Transforaminal Epidural Injections

Number: 0722

Policy

  1. Aetna considers diagnostic selective transforaminal epidural steroid injections (TFESIs) with imaging guidance (fluoroscopy or CT) medically necessary for identifying the etiology of pain in persons with symptoms suggestive of chronic radiculopathy, where the diagnosis remains uncertain after standard evaluation (neurological examination, radiological and neurodiagnostic studies):

    1. To establish the diagnosis of radiculopathy, when pain appears to be due to classic mono-radiculopathy but radiological or neurodiagnostic studies fail to provide a structural explanation; or
    2. To establish the diagnosis of radiculopathy in a person with classic mono-radicular pain, in whom radiological studies demonstrate an abnormality related to an adjacent nerve root only; or
    3. For those cases in which the clinical picture is suggestive but not typical for both nerve root and distal nerve or joint disease.

    Aetna considers diagnostic TFESIs experimental and investigational for all other indications because its effectiveness other than the ones listed above has not been established.

  2. Aetna considers an initial therapeutic TFESI with imaging guidance (fluoroscopy or CT) medically necessary in the treatment of members with radiculopathy when non-invasive measures such as physical therapy and non-narcotic analgesics have failed or become intolerant, and the member has radicular pain that is consistent with radiologic findings.

    Additional therapeutic TFESIs with imaging guidance are considered medically necessary, if the initial injection resulted in at least two of the following for at least two weeks:

    1. A 50% or greater relief in pain
    2. Increase in the level of function/physical activity (e.g., return to work)
    3. Reduction in the use of pain medication and/or additional medical such as physical therapy/chiropractic care.

    Aetna considers therapeutic TFESIs experimental and investigational for all other indications because its effectiveness other than the ones listed above has not been established.

    Note: Therapeutic TFESIs should be administered as part of a comprehensive pain management program. 

    Aetna considers not medically necessary transforaminal epidural steroid injections (TFESIs) at more than two (2) contiguous vertebral levels or more than four (4) TFESIs [i.e., more than two (2) bilateral TFESIs at two (2) contiguous vertebral levels in the same spinal region (cervical, thoracic or lumbar)] during a single session.

    Aetna considers not medically necessary more than three (3) transforaminal epidural steroid injections (TFESI) sessions per episode of pain, per spinal region (cervical, thoracic or lumber) per six (6) months.  Note: For each TFESI session, up to four (4) TFESIs [i.e., two (2) bilateral TFESIs at two (2) contiguous vertebral levels in the same spinal region (cervical, thoracic or lumbar)] are considered medically necessary when other criteria are met.

    Aetna considers medically necessary a maximum of twelve (12) TFESIs per spinal region (cervical, thoracic or lumbar), administered during a maximum of three (3) sessions, for an episode of pain lasting six (6) months.

    Aetna considers not medically necessary more than four (4) sessions of TFESIs per spinal region (cervical, thoracic or lumbar) per twelve (12) months.  Note:  For each TFESI session, up to  four (4) TFESIs [i.e., two (2) bilateral TFESIs at two (2) contiguous vertebral levels in the same spinal region (cervical, thoracic or lumbar)] are considered medically necessary when other criteria are met.

    Aetna considers not medically necessary TFESI sessions more frequently than every two (2) weeks for all spinal regions (cervical, thoracic or lumbar).

  3. Aetna considers ultrasound-guided transforaminal epidural steroid injections experimental and investigational because their clinical effectiveness has not been established.

  4. Aetna considers transforaminal or interlaminar epidural steroid injections combined with caudal epidural steroid injections experimental and investigational for the treatment of chronic radicular pain because the effectiveness of this approach has not been established.

  5. Aetna considers TESI combined with radiofrequency ablation for the treatment of lumbar disc herniation experimental and investigational because the clinical effectiveness of this approach has not been established.

Note: For purposes of this policy, radiculopathy is defined as pain, dysaethesias, or paraesthesias in a specified dermatomal distribution of an involved named spinal roots causing significant functional limitations (i.e., diminished quality of life and impaired, age-appropriate activities of daily living), and either of the following:

  • Documentation of one or more of the following, concordant with nerve root compression of the involved named spinal roots demonstrated on a detailed neurologic examination within the prior three (3) months:

    • Loss of strength of specific named muscles or myotomal distributions; or
    • Altered sensation to light touch, pressure, pin prick or temperature in the sensory distribution; or
    • Diminished, absent or asymmetric reflexes; or

  • Documentation of either of the following performed within the prior 12 months:

    • A concordant radiologist’s interpretation of an advanced diagnostic imaging study (MRI or CT) of the spine demonstrating compression of the involved named spinal nerve roots; or
    • Electrodiagnostic studies (EMG/NCV’s) diagnostic of nerve root compression of the involved named spinal nerve roots.

For interlaminar epidural injections, see CPB 0016 - Back Pain - Invasive Procedures.

Background

Spinal nerve roots, arising from both sides of the spinal cord at each vertebral level, may be compressed or injured as a consequence of herniated discs, stenosis, facet cysts, whiplash, or hyper-extension injuries resulting in pain and inflammation.  In the management of patients with low back pain (LBP) and radiculopathy, selective transforaminal epidural injection, is a procedure used for both diagnostic (to ascertain whether a specific spinal nerve root is the source of pain) and therapeutic (to reduce inflammation around the spinal nerve root, thus reducing or relieving the pain) purposes.  Transforaminal epidural steroid injections are usually performed under fluoroscopic guidance; a needle is inserted into the epidural space in the foramen at the suspected spinal level, and medications such as steroids and local anesthetics are then injected into the area bathing the nerve root.  If a patient's pain improves following the injection, that nerve is likely the cause of the pain; otherwise the suspected nerve is probably not the source of the pain.  Although usually performed under fluoroscopy, computed tomography (CT) and CT fluoroscopy have been increasingly used to guide needle placement.  Use of intermittent CT fluoroscopy during lumbar TFESIs has been reported to result in minimal radiation dose levels and procedure times that are comparable to fluoroscopic guidance (Wagner et al, 2004).  While there is no definitive research to dictate the frequency of TFESIs, it is generally considered reasonable to limit TFESIs to 3 times per year (Spine-health.com, 2005).

Although epidural injections of steroids may produce the same effect, TFESIs are more focused injections that have better diagnostic value than epidural injections, especially in surgical planning.  When the two procedures are compared, injections of a large amount of steroid throughout the epidural space (i.e., epidural injections) are mostly of use when the pathology is located centrally in the spinal canal (e.g., central disk extrusion) or when 1 or 2 individual nerves can not be identified as the most likely source of the symptoms during physical examination or imaging studies.  Conventional epidural injection of steroids can be described as a “general” approach, covering many spinal levels but administering only a small amount of steroid at each level.  On the other hand, TFESI is more of a “target” approach, with the injection of a relatively large amount of steroid around a specific nerve root.  The latter approach is useful when 1 or 2 nerve roots are considered to be the likely source of the patient's pain (Wagner, 2005).

