Background: Vasectomy is one of the most effective tools of population control. Controversies are arisen with respect to the effects of vasectomy on testis and the process of spermatogenesis, thus the present study was carried out to determine the effects of closed-end and open-end vasectomies on rat’s testis in Kashan University in 2000.

Materials and methods: For this experimental study, 20 Sprague Dawely rats were randomly selected. They were 8-12 weeks old and assigned in two groups of closed-end and open-end vasectomies. For the first group (closed-end) right vas deferens underwent closed-end operation and vas deferens of the left side underwent Sham operation, however for the other group (open-end) right and left vas deferens underwent open-end and Sham operations, respectively. 4 months later, their testes were removed and their weight, volume and macroscopic appearance were determined. Then, microscopic changes including histologic changes, seminoferous ducts, interstitial tissue, number of spermatogonia, number and type of spermatocytes, etc were all recorded. T-test was used for data analysis.

Results : Histologic studies revealed that testicular tissue was normal in control group but have changes in the case group. In injured ducts detachment of immature cells from epithelium, epithelial vacuolization, thickening and folding of periductal membrane, and removal of germ cells were prominent changes. Quantitative evaluation of normal ducts revealed that there was significant differences between groups regarding: number of spermatogonia, spermatocyte, round spermatid, long spermatid, the proportion of long spermatid to sertoli, ductal diameter, and volume and weight of testis.

Conclusion : There was no significant difference between the closed- and open-end vasectomies, however both affect the testicular tissue. Effects of increased hydrostatic pressure were less prominent in closed-end technique. Further studies with special attention on increased antisperm antibody , and seminoferous ductal structure wit0.h ultrastructure and immunochemistry are strongly suggested.