Surgery Section - Percutaneous Intradiscal Electrothermal Annuloplasty (IDET) and Percutaneous Intradiscal Radiofrequency Thermocoagulation

IMPORTANT REMINDER

Regence Medical Policies are developed to provide guidance for members and providers regarding coverage in accordance with contract terms. Benefit determinations are based in all cases on the applicable contract language. To the extent there may be any conflict between the Medical Policy and contract language, the contract language takes precedence.

PLEASE NOTE: Contracts exclude from coverage, among other things, services or procedures that are considered investigational or cosmetic. Providers may bill members for services or procedures that are considered investigational or cosmetic. Providers are encouraged to inform members before rendering such services that the members are likely to be financially responsible for the cost of these services.

DESCRIPTION ^[1]

Intradiscal annuloplasty therapies use radiofrequency energy to thermally treat discogenic low back pain arising from annular tears and other forms of internal disc derangement. In contrast with disc nucleoplasty, which ablates disc material, thermal annuloplasty techniques are designed to decrease pain arising from the annulus and enhance its structural integrity. It has been proposed that heat-induced denaturation of collagen fibers in the annular lamellae may stabilize the disc and potentially seal annular fissures, and that pain reduction may occur through the thermal coagulation of nocioceptors in the outer annulus.

With the intradiscal electrothermal annuloplasty procedure (IDET™, Oratec SpineCath System), a navigable catheter with an embedded thermal resistive coil is inserted posterolaterally into the disc annulus or nucleus. The catheter is then snaked through the disc circuitously to return posteriorly. Using indirect radiofrequency energy, electrothermal heat is generated within the thermal resistive coil at a temperature of 90 degrees centigrade; the disc material is heated for up to 20 minutes. Proposed advantages of indirect electrothermal delivery of radiofrequency energy with IDET include precise temperature feedback and control, and the ability to provide electrothermocoagulation to a broader tissue segment than would be allowed with a direct radiofrequency needle.

Another procedure, referred to as percutaneous intradiscal radiofrequency thermocoagulation (PIRFT), uses direct application of radiofrequency energy. With PIRFT, the radiofrequency probe is placed into the center of the disc and the device is activated for only 90 seconds at a temperature of 70 degrees centigrade. The procedure is not designed to coagulate, burn, or ablate tissue. The Radionics RF Disc Catheter System has been specifically designed for this purpose.

A more recently developed annuloplasty procedure, referred to as intradiscal biacuplasty (Baylis Medical, Inc., Montreal, Canada), involves the use of two cooled radiofrequency electrodes placed on the posterolateral sides of the intervertebral annulus fibrosus. It is believed that by cooling the probes a larger area may be treated than could occur with a regular needle probe.

Regulatory Status

IDET™, Oratec Nucleotomy Catheter received marketing clearance through the U.S. Food and Drug Administration’s (FDA) 510(k) process in 2002. The predicate device was the SpineCATH Intradiscal Catheter, which received FDA clearance for marketing in 1999. Radionics (Burlington, MA - a division of Tyco Healthcare group) RF Disc Catheter System received marketing clearance through the FDA’s 510(k) process in 2000. Valleylab (Boulder, CO - another division of Tyco Healthcare) is marketing the DiscTRODE™ RF catheter electrode system for use with the RFG-3CPlus™ RF lesion generator in the U.S.

The Baylis Pain Management Cooled Probe received marketing clearance through the U.S. Food and Drug Administration’s 510(k) process in 2005. It is intended for use “in conjunction with the Radio Frequency Generator to create radiofrequency lesions in nervous tissue.”

POLICY/CRITERIA

Percutaneous annuloplasty (e.g., intradiscal electrothermal annuloplasty, percutaneous intradiscal radiofrequency thermocoagulation, or intradiscal biacuplasty) for the treatment of chronic discogenic back pain is considered investigational.

SCIENTIFIC BACKGROUND

Intradiscal Electrothermal Annuloplasty (IDET)

This policy is based in part on a 2002 TEC Assessment, ^[2] which was updated in 2003 ^[3], and subsequent literature reviews. Data published prior to the 2003 Assessment consisted primarily of case series of patients. As with any therapy for pain, a placebo effect is anticipated, and thus randomized placebo-controlled trials are necessary to investigate the extent of the placebo effect and to determine whether any improvement with annuloplasty exceeds that associated with a placebo. Therefore, evidence reviewed for this policy focuses on randomized controlled trials.

