Factors that influence fertility after vasovasostomy in rats

Objective To determine if fertility after vasovasostomy of immunologically responsive Lewis rats differs from that of the less responsive Sprague-Dawley strain and to relate fertility to antisperm antibodies, fluid flow in the vas deferens, and testicular structure. Design Male rats received: (1) bilateral vasectomies; (2) vasectomies followed 3months later by vasovasostomy; or (3) sham operations. Setting Research laboratory. Main Outcome Measures Fertility was assessed by caging males with three females for 2weeks and subsequently counting implantation sites. Antisperm antibodies were measured with an enzyme-linked immunosorbent assay, fluid flow through vas deferens segments was tested in vitro, and testicular structure was studied microscopically. Results Nearly all vasovasostomized Lewis rats were infertile (33 of 34), whereas 62% (18 of 29) Sprague-Dawley rats were fertile after vasovasostomy ( P Conclusions Genetic differences affect fertility after vasovasostomy. Fertility after vasovasostomy is also influenced in a multifactorial manner by the immune response, mechanical elements, and structural changes in the reproductive tract.