Surgery Section - Percutaneous Discectomy

IMPORTANT REMINDER

This Medical Policy has been developed through consideration of medical necessity, generally accepted standards of medical practice, and review of medical literature and government approval status.

Benefit determinations should be based in all cases on the applicable contract language. To the extent there are any conflicts between these guidelines and the contract language, the contract language will control.

The purpose of medical policy is to provide a guide to coverage. Medical Policy is not intended to dictate to providers how to practice medicine. Providers are expected to exercise their medical judgment in providing the most appropriate care.

Description

Back pain related to herniated discs is an extremely common condition and a frequent cause of chronic disability. Although many cases of acute low back pain will resolve with conservative care, a surgical decompression is often considered when the pain is unimproved after a month and is clearly neuropathic in origin, resulting from irritation of the nerve roots. Open surgical treatment typically consists of some sort of discectomy, where the extruding disc material is excised. Minimally invasive options have also been researched, in which some portion of the disc material is removed or ablated, although these techniques are not precisely targeted at the offending extruding disc material. Ablative techniques include laser discectomy and radiofrequency decompression (see Surgery policy No. 131). In addition, intradiscal electrothermal annuloplasty is another minimally invasive approach to low back pain. In this technique, radiofrequency energy is used to treat the surrounding disc annulus (see Surgery policy No. 118).

This policy addresses percutaneous lumbar discectomy (PLD), in which the disc decompression is accomplished by the physical removal of disc material rather than its ablation. Originally, PLD was performed manually, using cutting forceps to remove nuclear material from within the disc annulus. This technique has been replaced with automated devices that involve placement of a probe within the intervertebral disc and aspiration of disc material using a suction cutting device. The Stryker DeKompressor Percutaneous Discectomy Probe (Stryker), Laurimed Percutaneous Discectomy System, Richard Wolf Percutaneous Endoscopic Discectomy Instruments, percutaneous discectomy Cannula System (T. Koros) and the Nucleotome (Clarus Medical) are examples of percutaneous discectomy devices that received clearance from the U.S. Food and Drug Administration (FDA) through the 510(k) process. Both have the same labeled intended use, i.e., “for use in aspiration of disc material during percutaneous discectomies in the lumbar, thoracic and cervical regions of the spine.”

Policy/Criteria

Percutaneous discectomy is considered investigational as a technique of intervertebral disc decompression in patients with back pain related to disc herniation in the lumbar, thoracic, or cervical spine.

Scientific Background

This policy was originally based on a 1990 TEC Assessment, which concluded that percutaneous discectomy met the TEC criteria. Therefore, the original policy concluded that percutaneous discectomy was considered medically necessary in carefully selected patients. This policy statement remained unchanged until 2005. Since the 1990 TEC Assessment, the methodology of evidence-based medicine in general has grown in sophistication. Specifically, it is recognized that randomized clinical trials are extremely important to assess treatments of painful conditions and low back pain in particular, due both to the expected placebo effect, the subjective nature of pain assessment in general, and also the variable natural history of low back pain that often responds to conservative care. Disc decompression using lasers or radiofrequency energy to ablate disc material is a relatively new minimally invasive technique that is considered an alternative to percutaneous discectomy. Both of these techniques, addressed in Surgery policy No. 131, are considered investigational, in part due to the lack of controlled trials. Therefore, this policy on percutaneous discectomy is reviewed again in 2005, applying the same evidence standard as that used for laser or radiofrequency decompression procedures.

The literature was searched for the period of 1990 to September 2005 with a specific focus on controlled clinical trials comparing percutaneous discectomy to either open discectomy or conservative therapy. The literature search identified a large number of case series, but only 5 controlled trials, 4 of which were reviewed in a 2000 Cochrane report. (2) (All of these controlled trials were published after 1990 and thus were not reviewed as part of the TEC Assessment.) The Cochrane review concluded, “Three trials of percutaneous discectomy provided moderate evidence that it produces poorer clinical outcomes than standard discectomy or chymopapain.” For example, Chatterjee reported on the results of a study that randomized 71 patients with lumbar disc herniation to undergo either percutaneous discectomy or lumbar microdiscectomy. (3) A successful outcome was reported in only 29% of those undergoing percutaneous discectomy compared to 80% in the microdiscectomy group. The trial was halted early due to this inferior outcome. In a 1993 randomized study, Revel and colleagues compared the outcomes of percutaneous discectomy to chymopapain injection in 141 patients with disk herniation and sciatica. (4) Treatment was considered successful in 61% of patients in the chymopapain group compared to 44% in the percutaneous discectomy group. Another trial cited in the Cochrane review, Mayer et al, is not applicable since the technique used modified forceps in addition to a suction probe. (5) Finally, the last trial cited in the Cochrane review, Hermantin et al, provided insufficient data to allow detailed analysis of results. (6)

The only additional controlled study published since the 2000 Cochrane review is the LAPDOG study, a randomized trial designed to compare percutaneous and open discectomy in patients with lumbar disc herniation. (7) This trial was designed to recruit 330 patients, but only was able to recruit 36 patients, for reasons that were not readily apparent to the authors. Of the evaluable 27 patients, 41% of the percutaneous discectomy patients and 40% of the conventional discectomy patients were assessed as having successful outcomes at 6 months. The authors concluded that this trial was unable to enroll sufficient numbers of patients to reach a definitive conclusion. The authors state, “It is difficult to understand the remarkable persistence of percutaneous discectomy in the face of a virtually complete lack of scientific support for its effectiveness in treated lumbar disc herniation.”

