Aetna considers ultrasound of the spine and para-spinal tissues medically necessary in newborns and infants for the following indications:

• Detection of sequelae of injury (e.g., hematoma after spinal tap or birth injury; post-traumatic leakage of cerebrospinal fluid; and sequelae of prior instrumentation, infection, or hemorrhage).
• Evaluation of suspected defects such as cord tethering, diastematomyelia, hydromyelia, and syringomyelia.
• Guidance for lumbar puncture.
• Lumbosacral stigmata known to be associated with spinal dysraphism.
• Post-operative assessment for cord retethering.
• Spectrum of caudal regression syndrome (e.g., anal atresia or stenosis; sacral agenesis).
• Visualization of fluid with characteristics of blood products within the spinal canal in neonates and infants with intra-cranial hemorrhage.

Aetna considers ultrasound of the spine and para-spinal tissues medically necessary when performed intra-operatively.

Aetna considers diagnostic ultrasound of the spine and para-spinal tissues experimental and investigational for evaluation of neuromusculoskeletal conditions and all other indications (e.g., in the practice of neuraxial (epidural and subarachnoid) blocks, and to assist in lumbar puncture (except in newborns and infants)) because its effectiveness for these indications has not been established.

Aetna considers the SonixGPS (a real-time ultrasound-guided spinal anesthesia system) experimental and investigational because its effectiveness has not been established.

This policy is based on position statements of the American College of Radiology (ACR), and the American Academy of Neurology (AAN).

The ACR (1996) adopted the following statement on spinal ultrasound: “Over the past several years interest has developed in the use of ultrasound technology for the evaluation of the spine and paraspinal regions in adults.  While diagnostic ultrasound is appropriately used 1) intraoperatively; 2) in the newborn and infants for the evaluation of the spinal cord and canal; and 3) for multiple musculoskeletal applications in adults, there is currently no documented scientific evidence of the efficacy of this modality in the evaluation of the paraspinal tissues and the spine in adults.  Any claims or inferences that the use of spinal or paraspinal ultrasound is more advantageous or has a greater diagnostic accuracy than established procedures such as computed tomography (CT) or magnetic resonance imaging (MRI) cannot be made today based on recognized medical research.”

An AAN Report (1998) on spinal ultrasound for the evaluation of back pain and radicular disorders concluded: “Currently, no published peer reviewed literature supports the use of diagnostic ultrasound in the evaluation of patients with back pain or radicular symptoms.  The procedure cannot be recommended for use in the clinical evaluation of such patients.”

The American Institute of Ultrasound Medicine (AIUM, 2002) made the following official statement: “There is insufficient evidence in the peer-reviewed medical literature establishing the value of non-operative spinal/paraspinal ultrasound in adults.  Therefore, the AIUM states that, at this time, the use of non-operative spinal/paraspinal ultrasound in adults (for study of facet joints and capsules, nerve and fascial edema, and other subtle paraspinous abnormalities) for diagnostic evaluation, for evaluation of pain or radiculopathy syndromes, and for monitoring of therapy has no proven clinical utility.  Non-operative spinal/paraspinal ultrasound in adults should be considered investigational.  The AIUM urges investigators to perform proper double-blind research projects to evaluate the efficacy of these diagnostic spinal ultrasound examinations.”

Glotzbecker and colleagues (2009) noted that the risk of thrombo-embolic disease is well-studied for some orthopedic procedures.  However, the incidence of post-operative thrombo-embolic disease is less well-defined in patients who have had spinal surgery.  These investigators performed a systematic review on thrombo-embolic disease in spinal surgery.  The Medline database was queried using the search terms deep venous thrombosis or DVT, pulmonary embolus, thromboembolic disease, and spinal or spine surgery.  Abstracts of all identified articles were reviewed.  Detailed information from eligible articles was extracted.  Data were compiled and analyzed by simple summation methods when possible to stratify rates of DVT and/or pulmonary embolus for a given prophylaxis protocol, screening method, and type of spinal surgery.  A total of 25 articles were eligible for full review.  The risk of DVT ranged from 0.3 % to 31 %, varying between patient populations and methods of surveillance.  Pooling data from the 25 studies, the overall rate of DVT was 2.1 %.  The rate of DVT was influenced by prophylaxis method: no prophylaxis, 2.7 %; compression stockings (CS), 2.7 %; pneumatic sequential compression device (PSCD), 4.6 %; PSCD and CS, 1.3 %; chemical anti-coagulants, 0.6 %; and inferior vena cava filters with/without another method of prophylaxis, 22 %.  The rate of DVT was also influenced by the method of diagnosis, ranging from 1 % to 12.3 %.  The authors concluded that as risk of DVT after routine elective spinal surgery is fairly low, it seems reasonable to use CS with PSCD as a primary method of prophylaxis.  There is insufficient evidence to support or refute the use of chemical anti-coagulants in routine elective spinal surgery.  Furthermore, there is insufficient evidence to suggest that screening patients undergoing elective spinal surgery with ultrasound or venogram is routinely warranted.

