A 58-year-old man with T3N1M0 rectal carcinoma (mid-rectum, 8 cm from anal verge) undergoes pre-operative long-course chemoradiotherapy followed by low anterior resection with total mesorectal excision (TME). The key oncological principle behind TME is:
- A Achieving a 5 cm distal bowel margin to reduce local recurrence
- B Sharp dissection along the mesorectal fascial plane to remove an intact mesorectal envelope containing lymphovascular structures ✓
- C Removing the entire sigmoid colon to ensure adequate proximal margin
- D Dividing the inferior mesenteric artery at its aortic origin to harvest central nodes
Correct answer: B. Sharp dissection along the mesorectal fascial plane to remove an intact mesorectal envelope containing lymphovascular structures
Explanation
Total mesorectal excision (TME), pioneered by Heald, involves sharp dissection in the embryological avascular plane between the visceral and parietal pelvic fascia, removing the rectum with an intact mesorectal envelope containing perirectal fat, lymphatics, and vessels. This reduces local recurrence from ~25% to <5%. A 1 cm distal margin is adequate for mid/low rectal cancers. Sigmoid resection extent depends on vessel ligation, not oncology of the rectum per se.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.