Sperm granulomas: An adverse effect of vasectomy

Spermatic granulomas were always present 6 mth after prepubertal or postpubertal vasectomy in the rat. Neither sperm leakage at the operation nor suture material is a necessary predisposing factor in granuloma formation. These granulomas contain massive accumulations of sperm (0.8 to 1.8 billion) which may account for a considerable portion of the testicular output of sperm during this 6 mth period. This might suggest minimal reabsorption of sperm in the epididymis following vasectomy. Although granulomas were most frequently found at the site of ligation, individual granulomas were observed proximally in the vas deferens and epididymis. A spectrum of granulomatous inflammation was observed in these lesions, including the ultimate reabsorption of the sperm by histiocytic phagocytes. These lesions are discussed in relation to immunologic considerations.