Experimental vasectomy and testicular structure.

We have performed an experimental study on rats and dogs to evaluate the long term effects (from 1 to 12 months) of vasectomy on the structure of the testis. From four months after vasectomy onwards, the specimens showed very important changes in the seminiferous epithelium and Sertoli cells, with an obvious thickening of the basement membrane that supports the epithelium. The deterioration depended on the time passed and, over six months after vasectomy, the alterations were very clear and the seminiferous tubules became atrophic and shrunk, sometimes without any remains of seminiferous epithelium and with an important hypertrophy of the interlobular interstitial tissue, although we did not see an increase in the number of Leydig cells. Alterations due to vasectomy depend on the animal species, the peculiarities of techniques and, of course, the time passed after surgery.