ORLANDO, FL USA (UroToday.com) - The research group aims to determine if transfer of a primarily motor somatic nerve (femoral, F) to the anterior vesical branch of the pelvic nerve (PN) allows better reinnervation of the detrusor muscle after spinal root injury, compared to a primarily sensory nerve (genitofemoral, GF).
Return of function was determined using functional electrical stimulation (FES) and urodynamic observations. The conjecture was that transferring a nerve with more motor axons to the anterior vesical branch of the PN (F nerve) would more effectively reinnervate the detrusor muscle and restore function.
Four different surgeries were performed in 27 female mongrel hounds: 1) genitofemoral nerve transfer with vesicostomy (GF-NT-V: n=12); 2) genitofemoral nerve transfer without vesicostomy (GF-NT: n=5); 3) femoral nerve transfer with vesicostomy (F-NT-V: n=5); and 4) femoral nerve transfer without vesicostomy (F-NT: n=5). All bladders were decentralized by bilateral transection of all sacral roots that induce bladder contractions by intraoperative FES. GF nerves or two branches of the left F nerve were transferred to PN vesical branches, bilaterally. Bladder emptying in animals without vesicostomies was accomplished by Credé maneuver during the 6-month recovery period (242±6.2days).
Return of bladder function was observed as follows: 1) in 8 of 12 GF-NT-V dogs after direct stimulation of transferred GF nerve or lumbar spinal roots (mean detrusor pressure = 1.9±0.6 cmH2O); 2) in 4 of 5 GF-NT dogs after direct stimulation of transferred GF nerve or FES of lumbar spinal cord segment contributing to GF nerve origin (L2-3; mean detrusor pressure = 4.7±1.7 cmH2O); 3) in all 5 F-NT-V dogs after transcutaneous stimulation of transferred F nerve, or direct stimulation of lumbar cord segment or spinal roots contributing to F nerve origin (L2-5; mean detrusor pressure = 11.2±2.5 cmH2O); and 4) in 4 of 5 F-NT dogs after direct stimulation of transferred F nerve or FES of lumbar cord segment contributing to F nerve origin (mean detrusor pressure = 4.8±1.3).
The study group showed that although the bladder can be reinnervated by nerve transfer using either the GF or F donor nerve, the F-NT-V was the most efficient therapy. This surgical approach may be useful for patients with lower motor spinal cord injury to accomplish bladder emptying, improving their quality of life.
Presented by Sandra Gomez-Amaya, MD at the American Urological Association (AUA) Annual Meeting - May 16 - 21, 2014 - Orlando, Florida USA
Philadelphia, PA USA
Written by Achim Lusch, MD, University of California (Irvine), and medical writer for UroToday.com