Subject:
Image-Guided Minimally Invasive Decompression for Spinal Stenosis
Description:
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IMPORTANT NOTE:
The purpose of this policy is to provide general information applicable to the administration of health benefits that Horizon Blue Cross Blue Shield of New Jersey and Horizon Healthcare of New Jersey, Inc. (collectively “Horizon BCBSNJ”) insures or administers. If the member’s contract benefits differ from the medical policy, the contract prevails. Although a service, supply or procedure may be medically necessary, it may be subject to limitations and/or exclusions under a member’s benefit plan. If a service, supply or procedure is not covered and the member proceeds to obtain the service, supply or procedure, the member may be responsible for the cost. Decisions regarding treatment and treatment plans are the responsibility of the physician. This policy is not intended to direct the course of clinical care a physician provides to a member, and it does not replace a physician’s independent professional clinical judgment or duty to exercise special knowledge and skill in the treatment of Horizon BCBSNJ members. Horizon BCBSNJ is not responsible for, does not provide, and does not hold itself out as a provider of medical care. The physician remains responsible for the quality and type of health care services provided to a Horizon BCBSNJ member.
Horizon BCBSNJ medical policies do not constitute medical advice, authorization, certification, approval, explanation of benefits, offer of coverage, contract or guarantee of payment.
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Image-guided minimally invasive lumbar decompression (IG-MLD) describes a percutaneous procedure for decompression of the central spinal canal in patients with spinal stenosis and hypertrophy of the ligamentum flavum. In this procedure, a specialized cannula and surgical tools (mild®) are used under fluoroscopic guidance for bone and tissue sculpting near the spinal canal. IG-MLD is proposed as an alternative to existing posterior decompression procedures.
Populations | Interventions | Comparators | Outcomes |
Individuals:
- With lumbar spinal stenosis
| Interventions of interest are:
- Image-guided minimally invasive lumbar decompression
| Comparators of interest are:
- Conservative therapy
- Open decompression
| Relevant outcomes include:
- Symptoms
- Functional outcomes
- Health status measures
- Treatment-related morbidity
|
Individuals:
- With cervical or thoracic spinal stenosis
| Interventions of interest are:
- Image-guided minimally invasive cervical or thoracic decompression
| Comparators of interest are:
- Conservative therapy
- Open decompression
| Relevant outcomes include:
- Symptoms
- Functional outcomes
- Health status measures
- Treatment-related morbidity
|
BACKGROUND
Spinal Stenosis
In spinal stenosis, the space around the spinal cord narrows, compressing the spinal cord and its nerve roots. The goal of surgical treatment is to “decompress” the spinal cord and/or nerve roots.
The most common symptoms of lumbar spinal stenosis are back pain with neurogenic claudication (ie, pain, numbness, weakness) in the legs that worsens with standing or walking and is alleviated by sitting or leaning forward. Compression of neural elements generally occurs from a combination of degenerative changes, including ligamentum flavum hypertrophy, bulging of the intervertebral disc, and facet thickening with arthropathy. Spinal stenosis is often linked to age-related changes in disc height and arthritis of the facet joints. Lumbar spinal stenosis is among the most common reasons for back surgery and the most common reason for lumbar spine surgery in adults over the age of 65.
The most common symptoms of cervical/thoracic spinal stenosis are neck pain and radiculopathy of the shoulder and arm. The most common cause of cervical radiculopathy is degenerative changes, including disc herniation.
Treatment
Conventional Posterior Decompression Surgery
For patients with lumbar spinal stenosis, surgical laminectomy has established benefits in reducing pain and improving quality of life.
For patients with cervical or thoracic stenosis, surgical treatment includes discectomy or foraminal decompression.
A systematic review by Chou et al (2009) assessed surgery for back pain; it was commissioned by the American Pain Society and conducted by an evidence-based center.1,2, Four higher quality randomized trials were reviewed; they compared surgery with nonsurgical therapy for spinal stenosis, including two studies from the multicenter Spine Patient Outcomes Research Trial that evaluated laminectomy for spinal stenosis (specifically with or without degenerative spondylolisthesis).3,4, All 4 studies found that initial decompressive surgery (laminectomy) was slightly to moderately superior to initial nonsurgical therapy (eg, average 8- to 18-point differences on the 36-Item Short-Form Health Survey and Oswestry Disability Index). However, there was insufficient evidence to determine the optimal adjunctive surgical methods for laminectomy (ie, with or without fusion, instrumented vs noninstrumented fusion) in patients with or without degenerative spondylolisthesis. Spine Patient Outcomes Research Trial continues to be referenced as the highest quality evidence published on decompressive surgery.
