610 likes | 645 Views
MBB are Necessary for Appropriate Patient Selection Prior to RFL. OR " Medial branch blocks before radiofrequency denervation: more is better" J. Scott Bainbridge, M.D. November 18, 2012: ASRA - New Orleans March 9, 2012 McCulloch Spine Conference.
E N D
MBB are Necessary for Appropriate Patient Selection Prior to RFL OR " Medial branch blocks before radiofrequency denervation: more is better" J. Scott Bainbridge, M.D. November 18, 2012: ASRA - New Orleans March 9, 2012 McCulloch Spine Conference
J. Scott Bainbridge Financial Relationship Disclosure Company: Nimbus Concepts Spine LLC Type of Relationship: Director of Research – Equity interest
J. Scott Bainbridge Professional Relationship Disclosure Society: ISIS AAPMR NASS AAPM AMA others Type of Relationship: Board of Directors Member Member Member Member
Objectives Attendees will be able to demonstrate: an understanding of the basic and clinical science supporting the use of medial branch radiofrequency lesioning to treat LBP of LZJ origin. a working knowledge of the advantages of the 2 MBB RFL patient selection paradigm towards enhancing clinical outcomes. an understanding of the concepts and impact of “value” with respect to medical policy decisions. an appreciation of the recent history of LZJ policy decisions and the context which they provide for guiding future pain societies’ practice recommendations
LZJ – Anatomy of Innervation Bogduk • The anatomy of.. articular nerves and their relationship to facet denervation; J Neurosurg 1979 • Clinical Anatomy of the Lumbar Spine and Sacrum; Elsevier 1987, 1991, 1997, 2005 • Lau, Mercer, Bogduk; The surgical anatomy of lumbar medial branch neurotomy. Pain Med 2004.
Z-joint MAL Lateral br Intermed br Borrowed from Nik Bogduk
LZJ - Medial Branch Blocks • Effective anesthesia of LZJ – Validation Study (Kaplan 1998) • Record pain with provocation before and after • Single MBB false positive rate = 35% (Dreyfuss Spine 2000; Manchikanti, BMC Musculoskeletal Disorders 2004) • Technique important • 0.2+ cc contrast live fluoro (venous uptake > false negative) • 0.3-0.5 cc anesthetic • Rotate C-arm obliquely to avoid striking SAP
LZJ – Intra-Articular Injections Not validated as diagnostic tool Not predictive of RFN outcome (Reiz-unpublished) Lack of evidence for long term efficacy (Bogduk 2005, Chou 2009) • Based on two RCTs • Carette; NEJM 1991 • Lilius; JBJS-Br 1989 May be a palliative role (Dolan, Br J Rheumatology; Pneumaticos, Radiology 2006)
Medial Branch Radiofrequency Neurotomies (RFN) - Lumbar Medial branch block and RFN techniques described in: ISIS Practice Guidelines: Spinal Diagnostic & Treatment Procedures. Bogduk (ISIS Standards Committee) 2004 Lau P, et al. The surgical anatomy of lumbar medial branch neurotomy (facet denervation). Pain Med 2004
Z-joint MAL Lateral br Intermed br Borrowed from Nik Bogduk
5 mm tip A 10 mm tip would be ideal to lesion along target length of the nerve Borrowed from Nik Bogduk
The right L5 dorsal ramus, view from the right, dorsally, peering over the iliac crest. L5 medial branch L5-S1 z joint mal communicating branch to S1 L5 dorsal ramus Borrowed from Nik Bogduk iliac crest
A narrative review of lumbar medial branch neurotomy for the treatment of back painBogduk, Dreyfuss, Govind; Pain Med 2009
A narrative review of lumbar medial branch neurotomy for the treatment of back painBogduk, Dreyfuss, Govind; Pain Med 2009 Invalid lumbar RF neurotomy RCTs used in systematic reviews, guidelines, policy formulation • American Pain Society (Chou 2009) • Cochrane, NICE, ACOEM, Hayes
Cohen 0, 1, 2 Block Cost-Effectiveness Study Comparative Cost-Effectiveness of 0, 1, or 2 MBB before LZJ – RFN Cohen, et al. Anesthesiology 2010 151 screened and randomized to groups RFN of 51/51 of 0 block group; 19/50 of 1 block; 14/50 of 2 bl Parallel single lesion with 20 gauge/ 10mm active tip Denervation Success Rates (> 50% relief) at 3 months: • 0 mbb - 33% (more get better; costs less) • 1 mbb - 39% • 2 mbb - 64%
