Combination Techniques: NANS 2010 Marc A. Huntoon, M.D. Professor of Anesthesiology Mayo Clinic, Rochester MN 3076681-1 Disclosures • Investigator initiated research support from Boston Scientific • Concluded involvement in multicenter trial for Medtronic supported research 3076681-2 Spinal Cord Stimulation • Doesn’t always work • Sometimes it works for a while, but the patients seem to exhibit a “tolerance” • Are there neuro-humeral combinations that might improve SCS outcomes? • Would combining different stim types be helpful? 3076681-3 Multi-modal Analgesia • Is combination therapy the future? • If so, which combinations are the right ones? 3076681-4 Fig. 1. Spinal Cord Stimulation: Exploration of the Physiological Basis of a Widely Used Therapy. Linderoth, Bengt; Meyerson, Bjorn Anesthesiology. 113(6):1265-1267, December 2010. DOI: 10.1097/ALN.0b013e3181fcf590 © 2010 American Society of Anesthesiologists, Inc. Published by Lippincott Williams & Wilkins, Inc. 2 3076681-5 Possible Combinations • SCS and PNS • SCS and Subcutaneous Field Stimulation • PNS and TENS • SCS and IT infusion • PNS and perineural/DRG infusion • New Stimulation Targets 3076681-6 Which is greater: Parent, offspring, or combination? 3076681-7 GABA-ergic Mechanisms • Addition of baclofen, a GABA-b agonist converts non-SCS responders into responders • Follow up study of combination of IT baclofen with SCS in humans Cui JG; Linderoth B; Meyerson BA. Effects of spinal cord stimulation on touch-evoked allodynia involve GABAergic mechanisms. An experimental study in the mononeuropathic rat. Pain 1996; 66:287-95. 3076681-8 Cholinergic SCS Mechanism • Basal release of acetylcholine (ACH) reduced in nerve injured rats • Response to SCS blocked by atropine & antimuscarinic agents in rats • SCS effect at least partially due to cholinergic mechanisms Schectmann G, Song Z,Ultenius C, Meyerson B, Linderoth B. Pain 2008;139:136-45. 3076681-9 Cholinergic Mechanisms of SCS • Responders to SCS release significantly increased amount of acetylcholine in response to SCS Schectmann G, Song Z,Ultenius C, Meyerson B, Linderoth B. Pain 2008;139:136-45. 3076681-10 3076681-11 Immune Modulation: Cytokine Antagonists Vallejo R, et al. Pain Practice 2010;10:167-84. 3076681-12 Perineural Clonidine • Α-2 adrenoceptors cluster at sites of peripheral nerve injury • Perineural clonidine has prolonged effect decreasing hyperalgesia • Clonidine is immune modulator, i.e. blocks cytokines (TNF-α), IL-1β, IL-6 Lavand’homme P, et al. Anesthesiology 2002;97:972-80. Romero-Sandoval A. Eisenach JC. Anesthesiology 2006;104:351-5 3076681-13 Transforaminal Clonidine RCT of transforaminal epidural (TFE) clonidine 200 or 400 mcg. versus triamcinolone 40 mg. Burgher AH, et al. Spine 2011,in press 3076681-14 Percutaneous PNS: Procedural Prerequisites • Ultrasound-guided nerve block ( clonidine 100-200 mcg. in 0.25% bupivacainecomplete or excellent relief • Psychological screen (implant committee) • Failed more conservative therapies • Pain in one nerve distribution • Capable of understanding system requirements 3076681-15 Anatomy Lab 3076681-16 Needle and Electrode Deep to Nerve Radial nerve approach Nitinol Wire around Ulnar Nerve 3076681-18 Peritrode Over Nitinol Wire 3076681-19 Peritrode Placement 3076681-20 + + Fascicle 3076681-21 Drug Elution: Combine PNS and Pharmaceuticals ( e.g. clonidine) 3076681-22 Back Pain in a Post-laminectomy Syndrome Patient Which orientation of electrodes is superior? Is a wide spaced electrode better than a closely spaced one? How many leads is “reasonable”? What is the mechanism of analgesia? Is there a way to optimize location of Leads? 3076681-23 Peripheral Field Stimulation • • • • • 3 Cases of subcutaneous stim implant SCFS for 1-2 hours/day: 12-24 hrs relief Failed TCA’s, pregabalin, etc. Patients had all failed TENS previously Required low frequency 2-10 Hz, at low amplitude (1-3 mA) and narrower pulse widths (100 ms) than typical of SCS • 1-3 year improvement in small series Goroszeniuk T, Kothari S, Hamann W. Reg Anesth Pain Med 2006;31:168-71. 3076681-24 Subcutaneous Field Stimulation for Back Pain • Longstanding FBSS • Predominately back pain • Implanted subcutaneous peripheral field stimulation electrodes in patients back • 1 Year outcome good Krutsch JP, McCeney MH, Barolat G, et al. Neuromodulation 2008;112-115 3076681-25 Subcutaneous PNS for FBBS Krutsch JP, McCeney MH, Barolat G, et al. Neuromodulation 2008;112-115 3076681-26 Combined PNFS and SCS • 20 patients with combined back and leg pain • Retrospective Chart Review • Underwent simultaneous placement of transverse PFS at site of maximal pain as well as SCS, some after SCS alone failed to relieve back pain • Some leads placed at cluneal neuroma or other sensitive scar sites Bernstein CA, Paicius RM, Barkow SH. Neuromodulation 2008;11:116-23. 3076681-27 3076681-28 Interlead Communication: “Crosstalk” 1) 20 patients; > 60% axial back pain 2) Epidural Octrode (guarded cathode) 3) perpendicular quadripolar SC lead at site of greatest back pain (alternating cathode/anode) 4) Programs: #1 Epidural octrode alone; #2 Subcutaneous lead alone; #3 Both leads simultaneously Mironer YE, Hutcheson JK, et al. Neuromodulation 2010; E-pub ahead of print 3076681-29 Interlead Communication “Crosstalk” Study Part 1: Results • 6 SC leads crossed midline; 14 leads unilateral • 17/20 had FBS syndrome (1 pt. DNR) • 15/19 picked program #3 favorite • 3/19 Program #1 (SCS) was favorite Mironer YE, Hutcheson JK, et al. Neuromodulation 2010; E-pub ahead of print 3076681-30 Interlead Communication “Crosstalk” Study Part 2 • Program 1:SCS and PNFS independently programmed • Program 2: Epidural Anode + PNFS cathode • Program 3: Epidural Cathode + PNFS Anode Patients “blinded”; All PNFS contacts active, only selective (sweet spot) contacts for SCS Mironer YE, Hutcheson JK, et al. Neuromodulation 2010; E-pub ahead of print 3076681-31 ++ ++++++++ 3076681-32 “Crosstalk” Study Part 2: Results • All but two could feel PNFS in P #1 • P #2, 4 patients same as #1; 6 patients with larger area of stim; 10 patients with wide coverage • P #3, All but one patient with wide axial coverage • Most popular cycling of P#1 and 3 Mironer YE, Hutcheson JK, et al. Neuromodulation 2010; E-pub ahead of print 3076681-33 Summary • Substantial early excitement for SCS+ SCFS • Some evidence for IT agents + SCS • Possible role for PNS + Perineural immune modulation • Upcoming Study of PNS and SCS • Emerging role of DRG 3076681-34 Lost? J Wallace PA huntoon.marc@mayo.edu 3076681-35