Less invasive surgical procedures include open laminotomy and microendoscopic laminotomy. In general, the literature comparing surgical procedures is limited. The literature has suggested that less invasive surgical decompression may reduce perioperative morbidity without impairing long-term outcomes when performed in appropriately selected patients. Posterior decompressive surgical procedures include: decompressive laminectomy, hemilaminotomy and laminotomy, and microendoscopic decompressive laminotomy.
Decompressive laminectomy, the classic treatment for lumbar spinal stenosis, unroofs the spinal canal by extensive resection of posterior spinal elements, including the lamina, spinous processes, portions of the facet joints, ligamentum flavum, and the interspinous ligaments. Wide muscular dissection and retraction is needed to achieve adequate surgical visualization. The extensive resection and injury to the posterior spine and supporting musculature can lead to instability with significant morbidity, both postoperatively and longer term. Spinal fusion, performed at the same time as laminectomy or after symptoms have developed, may be required to reduce resultant instability. Laminectomy may also be used for extensive multilevel decompression.
Hemilaminotomy and laminotomy, sometimes termed laminoforaminotomy, are less invasive than laminectomy. These procedures focus on the interlaminar space, where most of the pathologic changes are concentrated, minimizing resection of the stabilizing posterior spine. A laminotomy typically removes the inferior aspect of the cranial lamina, superior aspect of the subjacent lamina, ligamentum flavum, and the medial aspect of the facet joint. Unlike laminectomy, laminotomy does not disrupt the facet joints, supra- and interspinous ligaments, a major portion of the lamina, or the muscular attachments. Muscular dissection and retraction are required to achieve adequate surgical visualization.
Microendoscopic decompressive laminotomy, similar to laminotomy, uses endoscopic visualization. The position of the tubular working channel is confirmed by fluoroscopic guidance, and serial dilators are used to dilate the musculature and expand the fascia. For microendoscopic decompressive laminotomy, an endoscopic curette, rongeur, and drill are used for the laminotomy, facetectomy, and foraminotomy. The working channel may be repositioned from a single incision for multilevel and bilateral dissections.
Image-Guided Minimally Invasive Lumbar Decompression
Posterior decompression for lumbar spinal stenosis has been evolving toward increasingly minimally invasive procedures in an attempt to reduce postoperative morbidity and spinal instability. Unlike conventional surgical decompression, the percutaneous mild® decompressive procedure is performed solely under fluoroscopic guidance (eg, without endoscopic or microscopic visualization of the work area). This procedure is indicated for central stenosis only, without the capability of addressing nerve root compression or disc herniation, should either be required.
Percutaneous image-guided minimally invasive lumbar decompression using a specially designed tool kit (mild®) has been proposed as an ultra-minimally invasive treatment of central lumbar spinal stenosis. In this procedure, the epidural space is filled with contrast medium under fluoroscopic guidance. Using a 6-gauge cannula clamped in place with a back plate, single-use tools (portal cannula, surgical guide, bone rongeur, tissue sculpter, trocar) are used to resect thickened ligamentum flavum and small pieces of lamina. The tissue and bone sculpting is conducted entirely under fluoroscopic guidance, with contrast media added throughout the procedure to aid visualization of the decompression. The process is repeated on the opposite side for bilateral decompression of the central canal. The devices are not intended for use near the lateral neural elements and are contraindicated for disc procedures.
Regulatory Status
In 2006, the X-Sten MILD Tool Kit now the mild® device kit (X-Sten Corp. renamed Vertos Medical) was cleared for marketing by the U.S. Food and Drug Administration through the 510(k) process for treatment of various spinal conditions. This set of specialized surgical instruments is used to perform percutaneous lumbar decompressive procedures.
Vertos’s mild® instructions state that the device is not intended for disc procedures but rather for tissue resection at the perilaminar space, within the interlaminar space, and at the ventral aspect of the lamina. The device is not intended for use near the lateral neural elements and remains dorsal to the dura using image guidance and anatomic landmarks.
