcification has significant posterior acoustic shadowing. The posterior acoustic shadowing becomes less prominent as the calcification progresses into the resorptive phase. Occasionally, hyperemia can be seen within the calcification or surrounding tendon tissue during the resorptive phase. During the resorptive phase, the calcification may be amenable to treatment via US-guided lavage and aspiration of the calcific material".

Lumbar Plexus Block with Hydrodissection

Lam et al (2017) stated that deep nerve hydrodissection uses fluid injection under pressure to separate nerves from areas of suspected fascial compression, which are increasingly viewed as potential perpetuating factors in recalcitrant neuropathic pain/complex regional pain. The usage of 5 % dextrose water (D5W) as a primary injectate for hydrodissection, with or without low-dose anesthetic, could limit anesthetic-related toxicity. An analgesic effect of D5W upon perineural injection in patients with chronic neuropathic pain has recently been described. These researchers described US-guided methods for hydrodissection of deep nerve structures in the upper torso, including the stellate ganglion, brachial plexus, cervical nerve roots, and paravertebral spaces. They retrospectively reviewed the outcomes of 100 hydrodissection treatments in 26 consecutive cases with a neuropathic pain duration of 16 ± 12.2 months and the mean Numeric Pain Rating Scale (NPRS; 0 to 10 pain level) of 8.3 ± 1.3. The mean percentage of analgesia during each treatment session involving D5W injection without anesthetic was 88.1 % ± 9.8 %. The pre-treatment NPRS score of 8.3 ± 1.3 improved to 1.9 ± 0.9 at 2 months after the last treatment. Patients received 3.8 ± 2.6 treatments over 9.7 ± 7.8 months from the first treatment to the 2-month post-treatment follow-up. Pain improvement exceeded 50 % in all cases and 75 % in half. The authors concluded that these findings confirmed the analgesic effect of D5W injection and suggested that hydrodissection using D5W provided cumulative pain reduction. These preliminary findings need to be validated by well-designed studies.

Median Nerve Block

Lewis et al (2015) noted that peripheral nerve blocks can be performed using US guidance. It is unclear if this method of nerve location has benefits over other existing methods. This review was originally published in 2009 and was updated in 2014. The objective of this Cochrane review was to examine if the use of US to guide peripheral nerve blockade has any advantages over other methods of peripheral nerve location. Specifically, these researchers examined if the use of US guidance improved success rates and effectiveness of regional anesthetic blocks, by increasing the number of blocks that were assessed as adequate, and reduced the complications, such as cardio-respiratory arrest, pneumothorax or vascular puncture, associated with the performance of regional anesthetic blocks. The authors concluded that there was evidence that peripheral nerve blocks performed by US guidance alone, or in combination with PNS, were superior in terms of improved sensory and motor block, reduced need for supplementation and fewer minor complications reported. Using US alone shortened performance time when compared with nerve stimulation, but when used in combination with PNS it increased performance time. The authors were unable to determine whether these findings reflect the use of US in experienced hands and it was beyond the scope of this review to consider the learning curve associated with peripheral nerve blocks by US technique compared with other methods.

In a Cochrane review, Walker et al (2019) examined if the use of US to guide peripheral nerve blockade has any advantages over other methods of peripheral nerve location. The authors concluded that in experienced hands, US provided at least as good success rates as other methods of peripheral nerve location. Individual studies have demonstrated that US may reduce complication rates and improve quality, performance time, and time to onset of blocks. Due to wide variations in study outcomes these researchers chose not to combine the studies in their analysis.

In a Cochrane review, Guay et al (2019) examined if US guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of decreasing failure rate or the rate of complications. The authors concluded that US guidance for regional blockade in children probably decreased the risk of failed block. It increased the duration of the block and probably decreased pain scores at 1 hour after surgery; there may be little or no difference in the risks of some minor complications. These investigators stated that the 5 ongoing studies may alter the conclusions of the review once published and assessed.

Occipital Nerve Block

In a prospective, randomized, placebo-controlled, double-blind pilot trial, Palamar et al (2015) compared the effectiveness of US-guided greater occipital nerve block (GONB) using bupivacaine 0.5 % and placebo on clinical improvement in 23 patients with refractory migraine without aura (MWOA). Patients were randomly assigned to receive either GONB with local anesthetic (bupivacaine 0.5 % 1.5 ml) or GON injection with normal saline (0.9 % 1.5 ml). Ultrasound-guided GONB was carried out to more accurately locate the nerve. All procedures were performed using a 7- to 13-MHz high-resolution linear US transducer. The treatment group was comprised of 11 patients and the placebo group was comprised of 12 patients. The primary outcome measure was the change in the headache severity score during the 1-month post-intervention period. Headache severity was assessed with a VAS from 0 (no pain) to 10 (intense pain). In both groups, a decrease in headache intensity on the injection side was observed during the first post-injection week and continued until the second week. After the second week, the improvement continued in the treatment group, and the VAS score reached 0.97 at the end of the fourth week. In the placebo group after the second week, the VAS values increased again and nearly reached the pre-injection levels. The decrease in the monthly average pain intensity score on the injected side was statistically significant in the treatment group (p = 0.003), but not in the placebo group (p = 0.110). No statistically significant difference in the monthly average pain intensity score was observed on the un-injected side in either group (treatment group, p = 0.994; placebo group, p = 0.987). No serious side effect was observed after the treatment in either group. The authors concluded that US-guided GONB with bupivacaine for the treatment of migraine patients was a safe, simple, and effective technique without severe adverse effects. To increase the effectiveness of the injection, and to implement the isolated GONB, ultrasonography guidance could be suggested. The drawbacks of this pilot study include small sample size (n = 11 in the US-guided group) and short follow-up duration (1 month).