Reiz-Unpublished RCT 100 older pts (age 65-85) with z-jt arthropathy and moderate to severe pain (>5 NRS) were selected Randomized to three diagnostic groups • Radiological and clinical grounds only • >80% relief for >4 hrs after a single 0.5% marcaine mbb • >80% relief for >4 hrs after a single 0.5% marcaine mbb and no response to a placebo (NaCl) mb injection
Reiz-Unpublished RCT RFN performed with a 10 mm active tip electrode with 4-6 lesions using a parallel technique (in the groove and up the lateral wall of the SAP) Success defined as >50% pain relief from baseline pain
65-85 yrs Unilateral NRS > 5/10 200 30 60 100 Clinical Radiological Single MBBs bupivacaine Placebo controlled MBBs saline vs bupivacaine > 80% > 80% RF RF RF 30 33 37 8 21 31 8 21 31 10 21 31 0.33 0.55 0.83 0.16 – 0.50 0.38 – 0.72 0.71 – 0.95 95% 0.387 – 0713 0.714 – 0.946 94% 2 months 6 months 12 months >50% RELIEF Borrowed from Paul Dreyfuss
Dreyfuss LMB RFN Prospective Audit(Dreyfuss, et al. Spine 2000) 41 screened 15 passed comparative blocks >80% relief and enrolled 16 gauge RF needle placed parallel to MB Lesions confirmed with EMG Outcomes: VAS, McGill, Roland-Morris, SF-36, NASS treatment expectations, functional tests, Follow-up: 6 weeks, 3, 6, and 12 months 13/15 with 60% or > relief (87% success); 60% w >80%relief
2 Blocks Are Better Than None (or One) 2 Blocks No Blocks
If a 0 block paradigm was adopted… …what would be the consequences?
Consequences - Utilization Utilization rises 3-400% over dual block paradigm.
Cost/Utilization – Single Blocks If dual comparative blocks (specificity 0.88), then 252 RF patients (84 w/out disease) $3,000 per RFL x 1,000 (0 block); 545 (1 block); 252 (2 block) 0 Block = $3,000,000; 1 Block = $1,635,000; 2 block = $756,000
Consequences – Utilization and Cost Utilization and cost of LMB RFN would rise at least 3-400%. Utilization of code 64622/64623 could rise > 400% due to: • Vague + lax adherence to indications Over-utilization will lead to susceptibility to OIG/Policymaker/Payer scrutiny • Context of total interventional LZJ care/costs may be ignored Combined with poor group mean outcomes for RFN treatment, this could lead to loss of coverage/access.
Increases in lumbosacral injections in the Medicare population: 1994 to 2001 Friedly, Chan et al. 2007
OIG Report 2008 Sampling of <1% of 2006 facet procedures (64470, 64472, 64475, 64476 – C, T, and L-spine facet IA and MBBs) Office, Ambulatory surgery center (ASC), and hospital outpatient department (HOPD) based procedures Utilization increasing dramatically Error rate high for documentation, billing, and payment OIG 2008
Consequences - Utilization Pain / Interventional / Spine Societies MUST present a unified message regarding appropriate use criteria (AUC) • To Policy Makers • To Providers • To Patients/Consumers
Consequences - NNT B Number Needed to Treat = 1 / success rate – placebo rate Bogduk/Polly Spineline 2010
Number Needed to Treat (NNT) Placebo rates of 34-39% in interventional RCTs: Valat, Van Wijk, Pauza, Yelland. Cohen 0 Group NNT would rise to infinity, as would cost per attributable success.
Consequences – Cohen’s Cost Analysis Only an incremental, not exponential, difference in total cost per group or cost per successful outcome. Assumes that 3 month outcomes will continue to 1 year. Cost/group or cost/success argument loses credibility when NNT, OUTCOMES and VALUE are considered. Change in message undermines efforts with policy makers.
VALUE Is the improvement with treatment worth the cost of that treatment?
Cost – Utility Analysis Utility score: 0 for death; 1 for perfect health Societal health state values directly derived using methods such as: gamble, time trade-off, VAS Cost-utility analysis used to assess relative value of treatments Cost/change in utility score with treatment = cost-utility ratio Utility scores used to calculate Quality-Adjusted-Life Years (QALYs) • QALY = Δ Utility X Effect Time (Years) Carreon, et al. Spine 2009
Utility Indirect measures of utility: • Quality of Well Being Scale • EuroQOL EQ-5D • Health Utilities Index • Short Form (SF)-6D Estimation of SF-6D using ODI scores: • SF-6D = 0.78275 - 0.00518(ODI) • Pearson=0.82 Carreon et al. Spine 2009