Systematic reviews

A systematic review of IDET and PIRFT was conducted following the criteria recommended by the Cochrane Back Review Group. ^[4] Four randomized and 2 nonrandomized studies, totaling 283 patients, were included in the review. The report concluded that the available evidence does not support the efficacy or effectiveness of IDET or PIRFT, and that these procedures are associated with potentially serious side effects. An industry funded meta-analysis and systematic review were recently published that support the use of IDET. ^[5,6] However, the quality of the studies included in these reviews was poor; 14 of the 18 studies reviewed did not have appropriate controls.

In addition to the systematic reviews described above, a number of other reviews from 2008 and 2009 have varying conclusions about the evidence for IDET annuloplasty ^[7-9]; these reviews found no evidence to support a role for radiofrequency annuloplasty. Evidence is insufficient to conclude that these procedures improve health outcomes.

Randomized controlled trials

In 2003, Pauza and colleagues published the results of a randomized study ^[10], which was the focus of discussion in the 2003 TEC Assessment. The study included 64 patients with low back pain of greater than 6 months’ duration who were randomized to receive either IDET or a sham procedure.  Visual analogue scale (VAS) pain was reduced by an average of 2.4 cm in the IDET group, compared with 1.1 cm in the sham group, a significant difference between groups (p=0.045). The mean change in the Oswestry disability scale was also significantly greater for the IDET group compared with the sham group. The improvement on the SF-36 Bodily Pain subscale was nearly significantly higher for the IDET group. The authors stated that per-protocol analyses were conducted, which excluded data from 8 patients, 5 from the IDET group, and 3 from the sham group. One patient died, 1 was lost to follow-up, 1 had unsatisfactory electrode placement, 1 had post-treatment bone fracture, and 2 had new injuries unrelated to low back pain and were excluded due to compensation claims or opioids. While the per-protocol analyses are consistent with the study question assessing the efficacy of IDET compared with sham treatment, intent-to-treat analysis, which includes all patients randomized, is the preferred method because it is less likely to introduce bias. The Pauza study did not appear to use this method of analysis.

Besides failing to perform intent-to-treat analyses, there are additional concerns about statistical methods used by Pauza et al. Potential confounding should be assessed and necessary adjustments should be made. The report noted that the analysis of SF-36 Role Physical scores adjusted for differences at baseline, but whether the comparison used adjustment and statistical techniques was not specified. The technique for comparing group scores on continuous variables was described only as a t-test, suggesting simple comparison of mean change at follow-up. More appropriate techniques for comparing changes between groups include analysis of covariance and repeated measure analysis of variance. It is also important to report an appropriate measure of effect with an index of the precision of estimation (i.e., the confidence interval). The comparison of means on the VAS for pain and the ODS for disability do not readily reveal how often patients achieve a clinically significant improvement. Minimally significant improvement in VAS has been estimated at 1.8–1.9 cm, and by this estimate, the mean change in VAS of 2.4 cm for IDET would be considered clinically significant. However, a small number of extreme values can influence this measure. The study also reported the percentage with a change in VAS of more than 2.0 cm, which is greater than the minimally clinically significant improvement of 1.8–1.9. When the VAS is dichotomized in this way, a relative risk of 1.5 is observed with a 95% confidence interval of 0.82–2.74. Although these data suggest a higher relative probability of achieving a minimally clinically significant improvement for the IDET group, this estimation lacks precision and is not clinically significant.

It is interesting to note that, although the sham procedure consisted only of insertion of a needle into the patient's back, 38% of patients in the sham group reported improvement in pain of greater than 20 points, 33% reported greater than 50% improvement, and one patient reported complete relief of pain. These results illustrate the importance of placebo-controlled trials of pain therapies. In uncontrolled trials of pain therapies, what appear to be reasonable or promising outcomes may be the result of no more than "having a procedure."

In summary, the Pauza trial is a well-designed trial with respect to randomization, clear description of intervention, and use of valid and reliable outcomes measures. However, this single center trial does not permit conclusions about the relative effects of IDET and placebo. The study did not conduct intent to treat analysis, and it is unclear whether IDET achieves clinically and statistically significant improvements in measures of pain, disability, and quality of life.

