History and Objectives: vasectomy is one of the prevalent method approved by the Ministry of Health and Medical Education for prevention of male reproductive competency. Due to discrepancies in the reported cases of the effect of vasectomy on the testicular tissue of human and animal models, in order to determine the long term affected of vasectomy on the general appearance and histology of testicular tissue, the present study was carried out in Tarbiat Modares university in 1995.

Materials and Methods: An experimental study on 14 Wistar rats was performed. They were randomly divided equally into 2 vasectomy and shame operated groups: A bilateral surgery was performed on all rats. Changes in the testicular tissue were assessed by taking histologic samples (With hematoxillin-eosin, PAS and trichrome mission staining) 6 months after the surgery. Weight and volume of testis, seminiferous tubule diameter, epithelium thickness of seminiferous tubule, testicular volume percentage and number of epithelial germinal sertoli cell of seminiferous tubule were recorded. Data gathered from 2 groups was compared and statistical analysis was done.

Results: vasectomy induces changes in increased folding of membrane of seminiferous tubule, vacuolization of epithelium seminiferous tubule and desquamation of immature germ cells, in vasectomized group. Comparison of the changes of variables under investigation in 2 groups indicates that there is a significant difference between the 2 groups. Testicular weight (1.2±0.2 in vasectomized group compared to 1.5±0.2 g in control group), testicular volume (1.1±0.2 cm³ compared to 1.4±0.2 cm³) (P<0.0005), seminiferous tubular thickness 225±53 micron compared to 78±15.1 micron) (P<0.0001) showed significant reduction. In addition, testicular volume percentage and number of germ cells in 2 groups showed significant difference (P<0.0001). However, number of sertoli cells did not changed significantly.

Conclusion: Vasectomy induces significant changes in the rat testicular tissue which further study is required to elucidate the underlying mechanism and extrapolation of the results to humans.