EBM of Intradiscal Electrothermal Therapies Ray M. Baker Clinical Professor of Anesthesiology University of Washington NASS, Spring Break 2006, Back to The Evidence Reporter: Yuan-Chun Huang

EBM Hierarchy Synthesis (e.g. Cochrane) Studies RCT > Case control > Case Series > RCT > Case control > Case Series > Retrospective > Case reports Retrospective > Case reports

Levels of Evidence: Cochrane. Level A: strong research-based evidence provided by generally consistent findings in multiple high-quality RCTs;. Level B: moderate research-based evidence provided by generally consistent findings in one high-quality RCT plus one or more low-quality RCTs, or generally consistent findings in multiple low-quality RCTs;. Level C: limited or conflicting research-based evidence provided by one RCT (either high or low quality) or inconsistent findings in multiple RCTs;. Level D: no research-based evidence i.e., no RCTs.

IDET

IDET: Rationale Proposed mechanism of action: Stiffening and strengthening of the collagen? Deactivation of inflammatory enzymes / chemicals? coagulation of posterior annular nociceptive pain fibers?

IDET Evidence Synthesis – 1 Chou AJPMR 2005 ( Chou LH, Lew HL, Coelho PC, Slipman CW: Intradiscal electrothermal annuloplasty. Am J Phys Med Rehabil 2005;84: ) Studies # RCTs – 2 (Pauza and Freeman) # RCTs – 2 (Pauza and Freeman) # Several prospective case control studies and cohort control studies. # Several prospective case control studies and cohort control studies. # Several prospective observational, retrospective studies, and case series. # Several prospective observational, retrospective studies, and case series.

Pauza, TSJ 2004 Pauza, Howell, Dreyfuss et al. A randomized placebo-controlled Trial of IDET for the treatment of discogenic LBP. The Spine J 2004; Volume 4: Issue 1, A randomized placebo-controlled Trial of IDET for the treatment of discogenic LBP. The Spine J 2004; Volume 4: Issue 1,

Pauza, TSJ ,523 patients inquired about the study; after phone interview 1,360 underwent an interview and physical examination 260 met initial criteria and underwent discography 64 patients eligible after discography. 37 randomized to IDET. 27 randomized to sham.

Pauza, TSJ 2004 Patient selection criteria: Discogenic LBP > 6 months in duration. LBP > leg pain. Less than 20% disc height narrowing on lateral plain film radiographs. Beck depression scale score less than 20. No co-morbid conditions.

Pauza, TSJ 2004.Exclusion Criteria #.Previous lumbar spine surgery #.Abnormal neurological exam #.Radicular pain #.Chronic medical conditions #.Central or foraminal stenosis #.Intervertebral disc herniations > 4 mm. #.Cervical or thoracic pain > than 2/10. #.Gait altering LE conditions

Pauza, TSJ 204 IDET. # Catheter passed circumferentially to completely cover the posterior anulus (bilateral passes if needed) # Catheter heated to final temperature of 90° C via the standard 16.5 minute protocol

Pauza, TSJ 204 Sham. # Introducer passed to postero-lateral aspect of disc, but disc never entered # 16.5 mins passed, sounds/images of IDET # Sedation (versed) used as in IDET group

Pauza, TSJ 204 Blinding process was maintained- approximately 75% in both groups believed they had the real treatment 8 patients (12.5%) excluded. (including: unacceptable catheter placement, died, concurrent illness, non-compliant with follow up, drug abuse)

Pauza, TSJ 204 SF 36: (The Medical Outcome Study 36-item short-form health survey ) no statistically significant difference. no statistically significant difference. Oswestry disability scale: IDET > placebo (p=0.038) VAS Mean ↓ 2.4 IDET vs. 1.2 Sham 50% of patients unchanged.

Pauza, TSJ 204

IDET is not a placebo treatment. However, after a very rigorous screening process IDET substantially reduces pain in only 1 of 5

Freeman, Spine 2005 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. A Randomized, Double-Blind, Controlled Trial Intradiscal Electrothermal Therapy Versus Placebo for the Treatment of Chronic Discogenic Low Back Pain. Spine 2005; Volume 30( Number 21): pp Spine 2005; Volume 30( Number 21): pp

Freeman, Spine 2005

Inclusion Criteria: # LBP > LE pain # LBP > LE pain # Disc Height > 50% # Disc Height > 50% # 1 or 2 level disc degeneration # 1 or 2 level disc degeneration # Discography (+) with normal control # Discography (+) with normal control # No prior surgery # No prior surgery # Sitting Tolerance > Standing tolerance # Sitting Tolerance > Standing tolerance # Normal neurologic exam # Normal neurologic exam

Freeman, Spine 2005

No statistically significant difference in any of the outcome measurements. Even looking at subsets, did not result in any subset reaching a p value close to Zero placebo Zero placebo

Levels of Evidence: IDET Equivocal. Level C: limited or conflicting research- based evidence provided by one RCT (either high or low quality) or inconsistent findings in multiple RCTs;

Pauza et al may well have shown statistical significance between their two groups, but Freeman et al would argue that this does not necessarily equate to clinical significance. One thing is clear from the literature: that highly selected groups of patients are required to show only marginal benefit from the procedure and that IDET is not beneficial for the vast majority of patients with CDLBP.

Thanks for attention!