Human vasal changes after vasectomy: in vitro studies.

Abstract

Failure to impregnate, after successful vasovasostomy, has been attributed to immunologic, testicular, and epididymal factors. To study the effect of vasectomy on human vas innervation and vesicoelastic properties. Vas rings were obtained from 8 healthy males during vasectomy as controls and compared to those of 3 vasovasostomy patients. The active and passive properties were determined and the cumulative blocking effects of phenoxybenzamine, propranolol, atropine and tetrodotoxin were studied. There was significantly higher rigidity in the vasovasostomy group as compared to the control group but there were similar active forces between the two groups up to 100-120% of stretch. In the control group, phenoxybenzamine blocked 33.3%, propranolol blocked 15.8%, and atropine blocked 36.5% but tetrodotoxin had no further effect. In the vasovasostomy group, phenoxybenzamine blocked 33.3% (similar to control), propranolol blocked 2%, atropine blocked 11.7% and tetrodotoxin blocked 37.1%. In vasovasostomy group there was increased rigidity without reduction of the active force. There were also decreased cholinergic and possible existence of nonadrenergic noncholinergic neurotransmitters.