Neuromodulation and the pudendal nerve Stefan De Wachter, MD, PhD, FEBU Professor of Urology University of Antwerpen, Belgium Chairman dept of Urology, UZA
Disclosures Consultant speaker: Astellas, Medtronic, Axonics, Allergan, Lilly, Solace, Pfizer, Menarini Research grants: Astellas, Medtronic
Neuromodulation and the pudendal nerve What is neuromodulation? Does neuromodulation work for pudendal neuralgia? Rationale to consider neuromodulation Current evidence
What is neuromodulation? Spinal cord stimulation Neuromodulation is any action that changes/modulates pre-existing neural activity Sacral to influence the physiological behavior of an organ Tibial neurostimulation è direct effect (SARS Brindley) Pudendal Electrical chemical magnetic stimulus Sacral Pudendal Tibial Nerve Stimulation Botulinum toxin Perineal Trans sacral
Neuromodulation and the pudendal nerve What is neuromodulation? Does neuromodulation work for pudendal neuralgia? Rationale to consider neuromodulation Current evidence
Why could it be considered as treatment or adjunct Sacral Pudendal Tibial (Spinal cord)
Why could it be considered as treatment or adjunct Sacral Pudendal Tibial
Presacral plexus Sensory nerves S2, S3 Cutaneous branches buttock, thigh Pudendal S2, S3, S4 Sensory to genitalia Muscular branches perineal muscles, external urethral and anal sphincter Pelvic splanchnic S2, S3, S4 Pelvic viscera via hypogastric and pelvic plexus Motor nerves S3, S4 Levator ani and coccygeus muscle From Grants Atlas of Anatomy
Proper Tined Lead Placement ² Following natural nerve path ² Appropriate responses on all electrodes ² Motor response under 2 V
Acute S3 stimulation Sensory response Motor response Anal wink No direct motor contraction Reflex mediated contraction Early late component Pudendal afferent Survives spinalization Schurch et al. World J Urol 20(6):319,322, 2003
Chronic S3 stimulation Modulates pudendal afferent transmission Malaguti et al. J Urol 170:2323-2326,2003
Sacral neuromodulation Conventional indications / Experimental Overactive bladder symptoms Urgency Incontinence Urinary retention Faecal incontinence Constipation Pelvic pain Sexual dysfucntion
Longterm Results Conventional indications Prospective ww, multicenter - 5 year FU 152 pt s: 96 UUI (63.2%) 25 (16.4%) urgency-frequency and 31 (20.4%) urinary retention 105 pt s had 5 year data There was a high correlation between 1- and 5-year success rates: 84% of patients with UUI, 71% with UF and 78% with UR who were successfully treated at 1 year continued to have a successful outcome after 5 years Mean number AE resulting in surgical intervention occurred respectively in 19.9% and 39.5% of patients at 1-year and 5-year follow-up Van Kerrebroeck et al. J Urol 178:2029-2034, 2007
Current scientific data Sacral neuromodulation and pelvic pain Everaert et al. 2001 Chronic pelvic pain excluding IC/BPS (n=26) significant pain relief in 62% (n=16) 42% received implant (n=11) 36mo FU 73% satisfied with treatment (n=8)
Current scientific data Sacral neuromodulation and pudendal neuralgia Only 1 case reports available Robotic assisted radical hysterectomy right side Nantes criteria positive Positive response nerve blocks / local anesthetics pudendal nerve Bilateral S3 S4 lead ultra pulse generator Successful outcome 4y FU
Why could it be considered as treatment or adjunct Sacral Pudendal Tibial
Extrapelvic stimulation
Pudendal nerve stimulation Peters KM et al. Neurourol Urodyn. 2005;24:643-647. Spinelli M, et al. Neurourol Urodyn. 2005;24(4):305-9.
Pudendal nerve stimulation Final placement of electrodes
Pudendal nerve stimulation Results conventional indications Peters et al. Neurourol Urodyn 24: 643-647, 2005; Peters et al. Neurourol Urodyn 29: 1267-1271, 2010 Sacral vs Pudendal nerve Stimulation 30 patients with both leads PNS è 63% improvement in complaints SNS è 46% improvement in complaints 79% chose pudendal over sacral stimulation 93% sacral failures respond to pudendal 17/30 (57%) with pelvic pain showed marked improvement in pain
Current scientific data Pudendal neuromodulation and pudendal neuralgia Carmel et al. Int Urogynecol 2010 3 patients fulfilled Nantes Criteria Case 1: 64y female >30y ss/ - Pain reduction 80% - FU 2 years Burning pain genitalia, perineum and rectum Case 2: 44y female ; > 7y ss/ - nearly painfree FU 2 years Burning sensation anus and left buttock Case 3: 43y female ; > 20y ss/ - Pain reduction >80% FU 2 years
Current scientific data Pudendal neuromodulation and pudendal neuralgia Peters et al. LUTS 2015 19 patients pudendal neuralgia retrospectively reviewed 55y age 18/19 already had nerve blocks 15/18 experienced some relief 19/19 successful test IPG implanted 3 complete relief / 3 almost complete / 10 significant / 3 small relief 5 explanted after 3 years
20 patients with CPPS >3/5 Nantes criteria not mentioned how many
Why it could be considered as treatment or adjunct Sacral Pudendal Tibial
Procedure Tibial nerve sends afferents through the sacral nerve plexus Studied since the 1980 s for the treatment of OAB
Peters et al. J Urol 183: 1438, 2010 SUmiT trial Sham controlled trial Endpoint GRA Moderate improvement
Peters et al. J Urol 189: 2194-2201, 2013 STEP study 36 mo results following SUmiT 60 responders SUmiT eligible 50 consented to study 29 (58%) completed 36 mo (=26% of initial 110 patients) Treatment schedule tailored to patient s need Endpoint GRA moderate improvement 97% 76% 12 months 43 47 7 24 months 40 46 14 36 months 45 41 14 0% 20% 40% 60% 80% 100%
Istek et al. Arch Gynecol Obstet 290: 291-298, 2014 Current scientific data Tibial nerve stimulation and chronic pelvic pain RCT 16 PTNS vs 17 control Chronic pelvic pain excluding IC/PBS PTNS 2/16 (13%) cured 7/16 (44%) improved P<0.05 Control 2/17 (12%) improved Present Pain Intensity VAS 9 8 7 6 5 4 3 2 1 0 PTNS Control Baseline 12w 6mo
Implantable tibial nerve stimulation
Neuromodulation and the pudendal nerve What is neuromodulation? Does neuromodulation work for pudendal neuralgia? Rationale to consider neuromodulation Current evidence Currently only limited data available Pudendal neuromodulation seems most promising Lots of questions to be answered Monotherapy or adjunct therapy? Standardized placement electrodes? Longterm effect?
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