Intravas device studies in rabbits: II. Effects on sperm output, fertility and histology of the reproductive tract

Abstract

Solid (rod) and open (tube) prototype gold-platinum intravas device housings of three different surface designs were surgically inserted into the vasa deferentia of rabbits to test the feasibility of controlling male fertility. The devices were inserted through a short longitudinal slit in each vas deferens, secured with 4-0 silk suture and remained in situ for various periods ranging from 56–426 days. The solid devices completely inhibited the fertility of 6 rabbits in 20 of 21 matings. The fertile mating resulted after the loss of a device in one animal. In contrast, 7 of 9 rabbits receiving identical, but open (i.d. 0.8 mm), devices were fertile in numerous matings. Reduced sperm numbers or sperm-free ejaculates were usually obtained for 2–3 weeks after surgery, but returned to normal following this period. However, sperm blockage due to connective tissue infiltration and eventual encapsulation of the open devices was subsequently observed in about 50% of the animals. Histological changes of the vas deferens at the sites of some of the devices included occasional sperm granulomas, mild focal submucosal edema, mucosal erosion and mild mucosal hyperplasia due to fibroblastic proliferation.