Tuesday, January 09, 2007

Surgery Section - Lysis of Epidural Adhesions

Topic: Lysis of Epidural Adhesions
Date of Origin: 02/1999
Section: Surgery
Policy No: 94
Approved Date: 10/03/2006
Effective Date: 10/03/2006
Next Review Date: 10/2007
IMPORTANT REMINDERThis 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.
Epidural fibrosis with or without adhesive arachnoiditis most commonly occurs as a complication of spinal surgery and may be included under the diagnosis of "failed back syndrome." Both result from manipulation of the supporting structures of the spine. Epidural fibrosis can occur in isolation, but adhesive arachnoiditis is rarely present without associated epidural fibrosis. Arachnoiditis is most frequently seen in patients who have undergone multiple surgical procedures.Both conditions are related to inflammatory reactions that result in the entrapment of nerves within dense scar tissue, increasing the susceptibility of the nerve root to compression or tension. The condition most frequently involves the nerves within the lumbar spine and cauda equina. Signs and symptoms indicate the involvement of multiple nerve roots, and include low back pain, radicular pain, tenderness, sphincter disturbances, limited trunk mobility, muscular spasm or contracture, motor sensory and reflex changes. Typically, the pain is characterized as constant and burning. In some cases the pain and disability are severe, leading to analgesic dependence and chronic invalidism.Lysis of epidural adhesions, using fluoroscopic guidance, with epidural injections of hypertonic saline in conjunction with steroids and analgesics has been investigated as a treatment option. Theoretically, the use of hypertonic saline results in a mechanical disruption of the adhesions. It may also function to reduce edema within previously scarred and/or inflamed nerves. Finally, adhesions may be disrupted by manipulating the catheter at the time of the injection. Spinal endoscopy has been used to guide the lysis procedure. Prior to use of endoscopy, adhesions can be identified as non-filling lesions on fluoroscopy. Using endoscopy guidance, a flexible fiberoptic catheter is inserted into the sacral hiatus, providing 3-D visualization to steer the catheter toward the adhesions, to more precisely place the injectate in the epidural space and onto the nerve root. Various protocols for lysis have been described; in some situations the catheter may remain in place for several days for serial treatment sessions.
Catheter-based techniques for lysis of epidural adhesions, with or without endoscopic guidance, are considered investigational. Techniques used either alone or in combination include mechanical disruption with a catheter and/or injection of hypertonic solutions with steroids, analgesics or hyaluronidase.Scientific Background
In general, the published scientific literature concerning lysis of epidural adhesions consists of small single institution studies, most of which suffer from significant methodologic issues that limit scientific interpretation of the data. The protocol describing the procedure was originally published in a monograph. (2) According to this protocol, an indwelling epidural catheter is placed for three days. The patients then receive injections of local anesthetics, steroids, and hypertonic saline once daily. During the ensuing pain-free period, the patient undergoes extensive physical therapy. Since lysis of the fibrosis is often incomplete after one treatment session, the procedure is frequently repeated at three months. This protocol described the technique itself but did not present a formal discussion of the patient outcomes associated with the procedure.
In the monograph, Racz and Holubec summarized the responses of 72 patients who underwent the protocol described above. (2) These patients were randomly selected from the total case series of 200 patients. Most of the patients had previously undergone multiple spinal surgeries. A total of 47 patients (65%) reported either good or excellent pain relief. The duration of pain relief varied: in 37% it lasted less than one month; in 30% it lasted between 1 and 3 months; and in 12% pain relief lasted between 3 and 6 months.
In 2004, Manchikanti and colleagues published the results of a trial that randomized 75 patients to one of three groups (3):
catheterization without adhesiolysis;
adhesiolysis with additional hypertonic saline; or
adhesiolysis without additional hypertonic saline.
All patients received epidural injections of local anesthetic and steroids. Patient selection criteria included a history of chronic low back pain of at least two years that had failed conservative treatment, including epidural steroid injections. Outcomes were assessed at 3, 6 and 12 months based on VAS pain scale, Oswestry Disability Index, work status, opioid intake, range of motion, and psychological exam. Unblinding was allowed at three months based on treatment response, followed by crossover to another treatment group. It is not clear from the published article how this assessment was made. In the control group of 25 patients, 6 patients were unblinded at 3 months, 12 at 6 months, and 6 at 12 months. Once patients were unblinded, they were considered withdrawn, and no subsequent data was collected. The results of their last assessment were carried forward to the next assessment. For example, if a patient was unblinded at 3 months, the same outcomes were reported at 6 and 12 months. Therefore, this discussion focuses on the 3-month outcomes.