Food and Drug Administration product code: HRX.
Related Policies
- Interspinous and Interlaminar Stabilization/Distraction Devices (Spacers) (Policy #065 in the Surgery Section)
Policy:
(NOTE: For Medicare Advantage, please refer to the Medicare Coverage Section below for coverage guidance.)
Image-guided minimally invasive spinal decompression is considered investigational.
Medicare Coverage:
CMS has determined that percutaneous image guided lumbar decompression (PILD) for lumbar spinal stenosis (LSS) is not reasonable and necessary under section 1862(a)(1)(A) of the Social Security Act. However, CMS has also decided that PILD (CPT codes 0275T and G0276) will be covered by Medicare through Coverage with Evidence Development (CED) for beneficiaries with LSS who are enrolled in an approved clinical study that meets the CMS criteria. For criteria, study protocols and design refer to National Coverage Determination (NCD) for Percutaneous image-guided lumbar decompression for lumbar spinal stenosis 150.13. NCD 150.13 available to be accessed at CMS National Coverage Determinations (NCDs) Alphabetical Index search page: https://www.cms.gov/medicare-coverage-database/indexes/ncd-alphabetical-index.aspx
[RATIONALE: This policy was created in 2010 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through January 30, 2020.
Evidence reviews assess the clinical evidence to determine whether the use of technology improves the net health outcome. Broadly defined, health outcomes are the length of life, quality of life, and ability to function, including benefits and harms. Every clinical condition has specific outcomes that are important to patients and managing the course of that condition. Validated outcome measures are necessary to ascertain whether a condition improves or worsens; and whether the magnitude of that change is clinically significant. The net health outcome is a balance of benefits and harms.
To assess whether the evidence is sufficient to draw conclusions about the net health outcome of technology, two domains are examined: the relevance, and quality and credibility. To be relevant, studies must represent one or more intended clinical use of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. For some conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence depend on study design and conduct, minimizing bias and confounding that can generate incorrect findings. The randomized controlled trial (RCT) is preferred to assess efficacy; however, in some circumstances, nonrandomized studies may be adequate. RCTs are rarely large enough or long enough to capture less common adverse events and long-term effects. Other types of studies can be used for these purposes and to assess generalizability to broader clinical populations and settings of clinical practice.
Image-Guided Minimally Invasive Lumbar Decompression
This policy addresses posterior decompression of lumbar spinal stenosis with percutaneous treatment performed under fluoroscopic guidance. The primary literature on image-guided minimally invasive lumbar decompression includes a large RCT (n=302) that is ongoing, a small RCT (n=38), and a number of prospective and retrospective cohort studies and case series.
Review of Evidence
Randomized Controlled Trials
The protocol for the MiDAS ENCORE (Evidence-based Neurogenic Claudication Outcomes Research) trial (NCT02093520) was approved by the Centers for Medicare & Medicaid Services under coverage with evidence development. This nonblinded study, conducted at 26 interventional pain management centers in the U.S., randomized 302 patients in a 1:1 ratio to image-guided minimally invasive lumbar decompression or epidural steroid injections.5, This trial included Medicare beneficiaries 65 years or older who had neurogenic claudication symptoms for at least 3 months and had failed standard therapies, including physical therapy, home exercise programs, and oral analgesics.
Selection criteria required radiologic evidence of lumbar spinal stenosis with ligamentum flavum greater than 2.5 mm confirmed by preoperative magnetic resonance imaging or computed tomography. Patients had a number of spinal stenosis cofactors in addition to ligamentum flavum hypertrophy, including bulging disc (91%), foraminal narrowing (88%), facet hypertrophy (84%), facet arthropathy (82%), and degenerative disc disease (71%), that could not be addressed by the image-guided minimally invasive lumbar decompression technique.
Baseline scores were similar in both groups (see Table 1). However, more patients in the epidural steroid injection group withdrew prior to trial treatment (22 patients vs 6 patients) due to dissatisfaction with randomization results and decisions to have surgery or other nonstudy therapy. This unequal dropout rate would suggest risk of bias due to nonblinding of patients and assessors and patient expectations. Patients who withdrew from the trial after treatment but before the 1-year follow-up (22 image-guided minimally invasive lumbar decompression, 32 epidural steroid injections) were considered treatment failures.