Diagnostic TFESI

Saal and colleagues (2002) reviewed the literature on diagnostic tests available to spine clinicians for the evaluation of chronic LBP.  These investigators stated that in a comparison of nerve root blockade, sciatic nerve block, posterior ramus block, and subcutaneous injection in a cohort of patients with sciatica, the sensitivity of nerve root block was very high, with only a moderate level of specificity.  Huston and Slipman (2002) stated that diagnostic TFESIs are useful in the diagnosis of radicular pain in atypical presentations.  These investigators stated that patients should have shown a failure to improve with less invasive treatment. In these patients, a diagnostic TFESI may localize the pain to a specific spinal nerve.  It must be emphasized that the diagnostic TFESI only determines if pain is emanating from a specific nerve root or spinal nerve.  A diagnostic TFESI does not determine what has caused the nerve root or spinal nerve pain, nor does it provide prognostic information.  The etiology of the nerve root pain, mechanism of injury, underlying anatomy, duration of symptoms, co-morbidities, patient desire, physician skill and a host of other factors determine the appropriate treatment and prognosis (Huston and Slipman, 2002).

Anderberg and colleagues (2004) described the method of a cervical diagnostic TFESI technique and assessed its ability to correlate clinical symptoms with MRI findings in patients with cervical radicular pain and a single level degenerative disease.  A total of 20 patients with cervical radiculopathy and correlating single level MRI pathology were studied.  All patients underwent clinical investigation as well as arm and neck pain measurements with visual analog scaleSNRBs (VAS).  The last 10 consecutive patients also underwent provocation with active neck motion when arm and neck pain were measured.  They all underwent TFESI and 1 ml local-anesthesia (mepivacaine 10 mg/ml) was injected, with the aid of fluoroscopy, close to the nerve-root.  The VAS estimation and clinical investigation including provocation were repeated 30 mins after the block.  Criteria for a positive block response were a significant subjective pain reduction and at least 50 % VAS pain reduction in the arm.  For the whole group, mean VAS arm pain reductions were 86 % and mean VAS neck pain reductions were 65 %.  When the results from the provocation were added, all patients had a positive block.  Eighteen patients were operated on by an anterior procedure and all 18 were free from radicular pain at follow-up.  These researchers concluded that TFESI seems relevant for revealing a relationship between radiological pathology and clinical symptoms and signs.  Furthermore, Anderberg et al (2005) also stated that TFESI might be a helpful tool together with clinical findings/history and MRI of the cervical spine when performing pre-operative investigations in patients with 2 or more level of degeneration presenting with radicular pain that can be attributed to the degenerative findings.

According to the Washington State Department of Labor and Industries' review criteria for cervical surgery for entrapment of a single nerve root (2004), a positive response to TFESI that correlates with imaging abnormality is needed if there are complaints of radicular pain with no motor, sensory, reflex, or electromyographic changes.  A TFESI may be considered “positive” if
  1. it initially produces pain in the distribution of the nerve root being blocked, and
  2. produces at least 75 % reduction in pain for a duration consistent with the type of local anesthetic used for the block.

In a review on TFESI for patients with LBP and radiculopathy, Gajraj (2004) stated that TFESI, when combined with a careful history, physical examination, and quality radiographical studies, is an important tool in the diagnostic evaluation of patients with predominantly radicular symptoms.  Diagnostic TFESIs are used to identify nerve roots responsible for pain when clinical or radiological studies are equivocal and for planning surgical treatment.  Indications for TFESI are as follows (Gajraj, 2004):

  • Anomalous innervations (e.g., conjoint nerve roots or furcal nerves)
  • Atypical extremity pain
  • Equivocal imaging studies
  • Equivocal neurological examinations
  • Failed back syndrome with atypical extremity pain
  • Temporary pain relief from a known cause of pain (e.g., disc herniation)
  • Transitional vertebrae.

Wagner (2005) stated that TFESI can help patients with symptoms related to a nerve root but who have no definite radiological diagnosis explaining the symptoms or who have so many abnormal MRI findings that confirming the origin of the symptoms is difficult.  In patients with uncertain pain etiology, TFESI is an effective and accurate means of determining if a certain nerve root is the source of the symptoms.

In the evidence-based practice guidelines on chronic spinal pain developed by the American Society of Interventional Pain Physicians, Boswell et al (2005) stated that the evidence was moderate for transforaminal epidural injections (or TFESIs) in the pre-operative evaluation of patients with negative or inconclusive imaging studies and clinical findings of nerve root irritation.  The guidelines also stated that epidural injections include the following routes:
  1. caudal,
  2. inter-laminar, and
  3. transforaminal.
In the diagnostic phase, a patient may receive two procedures at intervals of no sooner than 1 week or preferably, 2 weeks, except in cancer pain or when a continuous administration of local anesthetic is employed for reflex sympathetic dystrophy.

A systematic evidence review by Datta et al (2007) concluded that TFESIs may be helpful in the diagnosis of spinal pain with radicular features, but further research is required to clarify their role.  The systematic evidence review identified 8 studies that provided data on sensitivity and/or specificity of diagnostic TFESIs.  The sensitivity ranged from 87 to 100 % in 4 studies that included some form of surgery as the reference standard.  The authors reported that 1 study that used different blocks as the reference standard reported a much lower sensitivity of between 9 and 42 %.  This study also reported a low specificity of 24 %.  Four other studies that used surgery as part of the reference standard provided data on specificity; this ranged from 90 to 96 %.  The authors stated that further research is needed to investigate the accuracy of TFESIs in comparison with other established imaging and electrodiagnostic tests.  A critique of this systematic evidence review by the Centre for Reviews and Dissemination (2008) found that this review suffered from a number of limitations.  The CRD stated that the literature search by Datta et al was adequate for published studies, but unpublished studies were not sought and it is unclear whether any language restrictions were applied; thus, the review may therefore be subject to language and publication bias.  The CRD observed that a formal quality assessment was undertaken but the criteria used were for diagnostic accuracy studies; since only half of the included studies were diagnostic accuracy studies, these criteria were only appropriate for these studies.  In addition, the results of the quality assessment were simply presented as summary scores with no details of the individual items fulfilled; this has been shown to be inappropriate for the QUADAS criteria.  The CRD stated that the validity of the primary studies therefore remains unclear.  The CRD noted that Datta et al had taken steps to avoid error and bias in the selection of studies, but it is unclear if such steps were also taken for other stages of the review process.  Details of the included studies were tabulated clearly but did not always match up directly with the results reported in the text.  The CRD noted that synthesis of the results was very difficult to follow as the results of each individual study were simply described with very little attempt to synthesize them across studies.  The CRD stated that the lack of a synthesis of the results makes it difficult to comment on whether the authors' conclusions are supported by the data presented.