All of the trials reviewed above focused on lumbar disc herniation. There were no clinical trials of percutaneous discectomy of cervical or thoracic disc herniation.

Summary

Using a standard of controlled clinical trials to evaluate the safety and effectiveness of percutaneous discectomy, there are inadequate published data to permit scientific conclusions.

An updated search of the literature through September 2006 returned several small case series with short term follow-up, none of which would prompt reconsideration of the policy criteria. (8-11) In May 2005 the American Academy of Orthopedic Surgeons issued an Advisory Statement concerning use of thermal modalities (laser and radiofrequency devices) in orthopedic (including lumbar spine) surgeries. (12) Based on their review of the scientific evidence and expert opinion the AAOS made the following statement:

“Clinical studies reported in orthopedic literature have not established the significant benefit provided by thermal modalities when compared to other systems now in use.  As further clinical research in thermal applications becomes available, the American Academy of Orthopedic Surgeons (AAOS) encourages investigators to pay special attention to those areas where the techniques can be shown to be effective additions to orthopedic care.”

An updated search of the MEDLINE database through August 2007 did not identify any additional controlled trials. Gibson and Waddel published an updated Cochrane review of surgical interventions for lumbar disc prolapse, concluding that there is insufficient evidence on percutaneous discectomy techniques to draw firm conclusions.(13)  A task force of the American Society of Interventional Pain Physicians reported that percutaneous disc decompression remains controversial; although all observational studies were positive, the evidence from 4 of 4 randomized published studies was negative.(14) Questions also remain about the appropriate patient selection criteria (particularly related to the size and migration of the disc herniation) for this procedure. (13, 14)

2008 Update

An updated search of the MEDLINE database in October 2008 failed to return any new relevant studies.  Freeman and Mehdian assessed the current evidence for three minimally invasive techniques used to treat discogenic low back pain and radicular pain: electrothermal therapy (IDET), percutaneous discectomy, and nucleoplasty. (15) They report that trials of automated percutaneous discectomy suggest that clinical outcomes are at best fair and often worse when compared with microdisctomy.

References

1. BlueCross and BlueShield Association Medical Policy Reference Manual, Policy No. 7.01.18
2. Gibson JNA, Grant IC, Waddell G. Surgery for lumbar disc prolapse. (Cochrane Review). In: the Cochrane Library, Issue 2, 2003. Oxford: Update Software
3. Chatterjee S, Foy PM, Findlay GF. Report of a controlled clinical trial comparing automated percutaneous lumbar discectomy and microdiscectomy in the treatment of contained lumbar disc herniation. Spine 1995;20(6):734-8
4. Revel M, Payan C, Vallee C et al. Automated percutaneous lumbar discectomy versus chemonucleolysis in the treatment of sciatica. Spine 1993;18(1):1-7
5. Mayer HM, Brock M. Percutaneous endoscopic discectomy: surgical technique and preliminary results compared to microsurgical discectomy. J Neurosurg 1993;78(2):216-25
6. Hermantin FU, Peters T, Quartararo L et al. A prospective, randomized study comparing the results of open discectomy with those of video-assisted arthroscopic discectomy. J Bone Joint Surg Am 1999;81(7):958-65
7. Haines SJ, Jordan N, Boen JR et al. Discectomy strategies for lumbar disc herniation: results of the LAPDOG trial.  J Clin Neurosci 2002;9(4):411-7
8. Amoretti N, David P, Grimaud A  et al. Clinical follow-up of 50 patients treated by percutaneous lumbar discectomy. Clin Imaging. 2006 Jul-Aug;30(4):242-4
9. Kafadar A, Kahraman S, Akboru M. et al. Percutaneous endoscopic transforaminal lumbar discectomy: a critical appraisal. Minim Invasive Neurosurg. 2006 Apr;49(2):74-79
10. Lee SH, Uk Kang B, Ahn Y et al.  Operative failure of percutaneous endoscopic lumbar discectomy: a radiologic analysis of 55 cases. Spine. 2006 May 1;31(10):E285-90
11. Pomerantz SR, Hirsch JA. Intradiscal therapies for discogenic pain. Semin Musculoskelet Radiol. 2006 Jun;10(2):125-35
12. American Academy of Orthopedic Surgeons Advisory Statement:  Use of Thermal Modalities (Lasers and Radiofrequency Devices) in Orthopaedic Surgery(Verified  12/10/08)
13. Gibson JN, Waddell G. Surgical interventions for lumbar disc prolapse. Cochrane Database Syst Rev 2007;(2):CD001350
14. Boswell MV, Trescot AM, Datta S et al; American Society of Interventional Pain Physicians. Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. Pain Physician 2007;10(1):7-111
15. Freeman BJ and Mehdian R. Intradiscal electrothermal therapy, percutaneous discectomy, and nucleoplasty: what is the current evidence? Curr Pain Headache Rep 2008;12(1):14-21

Cross References

Decompression of Intervertebral Disc Using Laser (Laser Discectomy) or Radiofrequency Energy (Disc Nucleoplasty), Regence Medical Policy Manual, Surgery, Policy No. 131

Percutaneous Intradiscal Electrothermal Annuloplasty (IDET) and Percutaneous Intradiscal Radiofrequency Thermocoagulation, Regence Medical Policy Manual, Surgery, Policy No. 118

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