In a prospective open-label stud, Pingree et al (2017) examined the analgesic effects of an US-guided GONB at the level of C2, as the nerve courses superficially to the obliquus capitis inferior muscle. A total of 14 injections with US-guided GONBs at the level of C2 were performed on patients with a diagnosis of occipital neuralgia or cervicogenic headache; NRS pain scores were recorded pre-injection and at 30 mins, 2 weeks, and 4 weeks after injection. Anesthesia in the GON distribution was achieved for 86 % of patients at 30 mins post-injection. Compared with baseline, NRS scores decreased by a mean of 3.78 at 30 mins (p < 0.001), 2.64 at 2 weeks (p = 0.006), and 2.21 at 4 weeks (p = 0.01). There were no significant AEs reported during the study period. The authors concluded that their study demonstrated successful blockade of the GON at the level of C2 using a novel US-guided technique, and that significant reductions in pain scores were observed over the 4-week study period without AEs. The observations from this study provided preliminary data for future randomized trials involving patients with occipital neuralgia and cervicogenic headache.

Platelet-Rich Plasma Injections in the Treatment of Hip Osteoarthritis

Ali and colleagues (2018) examined if US-guided platelet-rich plasma (PRP) injection has any role in improving clinical outcomes in patients with hip osteoarthritis (OA). These investigators carried out a search of the National Institute for Health and Care Excellence database using the Healthcare Databases Advanced Search tool. The PubMed database was also utilized to search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index of Nursing and Allied Health and Allied and Complimentary Medicine databases. The Preferred Reporting Items for Systematic Review and Meta-Analysis methodology guidance was employed and a quality assessment was performed using the Jadad score. A total of 3 randomized clinical trials met the inclusion criteria and were included for analysis. All 3 studies were of good quality based on the Jadad score. A total of 115 patients out of 254 received PRP injections under US guidance. The PRP recipient group included 61 men and 54 women aged 53 to 71 years. Outcome scores showed an improvement of symptoms and function maintained up to 12 months following PRP injection. The authors concluded that available evidence indicated that intra-articular PRP injections of the hip, performed under US guidance to treat hip OA, were well-tolerated and potentially effective in delivering long-term and clinically significant pain reduction and functional improvement in patients with hip OA. Moreover, these researchers stated that larger future trials including a placebo group are needed to further evaluate these promising findings.

Subtalar Joint Injection

Reach et al (2009) stated that US is an emerging imaging modality that affords dynamic, real-time, cost-effective and surgeon controlled visualization of the foot and ankle. These researchers evaluated the accuracy of US-guided injections for common injection sites in the foot and ankle. In 10 fresh cadaver feet, US guidance was utilized to inject a methylene blue-saline mixture into the first metatarsophalangeal (MTP) joint, the second MTP joint, the tibio-talar joint, the Achilles peritendinous space, the flexor hallucis longus sheath, the posterior tibial tendon sheath, and the subtalar joint. Dissection was then undertaken to assess injection accuracy; US guidance allowed the avoidance of intervening neurovascular and tendinous structures; US-guided MTP, ankle, Achilles, PTT and FHL peritendinous injections were 100 % accurate; US-guided subtalar injection was 90 % accurate. The authors concluded that US appeared to be a highly accurate method of localizing injections into a variety of locations in the foot and ankle. These investigators stated that US’s ability to display soft-tissue structures may be an advantage over blind injection and fluoroscopic injection techniques. This was a cadaveric study.

Khosla et al (2009) noted that US has been increasingly utilized in procedures involving intra-articular injections. These researchers compared the accuracy of intra-articular injections of the foot and ankle using palpation versus dynamic US in a cadaver model. A total of 14 lightly embalmed cadaver specimens without notable OA were used. A 0.22-G needle was placed by a foot and ankle orthopedic surgeon into the first and second tarsometatarsal (TMT) joints, subtalar joint, and ankle joint. The needle was initially placed using palpation, evaluated with US by an experienced rheumatologist, and re-inserted if necessary. Needle placement was confirmed with injection of an Omnipaque/methylene blue solution and examined under fluoroscopy, followed by dissection. Palpation and US were 100 % accurate in subtalar and ankle joint injections. Using palpation, the needle was correctly placed into the first TMT joint in 3 of 14 cadavers, and in 4 of 14 cadavers for the second TMT joint. Using US, the needle was correctly placed into the first TMT joint in 10 of 14 cadavers, and into the second TMT joint in 8 of 14 cadavers. When grouped, US was significantly more accurate for intra-articular needle placement compared to palpation in the mid-foot (p = 0.003). On 3 specimens, dye extended beyond the second TMT joint. The authors concluded that intra-articular injections of the subtalar and ankle joints could be successfully performed utilizing palpation alone; US guidance significantly increased injection accuracy into the TMT joints compared to palpation alone and therefore US or fluoroscopy was performed when injecting these TMT joints. When using selective diagnostic injections into a TMT joint to assess for the symptomatic joint and potential need for arthrodesis, the injected anesthetic may not remain isolated within that joint. These isolated TMT injections should not be done to answer that question without fluoroscopy confirmation with radiopaque dye demonstrating the injected fluid remained within the one joint of interest.

Superior Cluneal Nerve Injection

Bodner et al (2016) stated that LBP is a disabling and common condition, whose etiology often remains unknown. A suggested, however rarely considered, cause is neuropathy of the medial branch of the superior cluneal nerves (mSCN) – either at the level of the originating roots or at the point where it crosses the iliac crest, where it is ensheathed by an osseo-ligamentous tunnel. Diagnosis and treatment have, to-date, been restricted to clinical assessment and blind infiltration with local anesthetics. In an interventional cadaver study and case-series study, these investigators examined if visualization and assessment of the mSCN with high-resolution US (HRUS) is feasible. Visualization of the mSCN was assessed in 7 anatomic specimens, and findings were confirmed by HRUS-guided ink marking of the nerve and consecutive dissection. In addition, a patient chart and image review was performed of patients assessed at the authors’ department with the diagnosis of mSCN neuropathy. The mSCN could be visualized in 12 of 14 cases in anatomical specimens, as confirmed by dissection; 9 patients were diagnosed with mSCN syndrome of idiopathic or traumatic origin. Diagnosis was confirmed in all of them, with complete resolution of symptoms after HRUS-guided selective nerve block. The authors concluded that it is possible to visualize the mSCN in the majority of anatomical specimens. The patients described may indicate a higher incidence of mSCN syndrome than has been recognized; and mSCN syndrome should be considered in patients with LBP of unknown origin, and HRUS may be able to facilitate nerve detection and US-guided nerve block. Moreover, these researchers stated that these findings were first results that need to be evaluated in a systematic, prospective and controlled manner.