Therapeutic TFESI

Zennaro et al (1998) assessed the effectiveness of direct intra-foraminal steroid injections into the peri-ganglionic space in the treatment of patients with acute or chronic radicular pain (n = 41).  Neuroradiological imaging in all patients showed foraminal stenosis due to degenerative disorders or herniated disk.  All injections were performed under CT guidance.  A total of 70 % of patients had significant pain reduction, with the greatest success (90 % of patients) in those whose foraminal stenosis was due to degenerative disorders; 45 % of patients with foraminal herniated disks had pain relief.  These investigators concluded that intra-foraminal steroid injection is useful in the treatment of radicular pain, especially in cases of foraminal degenerative stenosis.

In a prospective, randomized, controlled, double-blind study, Riew et al (2000) examined the effectiveness of TFESI in obviating the need for an operation in patients with lumbar radicular pain who were otherwise considered to be operative candidates (n = 55).  Patients were randomized to undergo TFESI with either bupivacaine alone or bupivacaine with betamethasone.  The patients were allowed to choose to receive as many as four injections.  The treatment was considered to have failed if the patient proceeded to have the operation, which he or she could opt to do at any point in the study.  Twenty-nine of the 55 patients, all of whom had initially requested operative treatment, decided not to have the operation during the follow-up period (range of 13 to 28 months) after TFESI.  Of the 27 patients who had received bupivacaine alone, 9 (33.3 %) elected not to have the operation.  Of the 28 patients who had received bupivacaine and betamethasone, 20 (71.4 %) decided not to have the operation.  The difference in the operative rates between the 2 groups was highly significant (p < 0.004).  These researchers concluded that TFESI of corticosteroids are significantly more effective than those of bupivacaine alone in obviating the need for a decompression for up to 13 to 28 months following TFESIs in operative candidates.  This finding suggested that patients who have lumbar radicular pain at 1 or 2 levels should be considered for treatment with TFESI of corticosteroids prior to being considered for operative intervention.

In a retrospective study, Narozny and associates (2001) investigated the clinical effectiveness of nerve root blocks (i.e., peri-radicular injection of bupivacaine and triamcinolone) for lumbar mono-radiculopathy in patients with a mild neurological deficit.  These researchers analyzed 30 patients (aged 29 to 82 years) with a minor sensory/motor deficit and an unequivocal MRI finding (20 disc herniations, 10 foraminal stenoses) treated with a TFESI.  Based on the clinical and imaging findings, surgery (decompression of the nerve root) was justifiable in all cases.  Twenty-six patients (87 %) had rapid (1 to 4 days) and substantial regression of pain, 5 required a repeat injection.  Furthermore, 60 % of the patients with disc herniation or foraminal stenosis had permanent resolution of pain, so that an operation was avoided over an average of 16 months (6 to 23 months) follow-up.  The authors concluded that TFESIs are very effective in the non-operative treatment of minor mono-radiculopathy and should be recommended as the initial treatment of choice for this condition.

Pfirrmann et al (2001) studied TFESI for the treatment of patients with sciatica (n = 36).  These researchers concluded that therapeutic TFESI is effective in sciatica, but early response does not predict the effect after 2 weeks.

In a retrospective study, Slipman et al (2004) examined the outcomes resulting from the use of fluoroscopically guided therapeutic TFESI in the non-surgical treatment of traumatically induced cervical spondylotic radicular pain (n = 15).  The authors concluded that these findings do not support the use of therapeutic TFESI in the treatment of patients with traumatically induced spondylotic radicular pain.  On the other hand, Strobel et al (2004) reported that patients with foraminal disk herniation, foraminal nerve root compromise, and no spinal canal stenosis appear to have the greatest pain relief after cervical TFESIs (n = 60).

In a review on TFESI for LBP and radiculopathy, Gajraj (2004) stated that TFESI appears to be effective in the treatment of radicular pain especially when it is caused by an acute inflammatory process without irreversible changes in neural structure, and with duration of symptoms less than 1 year. 

DePalma and colleagues (2005) reviewed the evidence on the effectiveness of transforaminal epidural steroid injections (TFESI) or TFESIs to treat lumbosacral radiculopathy.  These investigators concluded that there is moderate evidence in support of TFESI in treating painful lumbar radicular symptoms.  The authors concluded that current studies support the use of TFESI/TFESI as a safe and minimally invasive adjunct treatment for lumbar radicular symptoms.  In a critique of the systematic evidence review by DePalma et al, the Centre for Reviews and Dissemination (2008) stated that relevant data might have been missed as only published English language studies were included in the review.  The CRD noted that the authors of this systematic review used published methods to assess the quality of the studies, but it is unclear how the studies were selected and how many reviewers performed the validity assessments; it is therefore difficult to assess the reliability, in terms of reviewer error or bias, of these review methods.  The CRD observed that it appears that one study was initially included in the review, but then subsequently excluded from the analysis as it was not a true randomized controlled clinical trial.  The CRD stated that, given the variability between the studies, in particular differences between the outcome measures and interventions, the authors' decision to use a narrative synthesis appears reasonable.  The authors also noted a number of design problems with the included studies: the lack of a true placebo-control group and the lack of a sham control group.  The studies were also limited in size, with only 2 studies having over 50 participants.  The CRD concluded that, "[g]iven the variability between the studies, the lack of appropriate controls, and the limited number of studies and participants, the authors' cautious conclusions appear reliable."

In a retrospective case series study with independent follow-up, Sabers et al (2005) assessed the success of fluoroscopically guided, contrast-enhanced lumbar zygapophyseal joint (Z-joint) aspiration and steroid injection combined with TFESI for the treatment of lumbar Z-joint cyst-induced radicular pain (n = 18).  Main outcome measures were patient satisfaction, and whether or not surgery was performed.  Fifty percent of patients treated with the procedure had significant long-term benefit and avoided surgical intervention at an average follow-up of 9.9 months.  These investigators concluded that fluoroscopically guided, contrast-enhanced spinal procedures as part of an aggressive non-surgical treatment program are a safe and effective alternative to surgical intervention for lumbar Z-joint cyst-induced radicular pain.

