Presentation Authors: Danielle M. Salvadeo*, Ekta Tiwari, Nagat Frara, Lucas Hobson, Alan S. Braverman, Mary F. Barbe, Michael R. Ruggieri, Sr., Philadelphia, PA
Introduction: 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 cystometry assessed awareness of a bladder fullness and ability to empty.
Results: 3/4 animals in Group 1 showed micturition postures up to 12 months postoperatively, with the fourth exhibiting an intermediate posture unlike the typical micturition posture. While status of bacteriuria for three animals was unknown, confirmed bacteriuria in one animal coincided with observed postures. We saw an increase in micturition postures with the presence of bacteriuria in 2/3 animals in Group 2, prior to reinnervation, which disappeared with successful antibiotic clearance. At least three months after reinnervation, all animals in Group 2 exhibited micturition postures in their home cages. Group 3 control animals showed micturition postures and bladder emptying after removal of catheter. During awake cystometry, no animals in Group 1 appeared distressed by bladder filling. In contrast, 1/3 animals in Group 2 tested at 6 and 7 months after nerve reinnervation procedures made vocalizations that suggested discomfort, and therefore sensation, after filling. The animal then voided bladder after removal of catheter.
Conclusions: Although we predicted a loss of sensation after transecting the sacral roots and dorsal roots of L7, we observed frequent micturition postures suggestive sensation, possibly due to concomitant UTIs rather than bladder fullness. Furthermore, observations made during video recording and awake cystometry suggest that the nerve transfer reinnervation procedure lead to recovered sensitivity of bladder fullness.
Source of Funding: NIH: NIH-NINDS NS070267 to MRR and MFB