Tendon Injection

Juel et al (2013) established a method for injecting corticosteroid into the rotator interval under US guidance and measured the effect on function, pain and ROM after 4 and 12 weeks. This study involved a multi-center cohort trial and was carried out at out-patient clinics of the physical medicine and rehabilitation departments in Norway. A total of 39 patients with adhesive capsulitis lasting between 3 and 12 months were included in this trial; US-guided corticosteroid and lidocaine injection into the rotator interval medial to the biceps tendon using 20-mg triamcinolone hexacetat and 3-ml 20 mg/ml xylocaine. Change in the shoulder pain and disability index score (SPADI) after 12 weeks was recorded. The change in SPADI was 42 points (95 % CI: 33 to 51). Changes in the secondary outcomes showed highly statistically significant increase in active and passive ROM. One US-guided corticosteroid injection into the rotator interval appeared to give significant improvement in SPADI and active ROM after 12 weeks. The authors concluded that this study was regarded as regular clinical procedure as injections with triamcinolone already is standard treatment. This was a small study (n = 39) with short-term follow-up (12 weeks).

Wheeler et al (2016) compared outcomes after 2 different high-volume image-guided injection (HVIGI) procedures performed under direct US guidance in patients with chronic non-insertional Achilles tendinopathy. In group A, HVIGI involved high-volume (10-ml of 1 % lidocaine combined with 40-ml of saline) and no dry needling. In group B, HVIGI involved a smaller volume (10-ml of 1 % lidocaine combined with 20-ml of saline) and dry needling of the Achilles tendon. A total of 34 patients were identified from the clinical records, with mean age of 50.6 (range of 26 to 83) years and mean follow-up duration of 277 (range of 49 to 596) days. The change between the pre-injection and post-injection Victorian Institute of Sports Assessment-Achilles scores of 33.4 ± 22.5 points in group A and 6.94 ± 22.2 points in group B, was statistically significant (p = 0.002). In group A, 3 patients (16.7 %) required surgical treatment compared with 6 patients (37.5 %) in group B requiring surgical treatment (p = 0.180). The authors concluded the findings of this study indicated that a higher volume without dry needling compared with a lower volume with dry needling resulted in greater improvement in non-insertional Achilles tendinopathy. However, confounding factors meant it was not possible to state that this difference was solely due to different injection techniques. This was a small study (n = 34); its findings need to be validated by well-designed studies.

Mardani-Kivi et al (2018) compared clinical results of US-guided corticosteroid injection, intra-sheath versus extra-sheath of the finger flexor tendon. A total of 166 patients with trigger finger were evaluated in a triple-blind, randomized clinical trial study. All the patients were injected with 1-ml of 40 mg/ml methyl prednisolone acetate, under US-guidance; 50 % the patients were injected extra-sheath, while the other 50 % were injected intra-sheath at the level of first annular pulley. The 2 groups were comparable in baseline characteristics (age, gender, dominant hand, involved hand and finger, and the symptoms duration). No significant difference was observed in the 2 groups with regards to Quinnell grading. In the final visit, 94 % of patients from each group were symptom-free. The authors concluded that results of corticosteroid injection intra-sheath or extra-sheath of the finger flexor tendon under US guidance in patients with trigger finger were comparably alike; extra-sheath injection at the level of A1 pulley was as effective as an intra-sheath administration. The main drawback of this trial was the lack of a non-US guidance comparison group.

Laurell et al (2011) noted that the ankle region is frequently involved in juvenile idiopathic arthritis (JIA) but difficult to examine clinically due to its anatomical complexity. These investigators examined the role of US of the ankle and mid-foot (ankle region) in JIA. Doppler-US detected synovial hypertrophy, effusion and hyperemia and US was used for guidance of steroid injection and assessment of treatment efficacy. A total of 40 swollen ankles regions were studied in 30 patients (median age of 6.5 years, range of 1 to 16) with JIA. All patients were assessed clinically, by US (synovial hypertrophy, effusion) and by color Doppler (synovial hyperemia) before and 4 weeks after US-guided steroid injection. US detected 121 compartments with active disease (joints, tendon sheaths and 1 ganglion cyst). Multiple compartments were involved in 80 % of the ankle regions. The talo-crural joint, posterior subtalar joint, mid-foot joints and tendon sheaths were affected in 78 %, 65 %, 30 % and 55 %, respectively; 50 active tendon sheaths were detected, and multiple tendons were involved in 12 of the ankles. US guidance allowed accurate placement of the corticosteroid in all 85 injected compartments, with a low rate of subcutaneous atrophy (4.7 %). Normalization or regression of synovial hypertrophy was obtained in 89 %, and normalization of synovial hyperemia in 89 %. Clinical resolution of active arthritis was noted in 72 % of the ankles. The authors concluded that US enabled exact guidance of steroid injections with a low rate of subcutaneous atrophy, and was well-suited for follow-up examinations. Normalization or regression of synovial hypertrophy and hyperemia was achieved in most cases, suggesting that US assessment prior to steroid injection, and US guidance of injections in this region would potentially improve treatment efficacy.

Young et al (2015) stated that the subtalar joint is commonly affected in children with JIA and is challenging to treat percutaneously. These researchers described the technique for treating the subtalar joint with US-guided corticosteroid injections in children and young adults with JIA and evaluated the safety of the treatment. They retrospectively analyzed 122 patients (aged 15 months to 29 years) with JIA who were referred by a pediatric rheumatologist for corticosteroid injection therapy for symptoms related to the hind-foot or ankle. In these patients the diseased subtalar joint was targeted for therapy, often in conjunction with adjacent affected joints or tendon sheaths of the ankle. They used a protocol based on age, weight and joint for triamcinolone hexacetonide or triamcinolone acetonide dose prescription. A total of 241 subtalar joint corticosteroid injections were performed under US guidance, including 68 repeat injections for recurrent symptoms in 26 of the 122 children and young adults. The average time interval between repeat injections was 24.8 months (range of 2.2 to 130.7, median of 14.2). Subcutaneous tissue atrophy and skin hypo-pigmentation were the primary complications, which occurred in 3.9 % of the injections. The authors concluded that with appropriate training and practice, the subtalar joint could be reliably and safely targeted with US-guided corticosteroid injection to treat symptoms related to JIA.

