Vas deferens, a site of male contraception: an overview

The vas deferens is a site which can be exploited for male contraception wi thout undue side effects. The only effective technique available for male c ontraception is vasectomy, being practiced world wide, despite that it is a permanent surgical procedure and its successful reversal is not assured. A lthough no-scalpel vasectomy minimizes surgical procedures, the fate of its reversal is akin to that of vasectomy. Several occlusive and non-occlusive vasal procedures which claim to be reversible without surgical interventio n, possess more disadvantages than advantages. Vas occlusion with plug, 'Sh ug' or medical grade silicone rubber, although claimed to produce reversibl e azoospermia without affecting spermatogenesis, requires skilled microsurg ery for their implantation and later removal. RISUG(R), a non-sclerotic pol ymer styrene maleic anhydride (SMA), could be more advantageous than vasect omy and other vas occlusive procedures in that it could be a totally non-in vasive procedure by "no-scalpel injection" and "non-invasive reversal". It is claimed to offer long-term contraception without adverse side effects an d also to be possible as a male spacing method by repeated vas occlusion an d non-invasive reversal. The drug is currently under multicentre Phase m cl inical trial.