Six-month and 1-year results were published in 2016 (see Table 1).5,6, Patients in the epidural steroid injection group were allowed up to four epidural steroid injection treatments and received a mean of 2 injections over one year. The primary endpoint the proportion of responders achieving the minimally important difference of at least a 10-point improvement on the Oswestry Disability Index score was significantly higher in the image-guided minimally invasive lumbar decompression group than in the epidural steroid injection group at both 6 months and 1 year. Secondary efficacy endpoints were the proportion of responders achieving the minimally important difference on the numeric rating scale for pain and the Zurich Claudication Questionnaire. Adverse events were low (1.3% for both groups). Responder rates in patients with spinal comorbidities were reported to be similar to overall responder rates. However, it may be difficult to separate out the effect of comorbidities, because over 80% of patients had 1 or more spinal stenosis comorbidities.
Two-year follow-up data for patients treated with image-guided minimally invasive lumbar decompression in the MiDAS ENCORE trial was published in 2018.7, Follow-up data was available for 69% of study participants and is summarized in Table 1. Comparative data for the epidural steroid injection cohort was not reported.
Study relevance, design, and conduct limitations are summarized in Table 2 and 3.
Table 1. MiDAS ENCORE* Results
Outcomes | Baseline Score, Mean (SD) | Percent Response at 6 Months, % | Percent Response at 1 Year, % | Percent Response (%) and Mean Improvement at 2 Years (95% CI) |
Pain (NRS)1 | N=143 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=99 (IG-MD) |
IG-MLD | 7.7 (1.4) | 55.9** | 57.3** | 71.73.6 (3.1 to 4.2) |
ESI | 7.8 (1.3) | 33.3 | 27.1 | NR |
Disability (ODI)2 | N=143 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=98 (IG-MLD) |
IG-MLD | 53.0 (12.9) | 62.2** | 58.0** | 72.422.7 (18.5 to 26.9) |
ESI | 51.7 (12.0) | 35.7 | 27.1 | NR |
ZCQ: Symptom Severity3 | N=142 (IG-MLD)N=129 (ESI) | N=142 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=98 (IG-MLD) |
IG-MLD | Pain: 3.8 (0.5)Neuroischemic: 3.2 (0.9) | 52.8** | 51.7* | 73.51.0 (0.8 to 1.2) |
ESI | Pain: 3.8 (0.5)Neuroischemic: 3.2 (0.8) | 28.7 | 31.8 | NR |
ZCQ: Physical Function3 | N=143 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=98 (IG-MLD) |
IG-MLD | 2.9 (0.5) | 52.4** | 44.1** | 59.60.8 (0.6 to 0.9) |
ESI | 2.8 (0.4) | 14.0 | 17.8 | NR |
ZCQ: Patient Satisfaction3 | N=142 (IG-MLD)N=129 (ESI) | N=142 (IG-MLD)N=129 (ESI) | N=143 (IG-MLD)N=129 (ESI) | N=98 (IG-MLD) |
IG-MLD | NA | 64.8** | 61.5** | 76.82.0 (1.8 to 2.2) |
ESI | NA | 30.2 | 33.3 | NR |
* MiDAS ENCORE: Evidence-based Neurogenic Claudication Outcomes Research trial.6,7,
ESI: epidural steroid injection; IG-MLD: image-guided minimally invasive lumbar decompression; NA: not applicable; NRS: Numeric Rating Scale; ODI: Oswestry Disability Index; ZCQ: Zurich Claudication Questionnaire.
1 Pain score as determined with the Numerical Rating Scale, with 0 reflecting no pain and 10 reflecting worst possible pain. A positive response was defined by a ≥2-point improvement in score.
2 Disability score as determined with the Oswestry Disability Index (0-100), with a score of 0-20 reflecting minimal disability, a score of 21-40 reflecting moderate disability, and a score of 41-60 reflecting severe disability.
A positive response was defined with an improvement (decrease) of 10 or more points as determined by the the Minimally Important Change (MIC).
3 Pain symptom severity, physical function, and patient satisfaction with the procedure was assessed with relevant subdomains of the Zurich Claudication Questionnaire. Lower scores indicate better health status or higher patient satisfaction with treatment.