Trigger Finger Injection

Callegari et al (2011) noted that stenosing tenosynovitis (trigger finger) is one of the most common causes of pain and disability in the hand, which may often require treatment with anti-inflammatory drugs, corticosteroid injection, or open surgery. However, there is still room for improvement in the treatment of this condition by corticosteroid injection. The mechanical, viscoelastic, and anti-nociceptive properties of hyaluronic acid (HA) may potentially support the use of this molecule in association with corticosteroids for the treatment of trigger finger. In a single-center, open-label, randomized study, these researchers examined the feasibility and safety of ultrasound (US)-guided injection of a corticosteroid and HA compared, for the first time, with open surgery for the treatment of trigger finger. Consecutive patients aged between 35 and 70 years with US-confirmed diagnosis of trigger finger were included. Patients were randomly assigned to either US-guided injection of methylprednisolone acetate 40 mg/ml with 0.8 ml lidocaine into the flexor sheath plus injection of 1 ml HA 0.8 % 10 days later (n = 15; group A), or to open surgical release of the first annular pulley (n = 15; group B). Clinical assessment of the digital articular chain was conducted prior to treatment and after 6 weeks, and 3, 6, and 12 months. The duration of abstention from work and/or sports activity, and any treatment complications or additional treatment requirements (e.g., physiotherapy, compression, medication) were also recorded. A total of 14 patients (93.3 %) in group A had complete symptom resolution at 6 months, which persisted for 12 months in 11 patients (73.3% ), while 3 patients experienced recurrences and 1 experienced no symptom improvements. No patients in group A reported major or minor complications during or after corticosteroid injection, or required a compression bandage. All 15 patients in group B achieved complete resolution of articular impairment by 3 weeks after surgery, but 10 patients were assigned to physiotherapy and local and/or oral analgesics for complete resolution of symptoms, which was approximately 30 to 40 days post-surgery. The mean duration of abstention from work and/or sport was 2 to 3 days in group A and 26 days in group B. The authors concluded that although the limited sample size did not allow any statistical comparison between treatment groups, and therefore all the findings should be regarded as preliminary, the results of this explorative study suggested that US-guided injection of a corticosteroid and HA could be a safe and feasible approach for the treatment of trigger finger. It was also associated with a shorter recovery time than open surgery, which led to a reduced abstention from sports and, in particular, work activities, and thus may have some pharmaco-economic implications, which may be further examined. In light of the promising findings obtained in this investigation, further studies comparing US-guided injection of corticosteroid plus HA with corticosteroid alone are recommended in order to clarify the actual benefits attributable to HA.

The authors stated that this study had several drawbacks. A lack of a corticosteroid-only treatment arm meant that any benefits of adding HA to the regimen of injection compared with corticosteroid alone cannot be shown. In light of the promising results obtained in this investigation, further study comparing ultrasound-guided injection of corticosteroid plus HA with corticosteroid alone, or exploring other treatment strategies (e.g., no US-guided injection, corticosteroid only versus surgery) is recommended. Furthermore, due to small patient numbers in this study (a total of 30 subjects) , it was not possible to analyze for any trends in the duration of symptoms or number of injections and success rates. These researchers stated that further studies with a larger sample size are needed to provide new insights on the safety and effectiveness of US-guided injection of corticosteroid plus HA. It also must be acknowledged that, due to the explorative nature of this study and the low number of patients enrolled, neither a calculation of power nor a statistical comparison between groups were performed.

In a prospective, double-blinded, randomized controlled trial (RCT), Liu et al (2015) examined the effects of US-guided injections of HA versus steroid for trigger fingers in adults. Subjects with a diagnosis of trigger finger (n = 36; 39 affected digits) received treatment and were evaluated. Subjects were randomly assigned to HA and steroid injection groups. Both study medications were injected separately via US guidance with 1 injection. The classification of trigger grading, pain, functional disability, and patient satisfaction were evaluated before the injection and 3 weeks and 3 months after the injection. At 3 months, 12 patients (66.7 %) in the HA group and 17 patients (89.5 %) in the steroid group exhibited no triggering of the affected fingers (p = 0.124). The treatment results at 3 weeks and 3 months showed similar changes in the Quinnell scale (p = 0.057 and 0.931, respectively). A statistically significant interaction effect between group and time was found for visual analog scale (VAS) and Michigan Hand Outcome Questionnaire (MHQ) evaluation (p < 0.05). The steroid group had a lower VAS at 3 months after injection (steroid 0.5 ± 1.1 versus HA 2.7 ± 2.4; p < 0.001). The HA group demonstrated continuing significant improvement in MHQ at 3 months (change from 3 week: steroid -2.6 ± 14.1 versus HA 19.1 ± 37.0; p = 0.023; d = 0.78). The authors concluded that US-guided injection of HA demonstrated promising results for the treatment of trigger fingers. These researchers stated that the optimal frequency, dosage, and molecular weight of HA injections for trigger fingers deserve further investigation for future clinical applications.

Cecen et al (2015) noted that trigger digit is one of the most common causes of pain and disability in the hand. The mainstay of conservative treatment of this disease has been local steroid injection into the tendon sheath. In a prospective, randomized, case-control study, these investigators examined the clinical benefit of an US-guided corticosteroid injection compared to a blinded application. A total of 74 patients, who suffered from persistent or increasing symptoms of a single trigger digit, were enrolled in this trial. All patients were treated with an injection of 40 mg/1 ml methylprednisolone acetate into the flexor tendon sheath at the level of the A1 pulley; 50 % of the patients had their injections under US control (USG) and 50 % without (blinded injection group, BIG). Associated metabolic diseases were recorded. At the 6-week and 6-month follow-up examinations, the complication rate and the need for a second injection were assessed. The outcome was rated using the Quinnell grading. The pain level was assessed using the VAS. A total of 4 patients were excluded due to lack of follow-up. Both study groups were comparable in respect of age, hand dominance and associated diseases. There were significantly more female patients in the USG group (32 versus 23 %). After the corticosteroid injections, all patients improved significantly in terms of pain level and the Quinnell grading at 6 weeks and 6 months after the intervention in comparison to the pre-injection status. There were no significant differences between the groups; 9 patients (13 %) needed a second injection (6 of BIG, 3 of USG), all of whom had diabetes mellitus. No local complications were observed following the injections. The authors concluded that the use of US-guided injection of corticosteroid may be associated with extra time and effort, with no superior clinical benefits compared to the blinded technique. Level of Evidence = 1 (prospective randomized study).

