Techniques for restoring bowel continuity and function after rectal cancer surgery.

摘要

A very low local recurrence rate of 3%-6% (associated with improved 5 year survival) is possible when proper oncological surgery is performed of mid and distal rectal adenocarcinoma. Restoration of bowel continuity is possible in most cases, without compromise of cancer clearance. Re-anastomosis can be performed with stapled, transabdominal hand-sewn or coloanal pull-through techniques. However after a direct (straight) anastomosis of the colon to the distal rectum/anus, up to 33% of patients have 3 or more bowel movements/d; some can be troubled with up to 14 stools a day. Construction of a 6-cm colonic J-pouch is likely to cause some reversed peristalsis which improves postoperative bowel frequency without causing neo-rectum evacuation problems. Colonic J-pouch-anal anastomosis patients have a median of 3 bowel movements a day compared with a median of 6 a day for straight anastomoses, at 1 year after surgery. In the longer term, bowel adaptation may enable the function after a straight anastomosis to approximate that of a colonic J-pouch-anal anastomosis. This probably depends in the former, upon whether the more rigid sigmoid colon or more distensible descending colon is used. An additional advantage of the colonic J-pouch-anal anastomosis is the lower risk of anastomotic complications. A more vascularized side-to-end (colonic J-pouch-anal) anastomosis is likely to heal better than an end-to-end (straight) anastomosis. Where the pelvis is too narrow for a bulky colonic J-pouch anal anastomosis, a coloplasty-anal-anastomosis is an option. The latter results in postoperative bowel function comparable with the colonic J-pouch. However, the risk of anastomotic complications is higher possibly related to its end-to-end anastomotic configuration. Laparoscopic techniques for accomplishing all the above are being proven to be effective. Restorative surgery for rectal cancer can be safely and effectively performed with methods to improve bowel function very acceptably; the future advances are likely in laparoscopy.