A ≥0.5-point improvement in ZCQ subdomain scores denotes a MIC and defines a positive response. Patient satisfaction
scores are only assessed post-treatment.
** p < 0.001
* p = 0.001
Table 2. Study Relevance Limitations
Study | Populationa | Interventionb | Comparatorc | Outcomesd | Follow-Upe |
MiDAS ENCORE (2016, 2018)6,7, | 4. Study population had a significantly high proportion of patients with comorbidities that the intervention was not designed to address. |  | 3. Delivery not similar intensity as intervention. |  | 1-2. Follow-up data at two years not reported for comparator. |
The study limitations stated in this table are those notable in the current review; this is not a comprehensive limitations assessment.
a Population key: 1. Intended use population unclear; 2. Clinical context is unclear; 3. Study population is unclear; 4. Study population not representative of intended use.
b Intervention key: 1. Not clearly defined; 2. Version used unclear; 3. Delivery not similar intensity as comparator; 4. Not the intervention of interest.
c Comparator key: 1. Not clearly defined; 2. Not standard or optimal; 3. Delivery not similar intensity as intervention; 4. Not delivered effectively.
d Outcomes key: 1. Key health outcomes not addressed; 2. Physiologic measures, not validated surrogates; 3. No CONSORT reporting of harms; 4. Not established and validated measurements; 5. Clinical significant difference not prespecified; 6. Clinical significant difference not supported.
e Follow-Up key: 1. Not sufficient duration for benefit; 2. Not sufficient duration for harms.
Table 3. Study Design and Conduct Limitations
Study | Allocationa | Blindingb | Selective Reportingc | Data Completenessd | Powere | Statisticalf |
MiDAS ENCORE (2016, 2018)6,7, | 3. Allocation concealment unclear. | 1. Not blinded to treatment assignment. |  | 1. High loss to follow-up or missing data. | 1. Power calculations not clearly reported.
2. Power not calculated for primary outcome.
3. Not clear if power calculations were based on clinically important difference(s). | 3. Confidence intervals and/or p values not reported for all outcome measures.
4. Comparative treatment effects not reported for two year follow-up. |
The study limitations stated in this table are those notable in the current review; this is not a comprehensive limitations assessment.
a Allocation key: 1. Participants not randomly allocated; 2. Allocation not concealed; 3. Allocation concealment unclear; 4. Inadequate control for selection bias.
b Blinding key: 1. Not blinded to treatment assignment; 2. Not blinded outcome assessment; 3. Outcome assessed by treating physician.
c Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication.
d Data Completeness key: 1. High loss to follow-up or missing data; 2. Inadequate handling of missing data; 3. High number of crossovers; 4. Inadequate handling of crossovers; 5. Inappropriate exclusions; 6. No intent to treat analysis (per protocol for noninferiority trials).
e Power key: 1. Power calculations not reported; 2. Power not calculated for primary outcome; 3. Power not based on clinically important difference.
f Statistical key: 1. Analysis is not appropriate for outcome type: (a) continuous; (b) binary; (c) time to event; 2. Analysis is not appropriate for multiple observations per patient; 3. Confidence intervals and/or p values not reported; 4. Comparative treatment effects not calculated.
Systematic Reviews
Prior to publication of MiDAS ENCORE trial results, the International Spine Intervention Society published a systematic review of the image-guided minimally invasive lumbar decompression literature.8, Included were an RCT with 38 patients9, and 12 cohort studies or series. Pain measurements, using a visual analog score or the Zurich Claudication Questionnaire, showed a weighted mean improvement of 41% in the short term (4-6 weeks), 46% at 3 months, 42% at 6 months, and 49% at 1 year. However, mean visual analog score scores exceeded 3 at all times posttreatment. Ten studies assessed function, nine using the Oswestry Disability Index or one using the Roland-Morris Disability Questionnaire. Oswestry Disability Index scores improved by a weighted mean of 16.5 at 6 weeks, 16.2 at 12 weeks, 15.4 at 6 months, and 14.0 at 1 year, a weighted cumulative decline to 33 from 47 at baseline. The study by Chopko (2013), reporting 2-year outcomes, was of questionable validity, and data were not included.10, Mean final Oswestry Disability Index scores exceeded 30 for most studies, which would not be considered in the normal range. No direct procedure-related complications were identified in the selected studies, although the possibility of damage to dura and nerve roots with this procedure was noted. Overall, the body of evidence addressing the image-guided minimally invasive lumbar decompression procedure was of low quality.
