Innervation of the Rabbit Ductus Deferens after Vasectomy and Vasovasostomy1

Innervation of the Vas Deferens and Its Importance for Vasectomy and Vasovasostomy

“…Vasec tomy in rats caused a disappearance of adren ergic innervations below the site of vasec tomy [14]. Comparable data were recently obtained in rhesus monkeys [11].…”

“…Prins and Zanefeld [17] showed in rabbits that sperm must be trans ported through the ductus deferens during sexual stimulation, prior to ejaculation. Alex ander et al [11] found that 6 weeks after vasovasostomy the a-adrenergic innervation of the testicular end of the vas had not returned to normal density and that the cau dal epididymis had only reached 15-20% of its normal innervation density. They believe that these facts might account in part for the discrepancy between low pregnancy rate and the high rate of sperm reappearance after vasovasostomy.…”

“…For instance, Silber [9] increased the conception rate to 74% in this way. (3) Another hypoth esis was that the destruction of the nerve sup ply to the vas deferens during vasectomy caused the low pregnancy rate after vasova sostomy [10,11].…”

Human Vasal Changes after Vasectomy: In vitro Studies

“…Activation of these sympathetic nerve fibers may induce vasal contraction and expulsion of sperm at the time of ejaculation [19], Local injury of the nerve fibers supplying the vas and epididymis during vasectomy could lead to inadequate contraction of the excurrent duct system and ultimately impair sperm function [20]. The regeneration of these nerves may account for the slow recovery of the ejaculate [21]. Some investigators have suggested that preserving the neural sheath of the vas may play an important role in preserving its contractile func tion [22], The alpha-adrenergic component of the vas innervation plays a major role in stimulating muscle con tractions, and alpha-blockers have been shown to attenu ate nerve-induced contractile response [19].…”

Structure and autonomic innervation of the human vas deferens: A review

“…VAS DEFERENS The effects of vasectomy on the innervation of the vas deferens are more easily studied in laboratory animals and several reports have appeared in the literature on this subject (Alexander et al, 1979;Carey et al, 1988;Flickinger, 1975;Hamidinia et al, 1980). One study in the human (Dixon et al, 1987) used neurohistochemical and fine structural techniques to examine samples of the vas deferens obtained from the distal (testicular) and proximal (urethral) segments at the time of vasovasostomy.…”