Sigmoidectomy Procedure Of The Human Colon

Description

Sigmoid colon occupies the left lower quadrant as an S-shaped segment bridging the descending colon superiorly to the rectum inferiorly, and this illustration centers on its surgical excision in a sigmoidectomy. The bowel is presented with the adjacent mesocolon (mesosigmoid) opened to expose the vascular pedicle, where sigmoid branches of the inferior mesenteric artery and accompanying veins course medially toward the marginal artery along the colonic border. Proximally, the distal descending colon is the upstream resection margin, while distally the upper rectum or rectosigmoid junction forms the downstream margin, orienting the viewer to the planned end-to-end anastomosis. Key pelvic relationships are maintained, with the left ureter and gonadal vessels expected posterior and lateral to the mesosigmoid and the hypogastric nerves positioned presacrally. Orientation matters. Sigmoidectomy is commonly performed for complicated diverticulitis, obstructing or bleeding sigmoid carcinoma, and selected cases of volvulus, so appreciating where the mesenteric vessels tether the segment explains both the operative dissection planes and ischemic risk. The fixed perspective emphasizes the continuity of the marginal artery and the location of the rectosigmoid junction, two landmarks that influence the choice between high versus low ligation of the inferior mesenteric artery and the length of mobilization needed for a tension-free anastomosis. Attention to the posterior mesocolic plane also aligns with the clinical priority of avoiding ureteral injury and preserving pelvic autonomic nerves to reduce postoperative urinary and sexual dysfunction. Use this illustration in general surgery and gastrointestinal anatomy teaching, colorectal fellowship slide decks, and medical publishing layouts covering large intestine resection, anastomotic technique, and complications such as leak, bleeding, and stricture. It also fits patient-facing informed consent materials when paired with simplified labels for bowel, blood supply, and resection margins. Anatomical accuracy verified by SciePro's Medical Advisory Board.