In a retrospective study, Blankenbaker and co-workers (2005) examined if there is a difference in the effectiveness of triamcinolone acetonide injectable suspension versus betamethasone sodium phosphate and betamethasone acetate injectable suspension in the treatment of radiculopathy and LBP with lumbar TFESIs.  Charts and self-reported pain score evaluations were reviewed in 114 patients who received 130 lumbar TFESIs with triamcinolone or betamethasone under fluoroscopic guidance.  Forty-nine patients received a mixture of 1 ml of the triamcinolone, 40 mg/ml, and 1 ml of 0.5 % bupivacaine hydrochloride; while 81 patients received a mixture of 1 ml of the betamethasone, 6 mg/ml, and 1 ml of 0.5 % bupivacaine hydrochloride.  From day 0 to 1 after the procedure, there was no statistically significant difference in improvement in LBP and lower extremity pain between groups.  On day 3, 42 % of triamcinolone recipients and 58 % of betamethasone recipients reported improvement in LBP (p = 0.04), whereas 55 % of triamcinolone recipients and 57 % of betamethasone recipients had lower extremity pain improvement (p = 0.33).  On day 7, 45 % of triamcinolone recipients and 58 % of betamethasone recipients had improvement in LBP (p = 0.38), whereas 52 % of triamcinolone recipients and 57 % of betamethasone recipients had improvement in lower extremity pain (p = 0.69).  On day 14, 42 % of triamcinolone recipients and 53 % of betamethasone recipients had improvement in LBP (p = 0.26), whereas 49 % of triamcinolone recipients and 55 % of betamethasone recipients had improvement in lower extremity pain (p = 0.69).  These investigators concluded that lumbar TFESIs with betamethasone and triamcinolone reduced LBP and lower extremity pain, although there was no significant difference in effectiveness between the 2 agents.

Wagner (2005) stated that TFESIs are useful in the following groups of individuals:
  1. patients after diskectomy who have recurrent radiculopathy but no recurrent disk herniation, symptoms are often caused when scar tissues tether the nerve.  Many patients can be treated successfully by using TFESI, although some may require a repeat injection, and
  2. patients with disk herniations.
Since the body naturally resolves 90 % of disk herniations when given enough time, pain relief is important to try to avoid surgery.

A technology assessment from the Institute for Clinical Systems Improvement (ICSI, 2004) found: “Fluoroscopically guided epidural steroid injections are generally safe when performed by an experienced physician in a controlled setting.  Epidural steroid injections should not be done without fluoroscopic guidance.  Commonly used corticosteroids include methylprednisolone and betamethasone.”  Regarding the evidence for transforaminal epidural injections, the ICSI Technology Assessment Committee concluded: “Based on limited data, the results appear promising.”

Choi and Brull (2011) evaluated the effect of ultrasound (US) guidance compared with traditional nerve localization techniques for interventional management of acute pain and acute pain-related outcomes.  These investigators performed a systematic search of Medline, Embase, and the Cochrane Central Register of Controlled Clinical Trials (from January 1990 to January 2011) to identify randomized controlled trials evaluating the effects of US guidance on acute pain and related outcomes compared with traditional nerve localization techniques.  Studies were excluded if they did not report at least one of the following acute pain outcomes: pain severity, opioid consumption, sensory block duration, and time to first analgesic request.  Related outcomes were classified as follows: patient related (opioid-related adverse effects, patient satisfaction, post-operative cognitive deficit); anesthesia related (unwanted motor block, perineural catheter failure, morbidity, development of chronic pain); surgery related (hospital readmission, ability to ambulate); and hospital-related (length of stay, cost).  Promising novel applications of US guidance for acute pain management were also sought for discussion purposes.  These researchers identified 23 randomized controlled trials, including 1,674 patients, that compared US guidance with and without peripheral nerve stimulation with peripheral nerve stimulation alone or anatomical landmark techniques.  Of the 16 studies that evaluated pain severity, 8 reported improvement with US guidance; however, only 1 study reported a difference between US guidance and the comparator of greater than 1 interval on the numeric rating pain scale.  Eight studies evaluated sensory block duration and 3 of these reported prolonged block duration with US guidance.  Seven studies evaluated opioid consumption, of which 3 reported a reduction with US guidance.  Three studies evaluated time to first analgesic request, of which 2 favored US guidance.  These investigators uncovered no significant differences between US guidance and traditional nerve localization techniques for any other related outcome.  Ultrasound guidance was not found to be inferior compared with traditional nerve localization techniques for any outcome.  The authors concluded that at present, there is insufficient evidence in the contemporary literature to define the effect of US guidance on acute pain and related outcomes compared with traditional nerve localization techniques for interventional acute pain management.

An UpToDate review on “Musculoskeletal ultrasonography: Guided injection and aspiration of joints and related structures” (Bruyn, 2014) does not mention transforaminal epidural injection as one of the techniques of US-guided injections.

In summary, the clinical value of a TFESI appears to rely on careful patient selection.  If it is carried out properly and the results are interpreted carefully, TFESI may be clinically useful, especially for those with insufficient diagnostic information.  In some cases, therapeutic effect can be achieved selectively at the symptomatic root.

Yang et al (2016) stated that recently, most lumbar spine injections have been administered under ultrasound guidance; however, there is no standard method for ultrasound-guided lumbar transforaminal epidural injection (TFEI).  In this study, these researchers evaluated the accuracy, effect on pain relief, and safety of ultrasound-guided lumbar TFEI.  A total of 80 patients with LBP and radicular pain were enrolled.  The subjects were randomly assigned to either the fluoroscopy group or the ultrasound group.  The fluoroscopy-guided approaches were performed under standardized procedures using the C-arm, while the ultrasound-guided injections were performed with an ultrasound device with a linear probe, and were verified by fluoroscopy.  The needle tip reached the lateral side of the lamina in the axis view and the middle of the adjacent facet joints in the para-sagittal view.  Afterward, the needle was advanced slightly deeper until the loss-of-resistance test was positive.  The success ratio of the ultrasound-guided interventions was 85 %.  The operation time in the ultrasound group (518 ± 103 s) was shorter than the fluoroscopy group (929 ± 228 s) (p < 0.05).  In addition, the radiation dosage in the ultrasound group (2,640 ± 906 μGy m) was lower than in the fluoroscopy group (8,992 ± 2,132 μGy m).  There was no significant difference in pain relief between the ultrasound and fluoroscopy groups.  No serious complication was observed by any of the subjects in either group.  The authors concluded that lumbar TFEI under ultrasound guidance was feasible, safe and required less radiation to achieve the same benefit as the fluoroscopy-guided interventions.  The main drawback of this study was that it was a feasibility and safety study.  The clinical effectiveness of TFEI needs to be ascertained in well-designed studies.

Manchikanti and associates (2015) determined the long-term effectiveness of cervical interlaminar epidural and TFE injections in the treatment of cervical disc herniation, spinal stenosis, discogenic pain without facet joint pain, and post-surgery syndrome. The literature search was performed from 1966 to October 2014 utilizing data from PubMed, Cochrane Library, US National Guideline Clearinghouse, previous systematic reviews, and cross-references.  The evidence was assessed based on best evidence synthesis with Level I to Level V.  There were 7 manuscripts meeting inclusion criteria.  Of these, 4 assessed the role of interlaminar epidural injections for managing disc herniation or radiculitis, and 3 assessed these injections for managing central spinal stenosis, discogenic pain without facet joint pain, and post-surgery syndrome.  There were 4 high quality manuscripts.  A qualitative synthesis of evidence showed there is Level II evidence for each etiology category.  The evidence was based on 1 relevant, high quality trial supporting the effectiveness of cervical interlaminar epidural injections for each particular etiology.  There were no randomized trials available assessing the effectiveness of cervical TFE injections.  The authors concluded that the findings of this systematic review with qualitative best evidence synthesis shows Level II evidence for the effectiveness of cervical interlaminar epidural injections with local anesthetic with or without steroids, based on at least 1 high-quality relevant randomized controlled trial (RCT) in each category for disc herniation, discogenic pain without facet joint pain, central spinal stenosis, and post-surgery syndrome.  The main drawback of this study was the paucity of available literature, specifically conditions other than disc herniation.

