OR / Prep · Colorectal Surgery · laparoscopic
You’re scrubbing into
Low anterior resection with TME
Why are we operating?
Rectal cancer surgery is a dissection of one embryological package: the mesorectum comes out intact or the operation has failed, whatever the margins say.
Indication: Rectal cancer above the sphincters, usually after MDT-directed neoadjuvant therapy.
Read the imaging first
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Practice before you scrub
The margin that writes the plan
A 61-year-old with rectal bleeding; colonoscopy found a rectal tumour. Staging MRI of the pelvis. (Fictional educational case.)
- Rectal cancer is staged in millimetres: the tumour's distance from the mesorectal fascia decides whether surgery leads or follows radiotherapy.
- The same envelope logic is the operation: TME removes the rectum inside an intact mesorectal package, and the pathologist grades the surgery by its surface.
The operation in 4 steps
01Vascular control
The inferior mesenteric artery is divided near its origin and the inferior mesenteric vein near the pancreas; the splenic flexure is often mobilised.
Why: The high arterial tie harvests the nodal chain; the flexure comes down so the colon can reach the pelvis without tension. The hypogastric nerve plexus sits millimetres from the arterial origin and is swept away before the tie.
02Total mesorectal excision
The rectum and its mesorectum are dissected as one package in the areolar 'holy plane' between mesorectal fascia and pelvic sidewall, down to the pelvic floor.
Why: Rectal cancer deposits live in the mesorectal fat; the fascia around it is the oncological wrapping paper. Staying in the plane removes the cancer's whole territory and protects the nerves that live just outside it.
03Distal division
The rectum is divided below the tumour with a distal margin confirmed adequate, typically stapled deep in the pelvis.
Why: The distal margin is measured, not guessed, because centimetres decide whether the sphincters can be kept; the narrower pelvis makes this the operation's most awkward move.
04Anastomosis and defunctioning
Colorectal or coloanal anastomosis fashioned, air-leak tested, and usually covered by a temporary loop ileostomy.
Why: A low join leaks more often than any other in the abdomen; the ileostomy does not stop a leak, it turns a pelvic catastrophe into a contained problem while the join heals.
Anatomy you need
The rectum's course into the pelvis; the mesorectal plane this operation is named for wraps what you see.
What can go wrong
Anastomotic leak
Day 3–7: tachycardia, fever, abdominal pain, ileus that fails to resolve, or subtle deterioration that 'doesn't add up'.
Postoperative bleeding
Tachycardia first, hypotension late; falling urine output; a distending abdomen or rising drain output.
Postoperative ileus
Distension, absent flatus, intolerance of diet, and quiet bowel sounds in the days after abdominal surgery.
Venous thromboembolism
Unilateral leg swelling, or sudden dyspnoea, pleuritic pain, tachycardia, sometimes the only sign is unexplained hypoxia.
Watch it done
Low anterior resection: surgical management of rectal cancer
The University of Toronto atlas explaining the resection, the mesorectal plane and the anastomosis.
Source: TVASurg, Toronto Video Atlas of Surgery · Watch on YouTube
Conceptual teaching for learners preparing to observe and assist under supervision, not operative instructions. Five minutes from now you should know why this operation exists, what its shape is, and which structures it is designed not to injure.