Lateral ligament: Its anatomy and clinical importance

Since Miles proposed abdominoperineal excision as a radical surgery for rec tal cancer in 1908, surgeons have recognized the lateral ligament in the pa rarectal space of their patients and attached clinical importance to it, al though anatomists did not describe any such configuration in cadavers. By a nalyzing an experience of 421 lower rectal cancer cases at the Cancer Insti tute Hospital in Tokyo, discussion of the lateral ligament was focused on i ts relationship to the fascial arrangements in the pelvis, the pelvic auton omic nervous system, and the lymphatic drainage of the rectum. The lateral ligament is not an anatomical term, but a clinical or surgical one. It exis ts in a living pelvis as a condensation of connective tissue around the mid dle rectal artery and is divided into two segments by the inferior hypogast ric nerve plexus inside it and the visceral endopelvic fascia around it. Th e lateral ligament is a pathway of blood vessels and nerve fibers toward th e rectum and lymphatic vessels from the lower rectum toward the iliac lymph nodes. Therefore, the lateral ligament plays a critical role in surgery fo r lower rectal cancer in two respects: the anatomic extent of resection for curing rectal cancer, and the preservation of sexual function. (C) 2000 Wi ley-Liss, Inc.