Objectives. Although extensive research has been conducted on the normal anatomy and physiology of the epididymis, the effects of ischemia on the organ have not been primarily investigated. The aim of the present study was to investigate the macroscopic and microscopic effects of prolonged ischemia on the epididymis and the factors that may contribute to its resistance to ischemia.

Methods. Six groups of male Sprague-Dawley rats (6 rats/group) were studied. Groups 1, 2, and 3 underwent a sham operation of 4, 8, and 12 hours, respectively, and groups 4, 5, and 6 underwent 4, 8, and 12 hours of ischemia, respectively. The ipsilateral testes and epididymides were monitored throughout the experiment. At the conclusion of the experiment, bilateral orchiectomy was performed, and structures were histologically evaluated.

Results. There were no abnormal macroscopic findings of the bilateral epididymides of groups 1, 2, and 3 or of the contralateral, control epididymides of groups 4, 5, and 6. Macroscopically, there was a direct correlation between the length of ischemia and the degree of hemorrhagic discoloration of the proximal caput. The degree of hemorrhagic infiltration noted microscopically was consistent with the macroscopic observations. The epithelia of the ischemic epididymides remained intact with numerous microvilli.

Conclusions. The results of this study suggest that the epithelium of the epididymis is relatively resistant to ischemic damage compared with the gonad during testicular ischemia.