Kaye and co-workers (2015) evaluated and updated the clinical utility of the effectiveness of epidural injections in managing chronic spinal pain. These researchers performed a systematic review of RCTs of epidural injections in managing chronic spinal pain.  In this systematic review, randomized trials with a placebo control or an active-control design were included.  The outcome measures were pain relief and functional status improvement.  The quality of each individual article was assessed by Cochrane review criteria, as well as the Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB).  Best evidence synthesis was conducted based on the qualitative level of evidence (Level I to V).  Data sources included relevant literature identified through searches of PubMed for a period starting in 1966 through August 2015; Cochrane reviews; and manual searches of the bibliographies of known primary and review articles.  A total of 52 trials met inclusion criteria.  Meta-analysis was not feasible.  The evidence in managing lumbar disc herniation or radiculitis is Level II for long-term improvement either with caudal, interlaminar, or transforaminal epidural injections with no significant difference among the approaches.  The evidence is Level II for long-term management of cervical disc herniation with interlaminar epidural injections.  The evidence is Level II to III in managing thoracic disc herniation with an interlaminar approach.  The evidence is Level II for caudal and lumbar interlaminar epidural injections with Level III evidence for lumbar TFE injections for lumbar spinal stenosis.  The evidence is Level II for cervical spinal stenosis management with an interlaminar approach.  The evidence is Level II for axial or discogenic pain without facet arthropathy or disc herniation treated with caudal or lumbar interlaminar injections in the lumbar region; whereas it is Level II in the cervical region treated with cervical interlaminar epidural injections.  The evidence for post-lumbar surgery syndrome is Level II with caudal epidural injections and for post-cervical surgery syndrome it is Level II with cervical interlaminar epidural injections.  The authors concluded that the findings of this systematic review, with an assessment of the quality of manuscripts and outcome parameters, showed the effectiveness of epidural injections in managing a multitude of chronic spinal conditions.  Moreover, they stated that even though this was a large systematic review with inclusion of a large number of RCTs, the paucity of high-quality randomized trials literature continues to confound the evidence.

In a retrospective analysis, Costandi and colleagues (2015) evaluated the cervical TFESIs (CTFESIs) associated pain relief and possible decreased need for spine surgery, along with its potential predictive role in determining cervical surgical outcomes. Additionally, they estimated associated complications.  A pain management database registry was used to identify patients who were referred by spine surgeons for diagnostic CTFESIs in preparation for possible surgery between January 2001 and December 2009.  Outcomes were defined as the incidence of cervical surgery after diagnostic injection and the associated pain relief.  A Poisson distribution was used to obtain a 95 % confidence interval (CI) for the incidence of complications.  A total of 64 patients met the inclusion and exclusion criteria.  After diagnostic CTFESIs, 45 (70.3 %) of the observed 64 patients did not require cervical spine surgery whereas 19 (29.7 %) still did.  The mean pain reduction was 4.4 units on the numeric rating scale, with no observed complications.  The authors concluded that the findings of this retrospective analysis further demonstrated the safety, diagnostic value, and possible therapeutic role of CTFESIs.  They stated that a larger, controlled, randomized study is needed to assess definitively the procedure's safety and effectiveness.

Bhatia and colleagues (2016) noted that steroids often are administered into the epidural space through the TFE) route to treat lumbo-sacral radicular pain secondary to herniated intervertebral discs. However, their safety and effectiveness compared with transforaminal epidural local anesthetics (LAs) or saline injections is unclear.  These investigators reviewed RCTs that compared TFE injections of steroids (with or without LA) with LA or saline in adult outpatients with lumbosacral radicular pain secondary to herniated intervertebral disks.  Databases searched included Medline, Embase, Cochrane central register of controlled trials, Cochrane database of systematic reviews, and Google Scholar up to February 2015.  Data on scores of numerical rating scale for pain, validated scores for measuring physical disability and quality of life, and incidence of surgery measured at 1 month to 2 years after the interventions were meta-analyzed.  Strength of evidence was classified with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.  A total of 8 RCTs including 771 patients (366 in steroid and 405 in comparator groups) were included.  There was variability in the studies in the dose of TFE steroids, frequency, and number of procedures.  Patients who received TFE steroids reported a significant, but clinically modest, reduction in mean pain scores (0 to 10 scale) compared with LA/saline (-0.97 points; 95 % CI: -1.42 to -0.51 points; p < 0.0001, I² = 90 %; GRADE weak recommendation; moderate-quality evidence) at 3 months after the interventions; TFE steroids did not decrease physical disability at 1 to 3 months after the intervention (GRADE strong recommendation ↓; high-quality evidence) or incidence of surgery at 12 months after the intervention (GRADE strong recommendation ↓; moderate-quality evidence) compared with LA/saline.  The authors concluded that TFE steroids provided modest analgesic benefit at 3 months in patients with lumbosacral radicular pain secondary to herniated intervertebral disks, but they have no impact on physical disability or incidence of surgery.  There was a high degree of heterogeneity among the publications included in this meta-analysis.  They stated that well-designed, large, randomized studies are needed to evaluate appropriate dosages, adverse effects, number of procedures, and the effect of this intervention on psychological disability and quality of life.

Transforaminal Epidural Steroid injection Combined with Caudal Epidural Steroid Injection for the Treatment of Chronic Radicular Pain

There are 3 anatomical approaches (caudal, interlaminar, and transforaminal) to delivering corticosteroids into the epidural space.  Munjupong and Kumnerddee (2020) noted that ESI has been used in managing chronic radicular pain.  Regarding various techniques of ESI, the synergistic effect of caudal ESI (CESI) on TFESI in chronic lumbo-sacral radicular pain has not been determined in prospective RCT.  A total of 54 eligible patients with lumbo-sacral radicular pain were randomly allocated to undergo TFESI plus CESI (TC group) or TFESI alone (T group).  The effective response to treatment was pre-defined by at least a 50 % reduced verbal numerical rating scale (VNRS) from baseline between group comparison and the functional outcomes as measured by improved Oswestry Disability Index (ODI) by least 15 points from baseline.  All participants were evaluated using a single blinded outcome assessor before the procedure and at 1, 3 and 6 months after the procedure; p < 0.05 was considered as statistically significant.  Average VNRS reduced significantly from baseline after receiving procedure at 1, 3 and 6 months in both groups (p-value  of less than 0.05).  However, the TC group showed significant pain relief compared with the T group in spondylolisthesis and failed back surgery syndrome (FBSS) at 1 month.  No statistical difference was observed between group comparisons of functional outcomes.  The authors concluded that a treatment combining TFESI and CESI showed significant pain relief over TFESI alone in spondylolithesis and FBSS at 1 month.  No effect was found concerning functional evaluation.

