High and low inferior mesenteric artery ligation

The inferior mesenteric artery supplies the descending colon, sigmoid colon, and rectum, and the competent surgeon must decide whether a high or low ligation should be performed before proceeding with its ligation. The decision requires technical, anatomic, and oncologic reasoning to inform the surgeon and will depend on the location and extent of disease that requires resection. Resection for colorectal cancer typically dictates the more extensive high ligation, while surgery for benign conditions typically permits a low ligation. There are risks inherent to a high ligation of the inferior mesenteric artery, including injury to autonomic nerves with resultant genitourinary and anorectal dysfunction, inadvertent ureter injury, and decreased blood flow leading to anastomotic dehiscence. However, benefits of a high ligation include increased mobilization for anastomosis creation and a greater yield of lymph nodes within the larger resection. A low ligation occurs distal to the branching of the left colic artery and has the benefit of retaining a greater blood supply to the remaining colon. However, a low ligation makes the anastomosis from the descending colon to the remnant rectum or anal canal more difficult. Undue tension placed upon the anastomosis from a low ligation will increase the risk of anastomotic leak and failure. In single-incision laparoscopic colorectal surgery (SILS), as in traditional open or multiple port laparoscopic colorectal surgery, the completion of high or low ligation of the inferior mesenteric artery is based on multiple factors. The operative techniques, and the basis for choosing these techniques, are reviewed here.