Middle Rectal Artery, Anterior View

Description

Arising from the internal iliac artery, the middle rectal artery courses anteromedially within the male pelvis toward the lateral wall of the rectum, reaching it superior to the levator ani and pelvic diaphragm. The terminal descending colon and sigmoid colon continue inferiorly into the rectal ampulla, with haustra fading as the rectum begins. Red arterial branches track along the mesorectal plane while accompanying blue venous channels return toward the internal iliac venous system, and fine autonomic fibers follow the vessels along the pelvic splanchnic and hypogastric pathways. Color coding stays consistent. Middle rectal vessels matter because their size and presence vary, and they sit directly in the field of low anterior resection and total mesorectal excision for rectal cancer. When you mobilize the rectum off the pelvic sidewall, these branches can be a source of brisk bleeding or a landmark for the lateral ligaments of the rectum, and they also contribute to anastomotic perfusion alongside the superior rectal artery (from the inferior mesenteric artery) and inferior rectal branches (from the internal pudendal artery). Injury here also risks disrupting adjacent pelvic autonomic nerves, a mechanism behind postoperative urinary or sexual dysfunction. Ideal placement includes colorectal surgery atlases, pelvic anatomy modules in medical school or PA curricula, and teaching files that contrast hindgut vascular territories with autonomic innervation of the rectum and sigmoid colon. It also supports case-based discussions on rectal hemorrhage, anastomotic leak risk, and operative planes during TME. Anatomical accuracy verified by SciePro's Medical Advisory Board.