Urinary bladder reinnervation.

The ability of mixed spinal nerve roots to regenerate and reinnervate the urinary bladder was examined in young adult female cats. Using microsurgical technique, a unilateral extradural spinal nerve root anastomosis of a lumbar (L7) to a sacral root (S1) either with or without a nerve graft was performed. Remaining ipsilateral sacral roots were transected. The contralateral normal sacral roots remained intact and allowed the animals adequate urination during the period necessary for axonal regeneration. At the time of restudy seven months later, stimulation of the anastomosed nerve root proximal to the anastomosis (isolated from the spinal cord) elicited a bladder contraction. Significant lumbar axonal regeneration was substantiated by compound action potentials recorded across the anastomosis. In addition, redirection of axons from a lumbar to a sacral distribution was demonstrated. The contralateral normal sacral roots provided control cystometric and electrophysiological data against which responses from the previously anastomosed nerve roots were compared. In conclusion, significant bladder reinnervation can occur after an anastomosis of a lumbar and sacral root with or without a nerve graft. This technique, or variations thereof, may have a clinical role in selected patients with neurogenic bladder dysfunction to reinnervate the bladder and restore central control.