Reconstruction of Severed Ventral Roots Innervating the Urinary Bladder:An Experimental Study in Cats

Abstract

In an experimental study on 12 adult cats, the ventral roots innervating the detrusor muscle of the urinary bladder were transected and anastomosed using the Millipore tubulation technique. In one series one pair of the three sacral ventral roots previously innervating the detrusor were reconnected. In another series one pair of lumbar ventral roots were anastomosed to one pair of sacral ventral roots, thus creating a non-physiological efferent pathway to the denervated bladder. The functional restitution of efferent fibers to the denervated bladder was assessed by the return of the micturition reflex. In all 10 animals where root anastomoses were performed the micturition reflex returned after regeneration periods ranging between 4 and 7 months. In controls, where no anastomoses were performed or where functionally regenerated roots were transected, the micturition reflex was permanently abolished. The results were further evaluated by bioelectrical and histological methods. The mechanisms of restoration of an autonomic function by regeneration of somatic efferent fibers as well as the rearrangement of the spinal reflex pattern after heterogenous anastomoses are discussed. A possible clinical application of the technique is mentioned.