Gonadal effects of vasectomy and vasoligation.

During a 28-week study, vasectomy and vasoligation of immature male Wistar rats revealed that there was a significant decrease in urinary 17-ketosteroid in the vasectomized group at week 15; at week 28 there were significant decreases in the weights of the testes of the test groups, as compared to those receiving sham operations, with maximum alterations in the vasectomized rats. Small, soft discolored testes with cysts in the cauda epididymis and vas deferens regions occurred frequently in the test groups. The output of 17-ketosteroid in the urine and the findings in the testes indicate significant alterations in the morphology and function of the testes and suggest the need for caution and extensive investigations in man before recommending vasectomy as a simple, innocuous, "physiologic" means to ensure conception control.