Surgical induction of varicocele in the rabbit.

Surgically induced varicoceles were created in male rabbits of proven fertility by partially occluding the left lumbotesticular trunk, which receives the left testicular vein before draining into the left renal vein. Semen was collected every 2 weeks following surgery and left testicular biopsy was performed at 2, 4, 8 and 13 postoperative weeks. Tissue was processed for light and electron microscopy. Animals were sacrificed at 20 postoperative weeks. Left testicular vein dilatation was observed at autopsy (20 weeks postoperative), as were changes in semen quality. These included an increase in the number of round germ cells and abnormal spermatozoa, as well as a decrease in sperm numeric density and motility. Seminiferous tubule pathology was variable and germ cell sloughing was observed as soon as 8 weeks following surgery. Spermatids were maloriented relative to Sertoli cells and Sertoli-germ cell junctional complexes were structurally abnormal. Results indicate that surgical induction of varicocele in the rabbit leads to altered spermatogenic function and decreased semen quality similar to that described in humans. Epithelial disruption appears to be a phenomenon of the adluminal testicular compartment and apical Sertoli cell cytoplasmic degeneration may account for the poor semen quality associated with varicocele.