Intersphincteric resection, open, with transanal colon pull-through and transverse coloplasty pouch

Longitudinal laparotomy.

Free the left colon up to the middle of the transverse colon with release of the splenic flexure. Identify and dissect the inferior mesenteric vein, ligament of Treitz and the arterial blood supply.

High ligation and suture ligation of the inferior mesenteric vein at the inferior aspect of the pancreas.

After suture ligation of the inferior mesenteric artery close to its origin, divide the artery while sparing the superior hypogastric plexus.

After instituting Trendelenburg position, open the peritoneum at the base of the mesosigmoid and mesorectum on both sides from anteriorly to the promontory down to the pouch of Douglas, and then open the "holy plain" posterior to the mesorectum, respecting the layers and the hypogastric nerves.
Perform this dissection akin to total mesenteric excision.

After identification of the ureters continue the posterior dissection within the lateral layer. Stretching the mesorectal boundary facilitates layered dissection along the mesorectal fascial sheath. Dissect the mesorectum posteriad on the fascia of Waldeyer down to the pelvic floor.

Dissect both lateral ligaments and divide the ligament structures between the coccyx and rectum. Now incise the anterior peritoneal reflection between the bladder /uterus and rectum and dissect down to the Denonvilliers fascia. While staying within the correct layer carry the dissection down to the suprasphincteric/intersphincteric level. In men take particular care to respect the plexus of nerves and veins encasing the seminal vesicles. The inferior hypogastric plexus on the anterolateral pelvic floor must be spared.

Tip: In women, dissection takes place in the retrovaginal space. In anterior cancer, partial resection of the posterior vaginal wall may be required.

Now palpate the rectum to assess if the dissection has been carried down deeply enough and how it relates to the tumor.

Exposure of the puborectalis muscle will also allow assessment if the dissection has been carried down deeply enough.