A double-blinded randomized controlled trial (RCT) with 57 patients (38 IDET, 19 placebo) found IDET to be no more effective than sham stimulation, and no subject in either group achieved a successful outcome. ^[11] In another study, comparison of 21 electrothermal (IDET) and 21 radiofrequency procedures found significant improvements in a majority of IDET patients but not in matched radiofrequency-treated patients at 1-year follow-up; the study did not have a placebo-control group. ^[12]

Percutaneous Intradiscal Radiofrequency Thermocoagulation (PIRFT)

There is relatively minimal published data on PIRFT. In 2001, Barendse and colleagues reported on a double-blind trial that randomized 28 patients with chronic low back pain to undergo PIRFT or a sham control group. ^[13] The primary outcome was the percentage of success at 8 weeks, as measured by changes in pain level, impairment, Oswestry disability scale, and analgesics taken. At the end of 8 weeks, there were 2 treatment successes in the sham group compared to 1 in the treatment group. The authors concluded that PIRFT was not better than the placebo procedure in reducing pain and disability.

In 2009, Kvarstein and colleagues published 12-month follow-up from a RCT of intra-annular radiofrequency thermal disc therapy using the discTRODE™ probe from Radionics. ^[14] Recruitment was discontinued when blinded interim analysis of the first 20 patients showed no trend toward overall effect or difference in pain intensity between active and sham treatment at 6 months. At 12 months, there was a reduction from baseline pain, but no significant difference between the 2 groups. Two patients from each group reported an increase in pain. Although this controlled study did not find evidence for a benefit of PIRFT, it may not have been powered to detect a small or moderate effect of the procedure.

Biacuplasty

One case report of transdiscal radiofrequency annuloplasty using 2 transdiscal probes (biacuplasty) was identified in 2007; the authors indicate this to be the first publication with this procedure. ^[15]

Technology Assessments, Guidelines, and Position Statements

Evidence-based guidelines from the American Society of Interventional Pain Physicians concluded that the evidence is moderate for management of chronic discogenic low back pain with IDET. ^[16] Complications included catheter breakage, nerve root injuries, post-IDET disc herniation, cauda equine syndrome, infection, epidural abscess, and spinal cord damage. The evidence for radiofrequency posterior annuloplasty, the evidence was limited for short-term improvement, and indeterminate for long-term improvement in managing chronic discogenic low back pain. The evidence for radiofrequency posterior annuloplasty (PIRFT) was reported to be limited for short-term improvement, and indeterminate for long-term improvement in managing chronic discogenic low back pain. Complications were similar to IDET.

The National Institute for Health and Clinical Excellence (NICE) guidance published in 2004 indicates that the current evidence on safety and efficacy of percutaneous intradiscal radiofrequency thermocoagulation for lower back pain does not appear adequate to support its use. ^[17] A separate NICE guidance, updated in 2009, indicates that the current evidence on safety and efficacy of percutaneous intradiscal electrothermal therapy is inconsistent. ^[18]

A 2009 evidence-based practice guideline from the American Pain Society stated that, “There is insufficient evidence to adequately evaluate benefits of …intradiscal electrothermal therapy…for nonradicular low back pain." ^[19]