Significant differences in pain relief, Oswestry Disability Index and range of motion were noted between the two treatment groups and the control group. For example, the mean VAS score was not significantly improved in the control group, dropping from 8.9 to 7.7, while in the treatment groups the VAS dropped from 8.8 to 4.6. A total of 40% of the control group had no response with the first treatment, compared to only 16% in the adhesiolysis group. At three months, no patient in the control group reported significant relief, defined as at least 50% relief, while at least 64% of patients in the treatment group reported significant relief. While this study is adequately designed and does report positive results, its small size and the fact that it is a single institution study limit interpretation. The dramatic effect reported in this study needs to be confirmed in a larger multi-institutional study.Other reported trials have significant methodologic issues that limit scientific interpretation. One controlled trial included 45 patients who were randomized to receive either a 1- or 3-day course of lysis of epidural adhesions, although details of the randomization and treatment protocols are not provided, and it is not clear what, if any, randomization took place. (4) The trial also included a conservatively treated control group of 15 patients who either refused the treatment option, or whose insurance refused to pay. Although the study did not provide details on how pain relief was evaluated, describing only a verbal 10-point scale, the study concluded that a total of 97% of the treatment group reported at least 50% pain relief with 1 to 3 injections at 3 months, which fell to 93% at 6 months, and 47% at 1 year. There was no significant improvement in the control group. However, the lack of a placebo control and the obvious bias of the control group limit the interpretation of these findings. One other identified article compared the use of 0.9% saline solution versus 10% saline solution but did not control other aspects of the pain management program. (5)
Epidural lysis of adhesions is discussed in chapters of textbooks and in numerous review articles; however, the absence of controlled trials makes scientific conclusions impossible regarding its efficacy. (6-9) A 2005 review article focused on three randomized trials by Heavner and Manchikanti and concluded that there was moderate to strong evidence of the effectiveness of percutaneous adhesiolysis. (10) Boswell and colleagues (11) reached similar conclusions; however, neither publication included a systematic analysis of the quality of the data. In addition, Boswell and colleagues included data from nonrandomized studies in their review. The randomized studies referenced in these publications have been previously reviewed separately in this policy, with the conclusion that methodological issues limit interpretation of the results.
In 2003, a new Category III CPT code was introduced to describe lysis of epidural adhesions using endoscopic guidance. One randomized controlled trial was identified. Manchikanti and colleagues randomized 23 patients with back pain of greater than 6 months’ duration to receive either spinal endoscopy followed by injection of local anesthetic or steroid (control group) or the above procedure with the addition of lysis of adhesions with normal saline and mechanical disruption with the fiberoptic endoscope. (12) The trial was double blinded. Patient selection criteria included failure of conservative management, including failure of prior attempts at lysis of adhesions using hypertonic saline. The principal outcomes included changes in the VAS scores and Oswestry Disability scale at 6 months. In the control group the mean VAS score dropped from 8.7 at baseline to 7.6 at 6 months, while the scores in the intervention group dropped from 9.2 at baseline to 5.7 at 6 months. The difference between the control and intervention group was statistically significant. There was also a significant difference between the two groups in the percentage of patients experiencing at least a 50% reduction in pain. Blinding appeared to be successful as 6 of the 16 patients in the control group believed that they were in the intervention group, and 8 of 23 patients in the intervention group believed that they were in the control group. While this study reports promising results, its small size limits interpretation.
Two articles were identified that retrospectively examined the outcomes of patients who underwent lysis with (n=120) or without (n=60) adjunctive endoscopy. (13,14) As these articles are authored by the same investigator, it is likely that they include overlapping patients. However, these studies did not include a control group, and thus scientific conclusions regarding the contribution of endoscopy are not possible. Finally, Geurts and colleagues report on a case series of 20 patients who underwent spinal endoscopy with lysis of adhesions using hyaluronidase in addition to injection of methylprednisolone acetate and clonidine. (15) The independent contribution of the lysis cannot be assessed. Furthermore, this study did not include a control group. Manchikanti and colleagues recently reported results of a randomized trial of endoscopic adhesiolysis compared to caudal epidural steroid injection. (16) Again, the independent contribution of the adhesiolysis cannot be assessed as targeted injections of both local anesthetic and steroids were given to the intervention group. In addition, a true comparison between treatment and control groups cannot be made as the control group received local anesthetic and steroid injections at S3, whereas the intervention group received targeted injections following adhesiolysis at the level of suspected pathology (L4, L5, S1). Other methodologic issues limiting scientific interpretation of the study outcomes include the introduction of bias as a result of 2:3 randomization (patients entered the study believing they had a higher chance of being included in the treatment group) and the unblinding of some patients at three months, although an intent-to-treat analysis was performed.
In summary, the available evidence is not sufficient to draw conclusions concerning the health outcome effects of lysis of epidural adhesions. Most of the published literature to date suffers from significant methodologic issues that limit scientific interpretation of the data. Promising results reported in one small randomized trial have yet to be duplicated in other trials. An updated search of the MEDLINE database through September 2006 failed to identify any additional published data that alter this conclusion. While controlled studies are now being conducted, they continue to be small, single institution studies. (16, 17) Larger, multi-institution studies are needed to adequately evaluate this procedure.

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