Sterilization by vas occlusion without transection does not reduce postvasectomy sperm-agglutinating antibodies in serum. A randomized trial of vas occlusion versus vasectomy.

The influence of transection of the vasa on the increase in sperm-agglutinating activity in serum after vasectomy was investigated in a prospective randomized study. Sixty-eight males requesting vasectomy were allocated to either of two groups: vas occlusion by tantalum clips without transection of the vasa, or conventional vasectomy by transection and ligation. Sperm-agglutinating antibodies were determined by a micro-agglutination test before and 6 months after vasectomy or vas occlusion. A significant increase in sperm-agglutinating activity in serum after sterilization was found in both groups, but there was no intergroup difference.