Surgery for rectal cancer
Discuss rectal surgery for cancer?
- The type of surgery depends on the location of the rectal cancer.
- Dentate line is the landmark where the squamous mucosa of the anus transitions to the columnar mucosa of the rectum. The dentate line is located in the middle of the anorectal ring, which comprise both the external and internal sphincter. These muscles provide a high-pressure zone (responsible for continence) extending 1-3 cms proximal to the dentate line.
- For a sphincter saving operation, the rectal cancer should be located high above the top of the anorectal ring to allow for an adequate distal margin.
Options for curative rectal cancer surgery:
- Local excision- for superficially invasive small cancers
- Low anterior resection (LAR or sphincter-saving surgery) – cancers of the upper and middle third can be treated by LAR with preservation of anal sphincter. Resection and colo-anal anastomosis is feasible as long as a distal resection margin of 2 cms can be obtained.
- Abdominal perineal resection (APR) — it involves removal of the anus, rectum and distal sigmoid colon along with regional lymph nodes. The sigmoid colon is brought out permanently as a colostomy. APR requires incisions in both the abdomen and perineum.
