Middle Rectal Artery, Lateral View

Description

Running along the lateral pelvic wall, the internal iliac artery gives rise to the middle rectal artery as it courses anteromedially toward the rectum in an adult male. Nearby branches of the internal iliac system, including the inferior vesical and internal pudendal arteries, sit anterior and inferior in the expected relationship, while venous counterparts parallel the arterial trunks. Portions of the distal descending colon and sigmoid colon appear superior and lateral to the rectum, with epiploic appendages dotting the serosal surface and sigmoid vessels tracking within the sigmoid mesocolon. Lateral visualization of the middle rectal artery matters because its presence and caliber vary, yet it can be the dominant arterial supply to the mid-rectum and a meaningful contributor to collateral flow between the inferior mesenteric artery (via the superior rectal artery) and the internal iliac system. Bleeding during low anterior resection or total mesorectal excision often comes from lateral rectal pedicles, and the middle rectal artery is the named target when you ligate those pedicles close to the rectal wall to protect pelvic autonomic nerves. A small vessel, but a frequent surprise. Educators can place this plate directly into pelvic anatomy teaching on internal iliac branches, rectal vascular supply, and portosystemic anastomoses (superior rectal to middle and inferior rectal venous pathways) in colorectal surgery and gastroenterology modules. It also fits operative atlases and journal figures discussing rectal cancer resection planes, pelvic hemorrhage control, or selective internal iliac embolization planning where variant middle rectal anatomy changes the risk profile. Anatomical accuracy verified by SciePro's Medical Advisory Board.