Wang et al (2017) stated that US is a versatile imaging modality that can be used by upper extremity (UE) surgeons for diagnostic purposes and guided injections. The perceptions of US for diagnosis and treatment among UE surgeons and its barriers for adoption have not been formally surveyed. These researchers determined the current usage of musculoskeletal US for diagnostic purposes and guided injections by UE surgeons and their reasons for using it or not using it in practice. A 22-question survey was distributed to the American Society for Surgery of the Hand (ASSH). The survey questions consisted of respondent characteristic questions and questions pertaining to the use of US. Chi-square analysis was performed to assess for a difference in US usage across respondent characteristics. A total of 304 (43 %) answered that they have an US machine in their office; 51 % (362) of the respondents used US for diagnostic purposes; 55 (8 %) of the survey respondents used US to diagnose carpal tunnel syndrome; 168 (23.5 %) respondents reported that they used US for guided injections. There was a statistically significant difference between access to an US machine in the office by practice setting and use of US for diagnostic purposes by practice setting. The authors concluded that the use of US by UE surgeons is split for diagnostic purposes, with fewer surgeons using US to diagnose carpal tunnel syndrome and guided injections. These investigators stated that US machine availability and the use of US for diagnosis appear to be influenced by practice setting.

Hansen et al (2017) noted that trigger finger is a common condition with a lifetime prevalence of 2 %. Corticosteroid injection is often considered as a first-line intervention with reported cure rates between 60 % and 90 % in observational cohorts. However, open surgery remains the most effective treatment with reported cure rates near 100 %. Head-to-head trials on these treatments are limited. In a single-center RCT, these investigators examined the efficacy of open surgery compared with US-guided corticosteroid injections with a 1-year follow-up. A total of 165 patients received either open surgery (n = 81) or US-guided corticosteroid injection (n = 84). Follow-up was conducted at 3 and 12 months. If the finger had normal movement or normal movement with discomfort at latest follow-up, the outcome was considered a success. Secondary outcomes were post-procedural pain and complications. The groups were similar at baseline except for lower alcohol consumption in the open surgery group. At 3 months, 86 % and 99 % were successfully treated after corticosteroid injection and open surgery, respectively. At 12 months, 49 % and 99 % were considered successfully treated after corticosteroid injection and open surgery, respectively. The pain score at latest follow-up was significantly higher in the corticosteroid injection group. Complications after open surgery were more severe and included 3 superficial infections and 1 iatrogenic nerve lesion. After corticosteroid injection 11 patients experienced a steroid flare and 2 had fat necrosis at the site of injection. The authors concluded that open surgery was superior to US-guided corticosteroid injections; however, complications following open surgery were more severe.

Thread Trigger Finger Release With or Without Hydrodissection

Guo et al (2018) noted that after the thread transecting technique was successfully applied for the thread carpal tunnel release, these investigators researched using the same technique in the thread trigger finger release (TTFR). This study was designed to test the operational feasibility of the TTFR on cadavers and verify the limits of division on the first annular (A1) pulley to ensure a complete trigger finger release with minimal iatrogenic injuries. The procedure of TTFR was performed on 14 fingers and 4 thumbs of 4 un-embalmed cadaveric hands. After the procedures, all fingers and thumbs were dissected and visually assessed. All of the digits and thumbs demonstrated a complete A1 pulley release. There was no injury to the neurovascular bundle (radial digital nerve in case of thumb), flexor tendon, or A2 pulley for each case. The authors concluded that this cadaveric study showed that the technique of TTFR was safe and effective, and future clinical study is needed to verify the findings of this study.

Furthermore, an UpToDate review on "Trigger finger (stenosing flexor tenosynovitis)" (Blazar and Aggarwal, 2019) does not mention thread trigger finger release as a therapeutic option.

Paulius and Maguina (2009) stated that trigger fingers can be treated by open or percutaneous division of the A1 pulley. The open approach allows for visualization of the pulley, the tendon, and the adjacent neurovascular bundles. The percutaneous trigger finger release (PTFR) lacks an incision and is thought to lead to a quicker recovery, but the safety and efficacy of this blind procedure are often questioned. Ultrasound (US) imaging has recently been introduced as an adjunct for guiding the needle during PTFR. This study was designed to examine the safety and efficacy of needle trigger finger release with added US imaging. A total of 18 fresh cadaver A1 pulleys were divided percutaneously and then evaluated by converting to an open technique and examining the pulleys, the tendons, and the neurovascular bundles. This study's US images demonstrated repeated puncture of the tendon sheath and of the neurovascular bundle during PTFR. The subsequent dissection revealed 3 out of 18 tendons with visible lacerations and 15 out of 18 A1 pulleys with incomplete division. The authors concluded that US-guided PTFR can be complicated by flexor tendon lacerations, potential injury to neurovascular bundles, and incomplete division of the A1 pulleys. These researchers stated that while the clinical significance of these findings was unclear, it raised questions regarding the safety and efficacy of PTFR, even when adding US guidance.

Rajeswaran et al (2009) evaluated a new technique for US-guided percutaneous release of the annular pulley in trigger digit using a modified hypodermic needle. A total of 35 US-guided percutaneous releases were performed on 25 patients diagnosed and referred by hand surgeons in the authors’ institution over 16 months from October 2006. Inclusion criteria were as follows: adulthood, triggering present for at least 4 months, failure to respond to conservative management or steroid injections, no previous history of pulley release in the affected digit. Under US guidance, the affected pulley was released using a standard 19-G hypodermic needle bent at 2 points as the cutting device. Follow-up took place at 12 weeks and 6 months with improvement in triggering and clinically graded pain. At follow-up, no complications had occurred and all patients demonstrated improvement in their triggering, with complete resolution in 32 digits (91 %), good improvement in 2 digits (6 %) and some improvement in 1 digit (3 %). The authors concluded that this new technique used a widely available and safe cutting device and was safe and could be used to provide definitive management for trigger finger, allowing the procedure to be performed in a variety of clinical settings.