Case Series
One potential indication for image-guided minimally invasive lumbar decompression is patients with symptomatic lumbar spinal stenosis primarily caused by a hypertrophic ligamentum flavum who are considered poor candidates for traditional decompressive surgery.
Chopko (2011) also reported on image-guided minimally invasive lumbar decompression in 14 patients considered at high-risk for complications from open spine surgery and general anesthesia.11, Comorbidities included obesity, diabetes, hypertension, chronic obstructive pulmonary disease, chemotherapy, and coronary artery disease. Postoperatively, 9 (64%) of the 14 patients reported improvement in visual analog score pain scores of at least 3 points. Oswestry Disability Index scores did not change significantly. A retrospective review by Lingreen and Grider (2010) reported on outcomes of a consecutive series of 42 patients who underwent image-guided minimally invasive lumbar decompression by an interventional pain specialist.12, Most patients had not been considered surgical candidates by a spine surgeon. visual analog score pain scores averaged 9.6 at baseline and 5.8 at 30 days postprocedure, with 34 (80%) of patients reporting changes in visual analog score of 3 or more points. Thirty (71%) patients reported improvements in function following image-guided minimally invasive lumbar decompression. No major adverse events were identified.
Section Summary: Image-Guided Minimally Invasive Lumbar Decompression
The evidence on the use of image-guided minimally invasive lumbar decompression to treat lumbar spinal stenosis or cervical/thoracic spinal stenosis consists of a large, ongoing RCT (n=302), a systematic review of a small RCT (n=38), and a number of prospective and retrospective cohort studies and case series. The largest RCT compared image-guided minimally invasive lumbar decompression with epidural steroid injections (control) in patients with ligamentum flavum hypertrophy and who failed conservative therapy. Early results have suggested reductions in pain and improvements in function scores in the image-guided minimally invasive lumbar decompression group vs the control group. The trial was unblinded and there is evidence of differing expectations and follow-up in both groups, suggesting a high-risk of bias. The available evidence is insufficient to determine the efficacy of mild® compared with placebo or to determine the efficacy of image-guided minimally invasive lumbar decompression compared with open decompression. Trials with relevant control groups could provide greater certainty on the risks and benefits of this procedure.
Image-Guided Minimally Invasive Cervical or Thoracic Decompression
No evidence assessing use of image-guided minimally invasive cervical or thoracic decompression for treatment of patients with cervical or thoracic spinal stenosis was found.
Section Summary: Image-Guided Minimally Invasive Cervical or Thoracic Decompression
There is no evidence to inform conclusions about use of image-guided minimally invasive cervical or thoracic decompression to treat cervical or thoracic spinal stenosis.
Summary of Evidence
For individuals who have lumbar spinal stenosis, or cervical or thoracic spinal stenosis who receive image-guided minimally invasive lumbar decompression, the evidence includes a large, ongoing randomized controlled trial (n=302), a systematic review of a small randomized controlled trial (n=38), and a number of prospective and retrospective cohort studies and case series. Relevant outcomes are symptoms, functional outcomes, health status measures, and treatment-related morbidity. The largest randomized controlled trial compared image-guided minimally invasive lumbar decompression with epidural steroid injections (control) in patients who had ligamentum flavum hypertrophy and who failed conservative therapy. Early results have suggested reductions in pain and improvements in function scores in the image-guided minimally invasive lumbar decompression group vs the control group. The trial was unblinded and there is evidence of differing expectations and follow-up in the 2 groups, suggesting a high-risk of bias. The available evidence is insufficient to determine the efficacy of mild® compared with placebo or to determine the efficacy of image-guided minimally invasive lumbar decompression compared with open decompression. Trials with relevant control groups could provide greater certainty on the risks and benefits of this procedure. The evidence is insufficient to determine the effects of the technology on health outcomes.