The authors stated that this study had several drawbacks.  First, these researchers demonstrated radicular pain from symptomatology and physical examination, for which the source of pain may have overlapped the pain referred pattern from the zygapophyseal joint, sacroiliac joint pain or enclosing soft tissues, which might have limited the efficacy of the procedure.  However, many common problems are involved in chronic LBP.  Second, electro-diagnosis was not performed in this study.  Nonetheless, electro-diagnosis may have demonstrated false-negative findings, as demonstrated in a similar publication which showed 40 to 85 % sensitivity depending on the referral range.  Third, the study did not verify anterior or posterior epidural space of contrast flow, which might have affected the efficacy of the result.  Fourth, this study included a small sample size for subgroup allocation, which might not have been able to detect differences between groups.  A larger sample size in each etiology should be demonstrated in further study.  Lastly, these investigators did not collect the data of oral medication.  Further research is needed to examine if combination of oral medication, physiotherapy and psychological effect would influence the outcomes.

Evran and colleagues (2021) noted that recurrent lumbar disc herniation (RLDH) is one of the most common causes of chronic low back and leg pain.  Although surgical treatment has high success rates in primary LDHs, recurrence is not an uncommon clinic condition following surgery.  Considering the recurrent surgeries have lower success rates and higher risks, such as dural tear and nerve injury, alternative treatment modalities are needed for RLDH patients.  Epidural steroid injections (ESI), especially TFESI and(CESI, which are the alternative treatments to surgery, have not shown reasonable results in RLDH separately.  In a retrospective study, these investigators examined the effects of combined TFESI and CESI (TFESI + CESI) treatment, which has been found successful in primary LDH (PLDH) and on pain control and quality of life (QOL) in RLDH patients for the first time.  A total of 71 patients, who had ESI treatment as only TFESI or TFESI + CESI because of RLDH in the authors’ clinic between March 2017 and February 2020, were examined retrospectively.  The VAS leg, VAS back, and ODI were used to assess leg pain, LBP and limitation of daily routine activities.  Each assessment was conducted before the intervention and repeated at the 3rd week, the 3rd month, and the 6th month of injection, and the results were noted.  Out of 71 patients, 38 were women and 33 were men.  Patients were divided into 2 subgroups according to the applied ESI methods as only TFESI (n = 32) and TFESI + CESI (n = 39).  In the only TFESI group, the mean VAS leg score was 7.84, 4.63, 5.40, and 6.19 before, at the 3rd week, the 3rd month, and the 6th month of the injection, respectively.  Furthermore, in this group, the mean VAS back score was 8.06, 4.16, 4.88, and 5.97; the mean ODI score was 55.81, 34.31, 37.5, and 49.04 in the same respect.  In the TFESI + CESI group, the mean VAS leg score was 8.20, 2.87, 3.64, 4.23; mean VAS back score 8.03, 3.05, 3.90, 4.08; mean ODI score 56.56, 28.05, 30.21, 33.64 before, at the 3rd week, 3rd month, and 6th month of the injection, respectively.  The mean of the initial VAS leg, VAS back, and ODI scores was not found to be statistically significantly different between the 2 groups.  The mean of all VAS leg, VAS back, and ODI scores was found to be lower in the TFESI + CESI group than the only TFESI group at each 3rd-week, 3rd-month, and 6th-month controls, and these differences were statistically significant (p < 0.0001 at each controls for VAS leg; p = 0.001 at 3rd week, p = 0.002 at 3rd month and p <0.0001 at 6th month for VAS back; p = 0.0003 at 3rd week, p < 0.0001 at 3rd month, p < 0.0001 at 6th month for ODI).  The authors concluded that the findings of this study showed that TFESI + CESI treatment was an effective non-surgical treatment for RLDH.  These researchers stated that considering the higher risks and lower success rates of recurrent surgeries, TFESI + CESI can be a potential therapeutic option for RLDH patients.  Further studies are needed to validate these preliminary findings.

Fluoroscopically Guided Cervical Transforaminal Epidural Steroid Injection for the Treatment of Radicular Pain

In a systematic review and meta-analysis, Conger and colleagues (2020) examined the effectiveness of fluoroscopically guided cervical transforaminal epidural steroid injection (CTFESI) for the treatment of radicular pain.  Subjects were individuals aged greater than or equal to 18 years with cervical radicular pain due to disc herniation or degenerative spondylosis.  Comparisons entailed sham, placebo procedure, or active standard of care treatment, excluding alternative versions of epidural steroid injection.  The primary outcome measure was patient-reported improvement in pain of at least 50 % from baseline, evaluated 4 or more weeks after the treatment intervention.  Secondary outcomes included validated functional assessment tools and avoidance of spinal surgery.  Randomized or non-randomized comparative studies and non-randomized studies without internal control were included.  A total of 3 reviewers independently examined publications in the Medline, PubMed, and Cochrane databases up to July 2018.  The GRADE system was used to evaluate risk of bias and overall quality of evidence.  A meta-analysis was conducted for comparative measures of effect and for within-group response rates if applicable.  There were no studies with an internal comparison group (control group) meeting the review's definition of comparison group; thus, comparative measures of effect were not calculated.  In cohort studies, pooled response rates were 48 % (95 % CI: 34 % to 61 %) at 1 month and 55 % (95 % CI: 45 % to 64 %) at 3 months.  The authors concluded that approximately 50 % of patients experience greater than or equal to 50 % pain reduction at short- and intermediate-term follow-up after CTFESI.  However, the literature was very low quality according the GRADE criteria, primarily due to a lack of studies with placebo/sham or active standard of care control comparison groups.  These researchers stated that randomized trials with placebo/sham or non-CTFESI comparison groups are needed to determine the effectiveness and efficacy of CTFESI.

The authors stated that this study had 2 main drawbacks.  First, the study was conducted retrospectively.  Second, only 1 type of TFESI and CESI approach was applied to patients, variants of the TFESI and CESI application methods were not considered, and their individual results could not be evaluated.