REFERENCES

1. BlueCross BlueShield Association Medical Policy Reference Manual "Percutaneous Intradiscal Electrothermal (IDET) Annuloplasty and Percutaneous Intradiscal Radiofrequency Annuloplasty." Policy No. 7.01.72
2. TEC Assessment 2002. "Use of Implantable Cardioverter-Defibrillators for Prevention of Sudden Death in Patients at High Risk for Ventricular Arrhythmia." BlueCross BlueShield Association Technology Evaluation Center, Vol. 17, Tab 11.
3. TEC Assessment 2003. "Percutaneous Intradiscal Radiofrequency Thermocoagulation for Chronic Discogenic Low Back Pain." BlueCross BlueShield Association Technology Evaluation Center, Vol. 18, Tab 19.
4. Urrutia G, Kovacs F, Nishishinya MB, Olabe J. Percutaneous thermocoagulation intradiscal techniques for discogenic low back pain. Spine (Phila Pa 1976). 2007 May 1;32(10):1146-54.  PMID: 17471101
5. Andersson GB, Mekhail NA, Block JE. Treatment of intractable discogenic low back pain. A systematic review of spinal fusion and intradiscal electrothermal therapy (IDET). Pain Physician. 2006 Jul;9(3):237-48.  PMID: 16886032
6. Appleby D, Andersson G, Totta M. Meta-analysis of the efficacy and safety of intradiscal electrothermal therapy (IDET). Pain Med. 2006 Jul-Aug;7(4):308-16.  PMID: 16898940
7. Freeman BJ, Mehdian R. Intradiscal electrothermal therapy, percutaneous discectomy, and nucleoplasty: what is the current evidence? Curr Pain Headache Rep. 2008 Jan;12(1):14-21.  PMID: 18417018
8. Levin JH. Prospective, double-blind, randomized placebo-controlled trials in interventional spine: what the highest quality literature tells us. Spine J. 2009 Aug;9(8):690-703.  PMID: 18789773
9. Helm S, Hayek SM, Benyamin RM, Manchikanti L. Systematic review of the effectiveness of thermal annular procedures in treating discogenic low back pain. Pain Physician. 2009 Jan-Feb;12(1):207-32.  PMID: 19165305
10. Pauza KJ, Howell S, Dreyfuss P, Peloza JH, Dawson K, Bogduk N. A randomized, placebo-controlled trial of intradiscal electrothermal therapy for the treatment of discogenic low back pain. Spine J. 2004 Jan-Feb;4(1):27-35.  PMID: 14749191
11. Freeman BJ, Fraser RD, Cain CM, Hall DJ, Chapple DC. A randomized, double-blind, controlled trial: intradiscal electrothermal therapy versus placebo for the treatment of chronic discogenic low back pain. Spine (Phila Pa 1976). 2005 Nov 1;30(21):2369-77; discussion 78.  PMID: 16261111
12. Kapural L, Hayek S, Malak O, Arrigain S, Mekhail N. Intradiscal thermal annuloplasty versus intradiscal radiofrequency ablation for the treatment of discogenic pain: a prospective matched control trial. Pain Med. 2005 Nov-Dec;6(6):425-31.  PMID: 16336479
13. Barendse GA, van Den Berg SG, Kessels AH, Weber WE, van Kleef M. Randomized controlled trial of percutaneous intradiscal radiofrequency thermocoagulation for chronic discogenic back pain: lack of effect from a 90-second 70 C lesion. Spine (Phila Pa 1976). 2001 Feb 1;26(3):287-92.  PMID: 11224865
14. Kvarstein G, Mawe L, Indahl A, et al. A randomized double-blind controlled trial of intra-annular radiofrequency thermal disc therapy--a 12-month follow-up. Pain. 2009 Oct;145(3):279-86.  PMID: 19647940
15. Kapural L, Mekhail N. Novel intradiscal biacuplasty (IDB) for the treatment of lumbar discogenic pain. Pain Pract. 2007 Jun;7(2):130-4.  PMID: 17559482
16. Boswell MV, Trescot AM, Datta S, et al. Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. Pain Physician. 2007 Jan;10(1):7-111.  PMID: 17256025
17. National Institute for Health and Clinical Excellence.   [cited 02/25/2009]; Available from: http://www.nice.org.uk/Guidance/IPG83
18. National Institute for Health and Clinical Excellence.   [cited 07/15/2010]; Available from: http://www.nice.org.uk/Guidance/IPG81
19. 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 (Phila Pa 1976). 2009 May 1;34(10):1066-77.  PMID: 19363457

CROSS REFERENCES

Thermal Capsulorrhaphy as a Treatment of Joint Instability, Regence Medical Policy Manual, Surgery, Policy No. 100

Decompression of Intervertebral Discs Using Laser or Radiofrequency (DISC Nucleoplasty), Regence Medical Policy Manual, Surgery, Policy No. 131

Automated Percutaneous Discectomy; Regence Medical Policy, Surgery, Policy No. 145

Image-Guided Minimally Invasive Lumbar Decopression (IG-MLD) for Spinal Stenosis, Regence Medical Policy Manual, Surgery, Policy No. 176

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