The lymphatic drainage of the epididymis and of the ductus deferens of the rat, with reference to the immune response to vasectomy.

The lymphatic drainage of the testis, epididymis and ductus deferens was determined in unoperated and in unilaterally vasectomised Albino Swiss rats. In the vasectomised animals, the lymphatic drainage of epididymal and vasal sperm granulomas was also investigated. The normal epididymis, and sperm granulomas which develop in it after vasectomy, drain to the regional testicular lymph node via the inferior epididymal trunk; vasectomy does not interfere with this route. There is a lymphatic watershed within the middle one third of the scrotal ductus deferens; lymph may drain caudally, to enter the inferior epididymal trunk and/or rostrally to the iliac node. Lymphatics draining granulomas at the vasectomy site, may, therefore, be interrupted by vasectomy. This would contribute to, but does not fully explain, the variable immune response of the regional testicular node following vasectomy.