Tsui and Suresh (2010) presented a comprehensive review of the evidence pertaining to techniques described and outcomes evaluated for ultrasound imaging in pediatric neuraxial anesthesia.  Neuraxial anesthesia pertains to local anesthetics placed around the nerves of the central nervous system, such as spinal anesthesia also called subarachnoid anesthesia and epidural anesthesia.  These researchers described and illustrated the anatomy related to each block to serve as a foundation for better understanding the block techniques described.  For neuraxial blockade, ultrasound may fairly reliably predict the depth to loss of resistance and can enable a dynamic view of the needle and catheter after entry into the spinal canal.  Particularly, in young infants, direct visualization of the needle and catheter tip may be possible, whereas in older children surrogate markers including the displacement of dura mater by the injection of fluid may be necessary for confirming needle and catheter placement.  The authors stated that more outcome-based, prospective, randomized, controlled trials are needed to prove the benefits of ultrasound when compared with conventional methods.

Perlas (2010) summarized the existing evidence behind the role of ultrasonography in neuraxial anesthesia techniques.  A literature search of the MEDLINE, PubMed, ACP Journal Club databases, and the Cochrane Database of Systematic Reviews was performed using the term ultrasonography combined with each of the following: spinal, intrathecal, epidural, and lumbar puncture.  Only studies related to regional anesthesia or acute pain practice were included.  Case reports and letters to the editor were excluded.  A total of 17 relevant studies were identified and included in this review.  Neuraxial ultrasonography is a recent development in regional anesthesia practice.  Most clinical studies to date come from a limited number of centers and have been performed by very few and highly experienced operators.  The existing evidence may be classified in 2 main content areas: (i) ultrasound-assisted neuraxial techniques and (ii) real-time ultrasound-guided neuraxial techniques.  The author concluded that neuraxial ultrasonography has been recently introduced to regional anesthesia practice.  The limited data available to date suggested that it is a useful adjunct to physical examination, allowing for a highly precise identification of regional landmarks and a precise estimation of epidural space depth, thus facilitating epidural catheter insertion.  Moreover, they stated that further research is needed to conclusively establish its impact on procedure success and safety profile, especially in the adult non-obstetric population.  This is in agreement with Tsui and Pillay (2010) who noted that although there is some evidence to support ultrasound for various outcomes in pediatric regional anesthesia, more randomized controlled studies with sufficient power are needed to further support these findings and to evaluate the potential for ultrasound to reduce complications for regional anesthesia in children.

Javanshir and colleagues (2010) reviewed the literature concerning size measurement of cervical muscles using real-time ultrasound imaging (RUSI) in patients with neck pain and in healthy populations.  A literature search from 1996 to December 2009 making use of Science Direct and PubMed databases was conducted.  Medical Subject Headings and other terms were as follows: ultrasonography, cervical, muscle, neck, size, pain, validity, reliability, neck pain, and healthy subjects.  These researchers included studies using RUSI for assessing cervical paraspinal muscles both in healthy subjects as well as in patients with neck pain.  They assessed muscles investigated and the reliability and validity of the method used.  The literature search yielded 16 studies -- 12 (75 %) studies assessed the posterior muscles, whereas in the remaining 4 (25 %), the anterior muscles were studied.  Three studies quantified the size of the muscles during contraction; 3 assessed the relationship between cross-sectional area, linear dimensions, and anthropometric variables; 1 evaluated the training-induced changes in muscle size; 1 assessed the differences in muscle shape and cross-sectional area of cervical multifidus between patients with chronic neck pain and controls; 8 studies looked at the reliability of using RUSI in patients with neck pain or healthy subjects; and 3 studies evaluated the validity of RUSI compared with magnetic resonance imaging.  The authors concluded that this literature review has shown that there are insufficient studies for assessing neck muscles with RUSI.  It seems that using constant landmarks, knowledge of anatomy and function of target muscle, and a proper definition of muscle borders can help to take a clear image.  Standardized position of the subject, correct placement of the transducer, and using multiple RUSI for statistical analyses may improve results.