Rojo-Manaute et al (2010) defined in volunteers a safe area for performing a percutaneous intra-sheath first annular (A1) pulley release under US guidance in cadavers for the treatment of trigger fingers. First, in 100 fingers of 10 volunteers, these researchers used Doppler US to determine the limits of the sectors enclosing structures at risk (arteries and tendons). From the synovial sheath's most volar point, these investigators determined the relative position of the arterial walls and the distance to the flexor tendons. A scatter-plot overlay of the arterial positions was digitally analyzed for determining the limits of the safe area. Second, these researchers released the A1 pulley in 46 fingers from 5 cadavers, directing the edge of the cutting device toward the safe area from an intra-sheath instrument position. The precision, safety, and efficacy of the release were evaluated by surgical exposure of the A1 and A2 pulleys and the neurovascular bundles. In the volunteers, these investigators observed a volar safe area from +6.1° to +180°. Surgical precision was good in the cadavers, with no injuries to adjacent structures, a complete release in 44 fingers (95.7 %), and an incomplete release of less than 1.6 mm in 2 fingers. The authors concluded that the findings of this study determined a safe volar area for aiming surgical instruments from an intra-sheath position for percutaneous US-guided A1 pulley release. The technique can be performed safely in all fingers, but these researchers suggested being cautious in the thumb and converting the surgery to an open procedure if US visualization is not optimal.

Hoang et al (2016) noted that trigger finger is the most common entrapment tendinopathy, with a lifetime risk of 2 % to 3 %. Open surgical release of the flexor tendon sheath is a commonly performed procedure associated with a high rate of success. Despite reported success rates of over 94 %, PFTR remains a controversial procedure because of the risk of iatrogenic digital neurovascular injury. These researchers examined the safety and efficacy of traditional percutaneous and US-guided A1 pulley releases performed on a perfused cadaveric model. First annular pulley releases were performed percutaneously using an 18-G needle in 155 digits (124 fingers and 31 thumbs) of un-embalmed cadavers with restored perfusion. A total of 45 digits were completed with US guidance and 110 digits were completed without it. Each digit was dissected and assessed regarding the amount of release as well as neurovascular, flexor tendon, and A2 pulley injury. Overall, 114 A1 pulleys were completely released (74 %). There were 38 partial releases (24 %) and 3 complete misses (2 %). No significant flexor tendon injury was observed. Longitudinal scoring of the flexor tendon was found in 35 fingers (23 %). There were no lacerations to digital nerves and 1 ulnar digital artery was partially lacerated (1 %) in a middle finger with a partial flexion contracture that prevented appropriate hyper-extension. The US-assisted and blind PTFR techniques had similar complete pulley release and injury rates. The authors concluded that both traditional and US-assisted percutaneous release of the A1 pulley can be performed for all fingers. Perfusion of cadaver digits enhanced surgical simulation and evaluation of PTFR beyond those of previous cadaveric studies. The addition of vascular flow to the digits during percutaneous release allowed for Doppler flow assessment of the neurovascular bundle and evaluation of vascular injury.

Appendix

Note on Documentation Requirements: CPT guidelines state that "Ultrasound guidance procedures also require permanently recorded images of the site to be localized, as well as a documented description of the localization process, either separately or within the report of the procedure for which the guidance is utilized. Use of ultrasound, without thorough evaluation of organ(s), or anatomic region, image documentation, and final, written report, is not separately reportable".