SUPPLEMENTAL INFORMATION
Practice Guidelines and Position Statements
North American Spine Society
In 2011, the North American Spine Society revised clinical practice guidelines on the diagnosis and treatment of degenerative lumbar spinal stenosis.13, Treatment recommendations included:
- Interlaminar epidural steroid injection for short-term (two weeks to six months) symptom relief in patients with neurogenic claudication or radiculopathy; however, there is conflicting evidence regarding long-term efficacy. (Grade of Recommendation: B)
- A multiple injection regimen of radiographically-guided transforaminal epidural steroid injection or caudal injection for medium-term relief of pain. (Grade of Recommendation: C)
- Decompressive surgery to improve outcomes in patients with moderate to severe symptoms of lumbar spinal stenosis. (Grade of Recommendation: B)
No specific recommendations on percutaneous image-guided lumbar decompression were provided.
Lumbar Spinal Stenosis Consensus Group MIST Guidelines
In 2018, the Lumbar Spinal Stenosis Consensus Group, composed of a panel of nationally recognized spine experts, convened to evaluate the available literature and develop guidelines for minimally invasive spine treatment.14, Based on a systematic review of the available literature on percutaneous image-guided lumbar decompression, the consensus committee determined there is sufficient support to warrant Level I evidence (Grade A, Level I, Consensus strong). Grade A evidence is defined as "extremely recommendable (good evidence that the measure is effective and that benefits outweigh the harms."
U.S. Preventive Services Task Force Recommendations
Not applicable.
Ongoing and Unpublished Clinical Trials
Some currently unpublished trials that might influence this policy are listed in Table 4.
Table 4. Summary of Key Trials
NCT No. | Trial Name | Planned Enrollment | Completion Date |
Ongoing |  |  |  |
NCT03072927a | MILD® Percutaneous Image-Guided Lumbar Decompression: A Medicare Claims Study | 4000 | Dec 2020
(recruiting) |
NCT03610737a | A Multi-center, Randomized Controlled Study of the VertosMILD Procedure With Conventional Medical Management Versus Conventional Medical Management Alone in the Treatment of Lumbar Spinal Stenosis (MOTION) | 150 | Feb 2022
(ongoing) |
Unpublished |  |  |  |
NCT01129921a | Comparative Study of Sham Versus Mild® (Minimally Invasive Lumbar Decompression) Procedure in Patients Diagnosed With Symptomatic Moderate to Severe Lumbar Central Canal Stenosis | 40 | Oct 2011
(completed) |
NCT: national clinical trial.
a Denotes industry-sponsored or cosponsored trial.]
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Horizon BCBSNJ Medical Policy Development Process:
This Horizon BCBSNJ Medical Policy (the “Medical Policy”) has been developed by Horizon BCBSNJ’s Medical Policy Committee (the “Committee”) consistent with generally accepted standards of medical practice, and reflects Horizon BCBSNJ’s view of the subject health care services, supplies or procedures, and in what circumstances they are deemed to be medically necessary or experimental/ investigational in nature. This Medical Policy also considers whether and to what degree the subject health care services, supplies or procedures are clinically appropriate, in terms of type, frequency, extent, site and duration and if they are considered effective for the illnesses, injuries or diseases discussed. Where relevant, this Medical Policy considers whether the subject health care services, supplies or procedures are being requested primarily for the convenience of the covered person or the health care provider. It may also consider whether the services, supplies or procedures are more costly than an alternative service or sequence of services, supplies or procedures that are at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of the relevant illness, injury or disease. In reaching its conclusion regarding what it considers to be the generally accepted standards of medical practice, the Committee reviews and considers the following: all credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, physician and health care provider specialty society recommendations, the views of physicians and health care providers practicing in relevant clinical areas (including, but not limited to, the prevailing opinion within the appropriate specialty) and any other relevant factor as determined by applicable State and Federal laws and regulations.