The Work Loss Data Institute's clinical practice guideline on "Neck and upper back (acute & chronic)" (2011) listed diagnostic ultrasound as one of the interventions that was considered, but was not recommended.

The American Institute of Ultrasound in Medicine's practice guideline for the performance of an ultrasound examination of the neonatal spine (2012) states that this guideline has been developed to assist practitioners performing a sonographic examination of the neonatal and infant spine.  In some cases, an additional or specialized examination may be necessary.  While it is not possible to detect every abnormality, following this guideline will maximize the detection of abnormalities of the infant spine.  Sonographic examination of the pediatric spinal canal is accomplished by scanning through the normally incompletely ossified posterior elements.  Therefore, it is most successful in the newborn period and in early infancy.  In infants older than 6 months, the examination can be very limited, although the level of termination of the cord may be identified.  In experienced hands, ultrasound imaging of the infant spine has been shown to be an accurate and cost-effective examination that is comparable to magnetic resonance imaging for evaluating congenital or acquired abnormalities in the neonate and young infant.

The guideline lists the following indications for ultrasound examination of the neonatal spine:

• Detection of sequelae of injury (e.g., hematoma after spinal tap or birth injury; post-traumatic leakage of cerebrospinal fluid; and sequelae of prior instrumentation, infection, or hemorrhage).
• Evaluation of suspected defects such as cord tethering, diastematomyelia, hydromyelia, and syringomyelia.
• Guidance for lumbar puncture.
• Lumbosacral stigmata known to be associated with spinal dysraphism.
• Post-operative assessment for cord retethering.
• Spectrum of caudal regression syndrome (e.g., anal atresia or stenosis; sacral agenesis).
• Visualization of fluid with characteristics of blood products within the spinal canal in neonates and infants with intra-cranial hemorrhage.

Chin and Perlas (2011) stated that the use of ultrasound in lumbar plexus blockade has been described in the context of both pre-procedural imaging and real-time needle guidance; however, its clinical benefit in this setting has not yet been clearly established.  These investigators noted that pre-procedural ultrasound imaging of the spine may reduce the technical difficulty of neuraxial blockade and also improve clinical efficacy.  Similar benefits are expected in the setting of lumbar plexus blockade although there is currently no evidence to confirm this.  Moreover, they stated that real-time ultrasound-guided neuraxial and lumbar plexus blockade are challenging techniques that need further validation.

Wong and colleagues (2013) stated that the SonixGPS is an electromagnetic needle tracking system for ultrasound-guided needle intervention.  Both current and predicted needle tip position are displayed on the ultrasound screen in real-time, facilitating needle-beam alignment and guidance to the target.  This case report illustrated the use of the SonixGPS system for successful performance of real-time ultrasound-guided spinal anesthesia in a patient with difficult spinal anatomy.  A 67-year old male was admitted to the authors’ hospital to undergo revision of total right hip arthroplasty.  His 4 previous arthroplasties for hip revision were performed under general anesthesia because he had undergone L3 to L5 instrumentation for spinal stenosis.  The L4 to L5 interspace was viewed with the patient in the left lateral decubitus position.  A 19-G 80-mm proprietary needle (Ultrasonix Medical Corp, Richmond, BC, Canada) was inserted and directed through the para-spinal muscles to the ligamentum flavum in plane to the ultrasound beam.  A 120-mm 25-G Whitacre spinal needle was then inserted through the introducer needle in a conventional fashion.  Successful dural puncture was achieved on the second attempt, as indicated by a flow of clear cerebrospinal fluid.  The patient tolerated the procedure well, and the spinal anesthetic was adequate for the duration of the surgery.  The authors concluded that the SonixGPS is a novel technology that can reduce the technical difficulty of real-time ultrasound-guided neuraxial blockade.  It may also have applications in other advanced ultrasound-guided regional anesthesia techniques where needle-beam alignment is critical.