Table: CPT Codes / HCPCS Codes / ICD-10 Codes
Code	Code Description
*Information in the [brackets] below has been added for clarification purposes. Codes requiring a 7th character are represented by "+"* :
*Ultrasonic guidance for needle placement*:
CPT codes covered if selection criteria are met:
76942	Ultrasonic guidance for needle placement (eg, biopsy, aspiration, injection, localization device), imaging supervision and interpretation
76998	Ultrasonic guidance, intraoperative
CPT codes for procedures where 76942 and 76998 are covered if selection criteria are met: (not all inclusive)::
Piriformis muscle injection, Popliteal nerve block, Serratus plane block – no specific code::
20526	Injection, therapeutic (eg, local anesthetic, corticosteroid), carpal tunnel
20606	Arthrocentesis, aspiration and/or injection, intermediate joint or bursa (eg, temporomandibular, acromioclavicular, wrist, elbow or ankle, olecranon bursa); with ultrasound guidance, with permanent recording and reporting [scapular thoracic bursitis injection] [not covered for Iliopsoas bursa injection]
20611	Arthrocentesis, aspiration and/or injection, major joint or bursa (eg, shoulder, hip, knee, subacromial bursa); with ultrasound guidance, with permanent recording and reporting [scapular thoracic bursitis injection] [not covered for Iliopsoas bursa injection] [not covered for trochanteric bursa injection]
25000	Incision, extensor tendon sheath, wrist (eg, deQuervains disease)
27345	Excision of synovial cyst of popliteal space (eg, Baker's cyst)
31717	Catheterization with bronchial brush biopsy
32096	Thoracotomy, with diagnostic biopsy(ies) of lung infiltrate(s) (eg, wedge, incisional), unilateral
32097	Thoracotomy, with diagnostic biopsy(ies) of lung nodule(s) or mass(es) (eg, wedge, incisional), unilateral
32098	Thoracotomy, with biopsy(ies) of pleura
32400	Biopsy, pleura, percutaneous needle
32408	Core needle biopsy, lung or mediastinum, percutaneous, including imaging guidance, when performed
32607	Thoracoscopy; with diagnostic biopsy(ies) of lung infiltrate(s) (eg, wedge, incisional), unilateral
32608	with diagnostic biopsy(ies) of lung nodule(s) or mass(es) (eg, wedge, incisional), unilateral
32609	with biopsy(ies) of pleura
47000	Biopsy of liver, needle; percutaneous
+47001	when done for indicated purpose at time of other major procedure (List separately in addition to code for primary procedure)
47100	Biopsy of liver, wedge
48100	Biopsy of pancreas, open (eg, fine needle aspiration, needle core biopsy, wedge biopsy)
48102	Biopsy of pancreas, percutaneous needle
49180	Biopsy, abdominal or retroperitoneal mass, percutaneous needle
49321	Laparoscopy, surgical; with biopsy (single or multiple)
50040 - 50081	Incision, renal
50220 - 50240	Excision, renal
50384 - 50386	Introduction, renal
50390 - 50431, 50433, 50435	Other Introduction, renal
50541, 50543 - 50549	Laparoscopy, renal
50590 - 50593	Lithotripsy
55700	Biopsy, prostate; needle or punch, single or multiple, any approach
55705	incisional, any approach
58974	Embryo transfer, intrauterine
58976	Gamete, zygote, or embryo intrafallopian transfer, any method
60100	Biopsy thyroid, percutaneous core needle
62270	Spinal puncture, lumbar, diagnostic
62272	Spinal puncture, therapeutic, for drainage of cerebrospinal fluid (by needle or catheter)
62329	Spinal puncture, therapeutic, for drainage of cerebrospinal fluid (by needle or catheter); with fluoroscopic or CT guidance
62350	Implantation, revision or repositioning of tunneled intrathecal or epidural catheter, for long-term medication administration via an external pump or implantable reservoir/infusion pump; without laminectomy
62351	with laminectomy
62360	Implantation or replacement of device for intrathecal or epidural drug infusion; subcutaneous reservoir
62361	nonprogrammable pump
62362	programmable pump, including preparation of pump, with or without programming
64413	Injection, anesthetic agent; cervical plexus [Interscalene nerve block] and [Supraclavicular nerve block for post-operative pain control]
64415	brachial plexus, single [Interscalene nerve block] and [Supraclavicular nerve block for post-operative pain control]
64416	brachial plexus, continuous infusion by catheter (including catheter placement [Interscalene nerve block] and [Supraclavicular nerve block for post-operative pain control]
64417	Injection(s), anesthetic agent(s) and/or steroid; axillary nerve [Axillary brachial plexus nerve block]
64425	Injection(s), anesthetic agent(s) and/or steroid; ilioinguinal, iliohypogastric nerves
64445	sciatic nerve, single
64446	sciatic nerve, continuous infusion by catheter (including catheter placement) [not covered for gluteal nerve injection]
64447	femoral nerve, single arterial line placement [Fascia iliaca block for post-operative pain following hip and knee surgeries]
64448	femoral nerve, continuous infusion by catheter (including catheter placement) [Fascia iliaca block for post-operative pain following hip and knee surgeries]
64450	other peripheral nerve or branch [femoral nerve block for post-operative knee pain] and [quadratus lumborum nerve block for post-operative pain control after abdominal surgery] [lateral femoral cutaneous nerve block for meralgia paresthetica] [Pectoralis nerve block for the management of post-operative pain following mastectomy]
64486	Transversus abdominis plane (TAP) block (abdominal plane block, rectus sheath block) unilateral; by injection(s) (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
64487	by continuous infusion(s) (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
64488	Transversus abdominis plane (TAP) block (abdominal plane block, rectus sheath block) bilateral; by injections (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
64489	by continuous infusions (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
92928	Percutaneous transcatheter placement of intracoronary stent(s), with coronary angioplasty when performed; single major coronary artery or branch
+92929	each additional branch of a major coronary artery (List separately in addition to code for primary procedure)
92933	Percutaneous transluminal coronary atherectomy, with intracoronary stent, with coronary angioplasty when performed; single major coronary artery or branch
+92934	each additional branch of a major coronary artery (List separately in addition to code for primary procedure)
92937	Percutaneous transluminal revascularization of or through coronary artery bypass graft (internal mammary, free arterial, venous), any combination of intracoronary stent, atherectomy and angioplasty, including distal protection when performed; single vessel
+92938	each additional branch subtended by the bypass graft (List separately in addition to code for primary procedure)
92941	Percutaneous transluminal revascularization of acute total/subtotal occlusion during acute myocardial infarction, coronary artery or coronary artery bypass graft, any combination of intracoronary stent, atherectomy and angioplasty, including aspiration thrombectomy when performed, single vessel
92943	Percutaneous transluminal revascularization of chronic total occlusion, coronary artery, coronary artery branch, or coronary artery bypass graft, any combination of intracoronary stent, atherectomy and angioplasty; single vessel
+92944	each additional coronary artery, coronary artery branch, or bypass graft (List separately in addition to code for primary procedure)
92974	Transcatheter placement of radiation delivery device for subsequent coronary intravascular brachytherapy (List separately in addition to code for primary procedure)
CPT codes for procedures where 76942 and 76998 are not covered for indications listed in the CPB:
Erector spinae plane (ESP) block, Gluteal nerve injection, Hydro dissection of infrapatellar saphenous nerve, Iliotibial band hydro dissection, Lavage of the shoulder joint, Median nerve block, Trigger finger injection/trigger finger release without hydro dissection – no specific code:
0394T	High dose rate electronic brachytherapy, skin surface application, per fraction, includes basic dosimetry, when performed [superficial radiation treatment of skin cancer]
20550	Injection(s); single tendon sheath, or ligament, aponeurosis (eg, plantar "fascia") [iliopsoas tendon sheath] [medial calcaneal nerve sheath injection]
20551	Injection(s); single tendon origin/insertion [psoas tendon injection]
20552	single or multiple trigger point(s), 1 or 2 muscle(s)
20553	single or multiple trigger point(s), 3 or more muscles
26055	Tendon sheath incision (eg, for trigger finger) [Trigger finger injection/trigger finger release without hydro dissection]
36465	Injection of non-compounded foam sclerosant with ultrasound compression maneuvers to guide dispersion of the injectate, inclusive of all imaging guidance and monitoring; single incompetent extremity truncal vein (eg, great saphenous vein, accessory saphenous vein)
36466	multiple incompetent truncal veins (eg, great saphenous vein, accessory saphenous vein), same leg
36470	Injection of sclerosant; single incompetent vein (other than telangiectasia)
36471	multiple incompetent veins (other than telangiectasia), same leg
64405	Injection(s), anesthetic agent(s) and/or steroid; greater occipital nerve
64418	Injection(s), anesthetic agent(s) and/or steroid; suprascapular nerve [dorsal scapular nerve block]
64420	Injection, anesthetic agent; intercostal nerve, single
64421	intercostal nerves, multiple, regional block
64449	lumbar plexus, posterior approach, continuous infusion by catheter (including catheter placement)
64479	Injection(s), anesthetic agent and/or steroid, transforaminal epidural, with imaging guidance (fluoroscopy or CT); cervical or thoracic, single level
+64480	cervical or thoracic, each additional level (List separately in addition to code for primary procedure)
64483	lumbar or sacral, single level
+64484	lumbar or sacral, each additional level (List separately in addition to code for primary procedure)
64615	Chemodenervation of muscle(s); muscle(s) innervated by facial, trigeminal, cervical spinal and accessory nerves, bilateral (eg, for chronic migraine)
64616	Chemodenervation of muscle(s); neck muscle(s), excluding muscles of the larynx, unilateral (eg, for cervical dystonia, spasmodic torticollis)
77767	Remote afterloading high dose rate radionuclide skin surface brachytherapy, includes basic dosimetry, when performed; lesion diameter up to 2.0 cm or 1 channel [superficial radiation treatment of skin cancer]
77768	Remote afterloading high dose rate radionuclide skin surface brachytherapy, includes basic dosimetry, when performed; lesion diameter over 2.0 cm and 2 or more channels, or multiple lesions [superficial radiation treatment of skin cancer]
HCPCS codes for procedures where 76942 and 76998 are not covered for indications listed in the CPB:
J7318	Hyaluronan or derivative, durolane, for intra-articular injection, 1 mg
J7320	Hyaluronan or derivitive, genvisc 850, for intra-articular injection, 1 mg
J7321	Hyaluronan or derivative, Hyalgan, Supartz or Visco-3, for intra-articular injection, per dose
J7322	Hyaluronan or derivative, hymovis, for intra-articular injection, 1 mg
J7323	Hyaluronan or derivative, Euflexxa, for intra-articular injection, per dose
J7324	Hyaluronan or derivative, Orthovisc, for intra-articular injection, per dose
J7325	Hyaluronan or derivative, Synvisc, or Synvisc-One for intra-articular injection, 1 mg
J7326	Hyaluronan or derivative, Gel-One, for intra-articular injection, per dose
J7327	Hyaluronan or derivative, Monovisc, for intra-articular injection, per dose
J7328	Hyaluronan or derivative, for intra-articular injection, 0.1 mg [Gel-Syn]
*Ultrasound guidance for vascular access*:
CPT codes covered if selection criteria are met:
+76937	Ultrasound guidance for vascular access requiring ultrasound evaluation of potential access sites, documentation of selected vessel patency, concurrent realtime ultrasound visualization of vascular needle entry, with permanent recording and reporting (List separately in addition to code for primary procedure)
76998	Ultrasonic guidance, intraoperative
CPT codes for procedures where 76937 and 76998 are covered if selection criteria are met (not all inclusive):
36555	Insertion of non-tunneled centrally inserted central venous catheter; younger than 5 years of age
36556	age 5 years or older
36557	Insertion of tunneled centrally inserted central venous catheter, without subcutaneous port or pump; younger than 5 years of age
36558	age 5 years or older
36560	Insertion of tunneled centrally inserted central venous access device, with subcutaneous port; younger than 5 years of age
36561	age 5 years or older
36563	Insertion of tunneled centrally inserted central venous access device with subcutaneous pump
36565	Insertion of tunneled centrally inserted central venous access device, requiring 2 catheters via 2 separate venous access sites; without subcutaneous port or pump (eg, Tesio type catheter)
36566	with subcutaneous port(s)
36570	Insertion of peripherally inserted central venous access device, with subcutaneous port; younger than 5 years of age
36571	age 5 years or older
36575	Repair of tunneled or non-tunneled central venous access catheter, without subcutaneous port or pump, central or peripheral insertion site
36576	Repair of central venous access device, with subcutaneous port or pump, central or peripheral insertion site
36578	Replacement, catheter only, of central venous access device, with subcutaneous port or pump, central or peripheral insertion site
36580	Replacement, complete, of a non-tunneled centrally inserted central venous catheter, without subcutaneous port or pump, through same venous access
36581	Replacement, complete, of a tunneled centrally inserted central venous catheter, without subcutaneous port or pump, through same venous access
36582	Replacement, complete, of a tunneled centrally inserted central venous access device, with subcutaneous port, through same venous access
36583	Replacement, complete, of a tunneled centrally inserted central venous access device, with subcutaneous pump, through same venous access
36585	Replacement, complete, of a peripherally inserted central venous access device, with subcutaneous port, through same venous access
36589	Removal of tunneled central venous catheter, without subcutaneous port or pump
36590	Removal of tunneled central venous access device, with subcutaneous port or pump, central or peripheral insertion
50040 - 50081	Incision, renal
50220 - 50240	Excision, renal
50384 - 50386	Introduction, renal
50390 - 50431, 50433, 50435	Other Introduction, renal
50541, 50543 - 50549	Laparoscopy, renal
50590 - 50593	Lithotripsy

The above policy is based on the following references:

Ali M, Mohamed A, Ahmed HE, et al. The use of ultrasound-guided platelet-rich plasma injections in the treatment of hip osteoarthritis: A systematic review of the literature. J Ultrason. 2018;18(75):332-337.
Allison SK, Odderson IR. Ultrasound and electromyography guidance for injection of the longus colli with botulinum toxin for the treatment of cervical dystonia. Ultrasound Q. 2016;32(3):302-306.
Altıparmak B, Korkmaz Toker M,Uysal Aİ, et al. Comparison of the effects of modified pectoral nerve block and erector spinae plane block on postoperative opioid consumption and pain scores of patients after radical mastectomy surgery: A prospective, randomized, controlled trial. J Clin Anesth. 2019;54:61-65.
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Last Review 03/04/2021

Effective: 08/01/2019

Next Review: 10/28/2021
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