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Index:
Image-Guided Minimally Invasive Decompression for Spinal Stenosis
Image-Guided Minimally Invasive Lumbar Decompression (IG-MLD) for Spinal Stenosis
Minimally Invasive Lumbar Decompression for Spinal Stenosis
MILD for Spinal Stenosis
X-Sten MILD Tool Kit
References:
1. Chou R, Baisden J, Carragee EJ, et al. Surgery for low back pain: a review of the evidence for an American Pain Society Clinical Practice Guideline. Spine. May 1 2009;34(10):1094-1109. PMID 19363455
2. Chou R, Loeser JD, Owens DK, et al. Interventional therapies, surgery, and interdisciplinary rehabilitation for low back pain: an evidence-based clinical practice guideline from the American Pain Society. Spine. May 1 2009;34(10):1066-1077. PMID 19363457
3. Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis. N Engl J Med. May 31 2007;356(22):2257-2270. PMID 17538085
4. Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med. Feb 21 2008;358(8):794-810. PMID 18287602
5. Staats PS, Benyamin RM. MiDAS ENCORE: randomized controlled clinical trial report of 6-month results. Pain Physician. Feb 2016;19(2):25-38. PMID 26815247
6. Benyamin RM, Staats PS, Mi DASEI. MILD(R) is an effective treatment for lumbar spinal stenosis with neurogenic claudication: MiDAS ENCORE randomized controlled trial. Pain Physician. May 2016;19(4):229-242. PMID 27228511
7. Staats PS, Chafin TB, Golovac S et al. Long-Term Safety and Efficacy of Minimally Invasive Lumbar Decompression Procedure for the Treatment of Lumbar Spinal Stenosis With Neurogenic Claudication: 2-Year Results of MiDAS ENCORE. Reg Anesth Pain Med. 2018 Oct;43(7). PMID 30199512
8. Kreiner DS, Macvicar J, Duszynski B, et al. The mild(R) Procedure: a systematic review of the current literature. Pain Med. Feb 2014;15(2):196-205. PMID 24308292
9. Brown LL. A double-blind, randomized, prospective study of epidural steroid injection vs. the mild(R) procedure in patients with symptomatic lumbar spinal stenosis. Pain Pract. Jun 2012;12(5):333-341. PMID 22272730
10. Chopko BW. Long-term results of percutaneous lumbar decompression for LSS: two-year outcomes. Clin J Pain. Nov 2013;29(11):939-943. PMID 23446067
11. Chopko BW. A novel method for treatment of lumbar spinal stenosis in high-risk surgical candidates: pilot study experience with percutaneous remodeling of ligamentum flavum and lamina. J Neurosurg Spine. Jan 2011;14(1):46-50. PMID 21142460
12. Lingreen R, Grider JS. Retrospective review of patient self-reported improvement and post-procedure findings for mild (minimally invasive lumbar decompression). Pain Physician. Nov-Dec 2010;13(6):555-560. PMID 21102968
13. North American Spine Society (NASS). Evidence-Based Clinical Guidelines for Multidisciplinary Spine Care: Diagnosis and Treatment of Degenerative Lumbar Spinal Stenosis. 2011; https://www.spine.org/Portals/0/Assets/Downloads/ResearchClinicalCare/Guidelines/LumbarStenosis.pdf. Accessed March 10, 2020.
14. Deer TR, Grider JS, Pope JE et al. The MIST Guidelines: The Lumbar Spinal Stenosis Consensus Group Guidelines for Minimally Invasive Spine Treatment. Pain Pract. 2019 Mar;19(3). PMID 30369003
15. Centers for Medicare & Medicaid Services. National Coverage Determination (NCD) for Percutaneous Image-guided Lumbar Decompression for Lumbar Spinal Stenosis (150.13). 2016; https://www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?NCDId=358. Accessed March 10, 2020.
Codes:
(The list of codes is not intended to be all-inclusive and is included below for informational purposes only. Inclusion or exclusion of a procedure, diagnosis, drug or device code(s) does not constitute or imply authorization, certification, approval, offer of coverage or guarantee of payment.)
CPT*
HCPCS
* CPT only copyright 2020 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.
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Medical policies can be highly technical and are designed for use by the Horizon BCBSNJ professional staff in making coverage determinations. Members referring to this policy should discuss it with their treating physician, and should refer to their specific benefit plan for the terms, conditions, limitations and exclusions of their coverage.
The Horizon BCBSNJ Medical Policy Manual is proprietary. It is to be used only as authorized by Horizon BCBSNJ and its affiliates. The contents of this Medical Policy are not to be copied, reproduced or circulated to other parties without the express written consent of Horizon BCBSNJ. The contents of this Medical Policy may be updated or changed without notice, unless otherwise required by law and/or regulation. However, benefit determinations are made in the context of medical policies existing at the time of the decision and are not subject to later revision as the result of a change in medical policy
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