ABSTRACT
Immunohistochemical study have been made to examine the autonomic innervation of the human vas dererens following vasectomy one to 7 years previously. Samples from sites on the proximal (testicular) and distal (urethral) sides of the original vasectomy have been compared with control specimens as to the arrangement and distribution of autonomic nerves containing vasoactive intestinal polypeptide (VIP), catecholamine, substance-P and enkephalin. In contrast with tissues from the urethral portion and from controls, the testicular specimens revealed a marked reduction in the catecholeminergic innervation of the muscular layer. In addition VIPergic nerves distributed at the subepithelial layer were nearly absent from the testicular side of the vas deferens. The degrees of denervation were independent of the obstructive interval between vasectomy and vasectomy reversal. Substance-P and enkephalin containing nerves were rarely found from both sides of the vas deferens. Therefore, these findings suggest that the consequences of denervation of vas deferens may play an important role in those patients in whom infertility persists despite evidence of satisfactory mechanical continuity achieved by vasectomy reversal.