Sphincter-preserving surgery for rectal cancer: when a permanent colostomy is avoided

One of the biggest concerns for patients with rectal cancer is a permanent colostomy. Modern sphincter-preserving surgery aims precisely to remove the tumour with oncological safety while preserving the sphincter and normal bowel function where this is feasible.

What “sphincter-preserving” surgery means

Sphincter-preserving surgery removes the rectal cancer without sacrificing the anal sphincter, so the patient keeps control of bowel movements. By contrast, abdominoperineal resection (the Miles procedure) requires a permanent colostomy and is reserved for very low tumours that invade the sphincter.

The role of TME (total mesorectal excision)

The cornerstone of rectal surgery is total mesorectal excision (TME): removal of the rectum together with its surrounding fatty envelope and lymph nodes as one intact “package”. A proper TME dramatically reduces local recurrence and is critical to the oncological outcome.

Low anterior resection and anastomosis

For most mid and upper rectal tumours a low anterior resection is performed: the segment with the tumour is removed and the bowel is reconnected (anastomosis), preserving the natural route. A temporary protective ileostomy is often created to protect the anastomosis and is reversed at a second stage.

Robotic precision in the narrow pelvis

Robotic low anterior resection offers a stable 3D camera, wristed instruments and excellent visibility in the narrow pelvis (especially in men). This helps precise dissection along the correct anatomical planes, preservation of the pelvic nerves (bladder and sexual function) and sphincter preservation in low tumours.

When the sphincter is preserved — and when not

Sphincter preservation depends mainly on the distance of the tumour from the sphincter, on invasion, and on the response to neoadjuvant (preoperative) chemoradiotherapy, which can shrink the tumour and make a sphincter-preserving operation feasible. When the tumour directly invades the sphincter, a permanent colostomy may be unavoidable for oncological reasons.

The strategy is decided by a multidisciplinary tumour board and individualised. More on the page for rectal cancer.