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INTRODUCTION AND OBJECTIVE:This study determined the effect of pelvic organ long-term decentralization and reinnervation one year later on the contribution of muscarinic and purinergic receptors to...

INTRODUCTION AND OBJECTIVES:We aim to surgically reinnervate a lower motor neuron neurogenic bladder via obturator-to-pelvic and sciatic-to-pudendal nerve transfer. Behavioral observations provide the most global assessment of functional recovery. We sought to determine whether observed micturition postures disappear in decentralized animals and reappear after reinnervation.METHODS:Three groups of female canines were used: 1) Long-term survival (12 months) after transection of all ventral and dorsal sacral roots, the dorsal roots of L7 and hypogastric nerves, bilaterally (n=4); 2) Procedures described in Group 1, followed by obturator-to-pelvic nerve and sciatic-to-pudendal nerve transfer (n=3); 3) Unoperated control animals (n=3). Micturition postures were monitored for 24 hours at monthly intervals via video recording. Bacteriuria was tracked midway through the study with urine Multistix test strip assays, body temperature, and cultured urine specimens by a commercial clinical laboratory. Awake cystomet...

INTRODUCTION AND OBJECTIVES:Carbachol, a mixed muscarinic and nicotinic agonist similar to acetylcholine, is often used for in-vitro bladder contraction with the implicit assumption that it causes ...

INTRODUCTION AND OBJECTIVES: Although we previously demonstrated that transfer of the genitofemoral nerve to vesical branches of the pelvic nerve reinnervates the canine urinary bladder after bladder, urethral sphincter and anal sphincter denervation by transection of the S2 and S3 spinal roots, reinnervation of the sphincters requires additional nerve transfer strategies. The goal of this investigation is to determine the feasibility of reinnervation of the urethral and anal sphincters by transfer of femoral motor nerve branches to pudendal nerve branches for functional sphincter reinnervation in a canine model and clinical feasibility in a cadaver study. METHODS: After bladder, urethral sphincter and anal sphincter denervation in 3 female canines, femoral nerve branches were mobilized bilaterally, attached by end to end anastomosis to the distal cut ends of the pudendal nerves as they emerged from Alcock’s canal and implanted with nerve cuff electrodes interfaced to radiofrequency micro-stimulators (RFMS). Eleven cadavers were dissected bilaterally to expose pudendal and femoral nerve branches. Pertinent landmarks and distances that could be used to locate these nerves were assessed and measured, as were nerve cross sectional areas. RESULTS: Activation of the 5 of 6 implanted RFMS induced increased urethral and anal sphincter pressure with stimulus intensity of 15 mAmp or greater. Retrograde tracing studies demonstrated labeling of the upper lumbar ventral and lateral horns of the spinal cord with fast blue from the urethra and fluoro ruby from the anal sphincter, 8% of which were dual labeled. In the cadavers, a long motor branch of the femoral nerve was followed into the distal vastus medialis muscle for a distance of 17.4 0.8 cm, split off from the main femoral nerve trunk and transferred medially and superiorly to the pudendal nerve in Alcock’s canal, a distance of 13.6 0.71 cm. This was performed using a perineal approach. The cross sectional area of the pudendal nerve was 5.64 0.49 mm, and the femoral nerve motor branch at the suggested transection site was 4.40 0.41 mm. CONCLUSIONS: In the canine model, both urethral and anal sphincters can be reinnervated with femoral to pudendal nerve transfer. In the cadaver study, use of a femoral nerve motor branch to the vastus medialis muscle for heterotopic nerve transfer to the pudendal nerve is surgically feasible, based on anatomical location and cross sectional areas.

calculated as the number of original AUS implants performed prior to the index patient’s surgery. Multivariable logistic regression models were used to examine the association between experience and reoperative rates adjusted for case-mix. RESULTS: Most surgeons included in our analyses performed fewer than 5 AUS implants (n 4757; 59%); 23% (n 1813) had a lifetime history 10 or more prior cases and 2% (n 134) performed 50 or more AUS implants. The analysis of any reoperation within 5 years included 40,347 male patients treated with an AUS between 1988 and 2003. Nearly 1 in 4 (n 9098; 23%) underwent reoeperative surgery. There was a slow decrease in reoperative rates with increasing surgeon experience (p 0.020). The risk of reoperation for a surgeon with 5 prior cases was 24%, which decreased to 18% for a surgeon with 100 prior implants (absolute risk difference 5.9%; 95%CI 1.3%, 10.1%) and to 13% for a surgeon with 200 prior implants (absolute risk difference 10.7%; 95%CI 2.6%, 16.6%). Two-thirds of contemporary patients saw surgeons who had done 25 or fewer AUS implants; only 9% saw a surgeon with 100 or more prior procedures. The figure gives predicted 5 year probability of reoperative surgery plotted against surgeon experience. The overlaying density plot shows the distribution of patients by surgeon experience in 2000–2008. CONCLUSIONS: There is a clear and obvious disparity between the learning curve for AUS surgery and typical surgeon experience, suggesting a considerable burden of avoidable reoperations. Attempts to speed up the learning curve, perhaps though advanced or apprenticed training, are urgently needed.