Transforaminal Epidural Steroid Injection Combined with Radiofrequency Ablation for the Treatment of Lumbar Disc Herniation

In a retrospective study, Wei and colleagues (2021) examined the therapeutic effectiveness of TFESI combined with radiofrequency ablation (RFA) for the treatment of lumbar disc herniation (LDH).  A total of 230 patients participated in the study: TFESI (Group T, n = 110), TFESI combined with RFA (Group TR, n = 120); VAS, ODI and Global perceived effect (GPE) scale were measured pre-operation, 1, 3, 6, 12 and 24 months after the operation.  Hospitalization time, treatment time, complications, and recurrence were compared between the 2 groups.  The VAS and ODI at each observation point of the post-operation were significantly decreased compared with the pre-operation in both groups (p < 0.05).  There were no statistically difference of VAS and ODI between the 2 groups at 1 and 3 months of the post-operation (p > 0.05); however, The VAS and ODI scores in Group TR were significantly lower than that in Group T at 6, 12 and 24 months of the post-operation (p < 0.05).  The GPE in group TR was high in the early days, while that at 1 and 3 months after treatment was significantly higher than that in group T (p < 0.05).  The recurrence rate in Group TR was lower than that in Group T (p = 0.002).  There was no significant difference in hospitalization time, complications, VAS and ODI score at the pre-operation between the 2 groups (p > 0.05).   The authors concluded that the findings of this study suggested that TFESI combined with RFA could effectively improve the pain and function; and had a long-term satisfactory effect for the treatment of LDH.  Moreover, these researchers stated that larger scale clinical trials with multiple centers are needed in the future

The authors stated that this study had 2 main drawbacks.  First, this was a retrospective study; thus, there may be inherent bias associated with patient selection and missing patient information.  Second, the study was carried out in only 1 hospital with limited patients enrolled.

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 "+":

CPT codes covered if selection criteria are met:
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)

CPT codes not covered for indications listed in the CPB:
0228T Injections(s), anesthetic agent and/or steroid, transforaminal epidural, with ultrasound guidance, cervical or thoracic; single level
+0229T     each additional level (List separately in addition to code for primary procedure)
0230T Injections(s), anesthetic agent and/or steroid, transforaminal epidural, with ultrasound guidance, lumbar or sacral; single level
+0231T     each additional level (List separately in addition to code for primary procedure)
64635 Destruction by neurolytic agent, paravertebral facet joint nerve(s), with imaging guidance (fluoroscopy or CT); lumbar or sacral, single facet joint
64636      lumbar or sacral, each additional facet joint (List separately in addition to code for primary procedure)

Other CPT codes related to the CPB:
62320 - 62323 Injection(s), of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, including needle or catheter placement, interlaminar epidural or subarachnoid
62324 - 62327 Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, interlaminar epidural or subarachnoid
77003 Fluoroscopic guidance and localization of needle or catheter tip for spine or paraspinous diagnostic or therapeutic injection procedures (epidural or subarachnoid)
77012 Computed tomography guidance for needle placement (e.g., biopsy, aspiration, injection, localization device), radiological supervision and interpretation
97010 - 97530 Physical therapy

ICD-10 codes covered if selection criteria are met (not all-inclusive):
G56.00 - G57.93 Mononeuropathy of upper and lower limb
G58.0 - G58.7
G58.9		 Other mononeuropathies
M50.00 - M50.23
M50.90 - M50.93		 Cervical disc disorders
M51.04 - M51.27
M51.9		 Thoracic, thoracolumbar and lumbosacral intervertebral disc disorders
M54.10 - M54.18 Radiculopathy
M54.30 - M54.42 Sciatica and lumbago with sciatica
M79.2 Neuralgia and neuritis, unspecified

The above policy is based on the following references:

  1. Anderberg L, Annertz M, Brandt L, Saveland H. Selective diagnostic cervical nerve root block--correlation with clinical symptoms and MRI-pathology. Acta Neurochir (Wien). 2004;146(6):559-565; discussion 565.
  2. Anderberg L, Annertz M, Rydholm U, et al. Selective diagnostic nerve root block for the evaluation of radicular pain in the multilevel
    degenerated cervical spine. Eur Spine J. 2006;15(6):794-801.
  3. Bhatia A, Flamer D, Shah PS, Cohen SP. Transforaminal epidural steroid injections for treating lumbosacral radicular pain from herniated intervertebral discs: A systematic review and meta-analysis. Anesth Analg. 2016;122(3):857-870.
  4. Blankenbaker DG, De Smet AA, Stanczak JD, Fine JP. Lumbar radiculopathy: Treatment with selective lumbar nerve blocks--comparison of effectiveness of triamcinolone and betamethasone injectable suspensions. Radiology. 2005;237(2):738-741.
  5. Boswell MV, Shah RV, Everett CR, et al. Interventional techniques in the management of chronic spinal pain: Evidence-based practice guidelines. Pain Physician. 2005;8(1):1-47.
  6. Bruyn GAW. Musculoskeletal ultrasonography: Guided injection and aspiration of joints and related structures. UpToDate [serial online]. Waltham, MA: UpToDate; reviewed June 2014.
  7. Centre for Reviews and Dissemination (CRD). A critical appraisal of the evidence for selective nerve root injection in the treatment of lumbosacral radiculopathy. Database of Abstracts of Reviews of Effectiveness (DARE). York, UK: University of York; 2008.
  8. Centre for Reviews and Dissemination (CRD). An updated systematic review of the diagnostic utility of selective nerve root blocks. Database of Abstracts of Reviews of Effectiveness (DARE). York, UK: University of York; 2008.
  9. Choi S, Brull R. Is ultrasound guidance advantageous for interventional pain management? A review of acute pain outcomes. Anesth Analg. 2011;113(3):596-604.
  10. Chumnanvej S, Wetchagama N, Kounsongtham V. Accuracy of needle-tip localization by ultrasound guidance lumbar selective nerve root block: A prospective clinical study of 78 lumbar nerve roots block. J Med Assoc Thai. 2011;94(12):1451-1456.
  11. Conger A, Cushman DM, Speckman RA, et al. The effectiveness of fluoroscopically guided cervical transforaminal epidural steroid injection for the treatment of radicular pain; a systematic review and meta-analysis. Pain Med. 2020;21(1):41-54.
  12. Costandi SJ, Azer G, Eshraghi Y, et al. Cervical transforaminal epidural steroid injections: Diagnostic and therapeutic value. Reg Anesth Pain Med. 2015;40(6):674-680.
  13. Datta S, Everett CR, Trescot AM, et al. An updated systematic review of the diagnostic utility of selective nerve root blocks. Pain Physician. 2007;10(1):113-128.
  14. DePalma MJ, Bhargava A, Slipman CW. A critical appraisal of the evidence for selective nerve root injection in the treatment of lumbosacral radiculopathy. Arch Phys Med Rehabil. 2005;86(7):1477-1483.
  15. Evran S, Kayhan A, Baran O, et al. The synergistic effect of combined transforaminal and caudal epidural steroid injection in recurrent lumbar disc herniations.  Cureus. 2021;13(1):e12538.
  16. Gajraj NM. Selective nerve root blocks for low back pain and radiculopathy. Reg Anesth Pain Med. 2004;29(3):243-256.
  17. Huston CW, Slipman CW. Diagnostic selective nerve root blocks: Indications and usefulness. Phys Med Rehabil Clin N Am. 2002;13(3):545-565.
  18. Institute for Clinical Systems Improvement (ICSI). Fluoroscopically guided transforaminal epidural steroid injections for lumbar radicular pain. ICSI Technology Assessment Report No. 85. Bloomington, MN: ICSI; August 2004.
  19. Jonayed SA, Kamruzzaman M, Saha MK, et al. The role of selective nerve root block in the treatment of lumbar radicular leg pain. Mymensingh Med J. 2016;25(1):141-147.
  20. Kaye AD, Manchikanti L, Abdi S, et al. Efficacy of epidural injections in managing chronic spinal pain: A best evidence synthesis. Pain Physician. 2015;18(6):E939-E1004.
  21. Kumar N, Gowda V. Cervical foraminal selective nerve root block: A 'two-needle technique' with results. Eur Spine J. 2008;17(4):576-584.
  22. Manchikanti L, Abdi S, Atluri S, et al. An update of comprehensive evidence-based guidelines for interventional techniques in chronic spinal pain. Part II: Guidance and recommendations. Pain Physician. 2013;16(2 Suppl):S49-S283.
  23. Manchikanti L, Nampiaparampil DE, Candido KD, et al. Do cervical epidural injections provide long-term relief in neck and upper extremity pain? A systematic review. Pain Physician. 2015;18(1):39-60.
  24. Munjupong S, Kumnerddee W. Effect of supraneural transforaminal epidural steroid injection combined with caudal epidural steroid injection with catheter in chronic radicular pain management: Double blinded randomized controlled trial. F1000Res. 2020;9:634.
  25. Narouze SN, Vydyanathan A, Kapural L, et al. Ultrasound-guided cervical selective nerve root block: A fluoroscopy-controlled feasibility study. Reg Anesth Pain Med. 2009;34(4):343-348.
  26. Narozny M, Zanetti M, Boos N. Therapeutic efficacy of selective nerve root blocks in the treatment of lumbar radicular leg pain. Swiss Med Wkly. 2001;131(5-6):75-80.
  27. Oliveira CB, Maher CG, Ferreira ML, et al. Epidural corticosteroid injections for lumbosacral radicular pain. Cochrane Database Syst Rev. 2020;4(4):CD013577.
  28. Pfirrmann CW, Oberholzer PA, Zanetti M, et al. Selective nerve root blocks for the treatment of sciatica: Evaluation of injection site and effectiveness--a study with patients and cadavers. Radiology. 2001;221(3):704-711.
  29. Pobiel RS, Schellhas KP, Eklund JA, et al. Selective cervical nerve root blockade: Prospective study of immediate and longer term complications. AJNR Am J Neuroradiol. 2009;30(3):507-511.
  30. Riew KD, Park JB, Cho YS, et al. Nerve root blocks in the treatment of lumbar radicular pain. A minimum five-year follow-up. J Bone Joint Surg Am. 2006;88(8):1722-1725.
  31. Riew KD, Yin Y, Gilula L, et al. The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study. J Bone Joint Surg Am. 2000;82-A(11):1589-1593.
  32. Roberts ST, Willick SE, Rho ME, Rittenberg JD. Efficacy of lumbosacral transforaminal epidural steroid injections: A systematic review. PM R. 2009;1(7):657-668.
  33. Saal JS. General principles of diagnostic testing as related to painful lumbar spine disorders: A critical appraisal of current diagnostic techniques. Spine. 2002;27(22):2538-2545; discussion 2546.
  34. Sabers SR, Ross SR, Grogg BE, Lauder TD. Procedure-based nonsurgical management of lumbar zygapophyseal joint cyst-induced radicular pain. Arch Phys Med Rehabil. 2005;86(9):1767-1771.
  35. Slipman CW, Lipetz JS, DePalma MJ, Jackson HB. Therapeutic selective nerve root block in the nonsurgical treatment of traumatically induced cervical spondylotic radicular pain. Am J Phys Med Rehabil. 2004;83(6):446-454.
  36. Smith CC, McCormick ZL, Mattie R, et al. The effectiveness of lumbar transforaminal injection of steroid for the treatment of radicular pain: A comprehensive review of the published data. Pain Med. 2020;21(3):472-487.
  37. Spine-Health.com. Selective nerve root block (SNRB) for diagnosis and back pain management. Chicago, IL: Spine-Health.com; 2006. Available at: http://www.spine-health.com/topics/conserv/overview/inj/inj03.html. Accessed January 31, 2006.
  38. Stalcup ST, Crall TS, Gilula L, Riew KD. Influence of needle-tip position on the incidence of immediate complications in 2,217 selective lumbar nerve root blocks. Spine J. 2006;6(2):170-176.
  39. Strobel K, Pfirrmann CW, Schmid M, et al. Cervical nerve root blocks: Indications and role of MR imaging. Radiology. 2004;233(1):87-92.
  40. Tran K, Banks R. Epidural steroid injections to treat nonoperative lumbar radiculopathy: Clinical and cost-effectiveness and guidelines. Health Technology Inquiry Service (HTIS). Ottawa, ON: Canadian Agency for Drugs and Technologies in Health (CADTH); August 20, 2008.
  41. Wagner AL. Paraspinal Injections: Facet joint and nerve root blocks. eMedicine Radiology Topic 884. Omaha, NE: eMedicine.com; updated October 7, 2005.
  42. Wagner AL. Selective lumbar nerve root blocks with CT fluoroscopic guidance: Technique, results, procedure time, and radiation dose. AJNR Am J Neuroradiol. 2004;25(9):1592-1594.
  43. Washington State Department of Labor and Industries. Review criteria for cervical surgery for entrapment of a single nerve root. Olympia, WA: Washington State Department of Labor and Industries; June 2004.
  44. Wei W-B, Dang S-J, Wei L, et al. Transforaminal epidural steroid injection combined with radio frequency for the treatment of lumbar disc herniation: A 2-year follow-up. BMC Musculoskelet Disord. 2021;22(1):347.
  45. Wilby MJ, Best A, Wood E, et al. Surgical microdiscectomy versus transforaminal epidural steroid injection in patients with sciatica secondary to herniated lumbar disc (NERVES): A phase 3, multicentre, open-label, randomised controlled trial and economic evaluation. Lancet Rheumatol. 2021;3(5):e347-e356.
  46. Wolter T, Mohadjer M, Berlis A, Knoeller S. Cervical CT-guided, selective nerve root blocks: Improved safety by dorsal approach. AJNR Am J Neuroradiol. 2009;30(2):336-337.
  47. Yang G, Liu J, Ma L, et al. Ultrasound-guided versus fluoroscopy-controlled lumbar transforaminal epidural injections: A prospective randomized clinical trial. Clin J Pain. 2016;32(2):103-108.
  48. Yeom JS, Lee JW, Park KW, et al. Value of diagnostic lumbar selective nerve root block: A prospective controlled study. AJNR Am J Neuroradiol. 2008;29(5):1017-1023.
  49. Zennaro H, Dousset V, Viaud B, et al. Periganglionic foraminal steroid injections performed under CT control. AJNR Am J Neuroradiol. 1998;19(2):349-352.