Influence of vas deferens mobilization on rat fertility: implications regarding orchiopexy.

Children who undergo bilateral orchiopexy often have oligospermia or azoospermia in adulthood. This subfertility generally has been attributed to histological alterations in the cryptorchid testis. However, the possibility that an iatrogenic factor, such as mobilization of the vas deferens during orchiopexy, may have an adverse effect on fertility has not been studied. Six groups of mature Sprague-Dawley rats underwent right orchiectomy and the following procedures on the left side: group 1--sham operation, group 2--2 cm. of vas mobilized, group 3--4 cm. of vas mobilized, group 4--2 cm. of vas mobilized and deferential artery stripped off of vas, group 5--4 cm. of vas mobilized and deferential artery stripped off of vas and group 6--vasectomy. Each rat was then housed with 2 female rats for 24 days. Mobilization of the vas with disruption of the mesentery resulted in slight but statistically insignificant reduction in fertility. However, when the deferential artery was dissected off the vas, there was a marked reduction in fertility and fecundity. Histologically the vasa were normal without evidence of ischemic necrosis. The testes in groups 2 to 5 showed variable depletion of germ cells with shedding of germinal epithelium, and the testes and epididymides in group 5 were similar to the changes seen in vasectomized rats (group 6). No testes were necrotic. These data suggest that extensive mobilization of the vas causes subfertility in this animal model and may be secondary to a functional obstruction resulting from vas denervation. Whether a similar effect occurs during orchiopexy in humans deserves study.