Because of the very high likelihood of colorectal cancer in children diagnosed with familial adenomatous polyposis, surgery to remove the colon should be performed as soon as it can be safely conducted.
Surgery in children with GI polyposis includes prophylactic protocolectomy with ileorectal anastomosis or proctocolectomy with ileal pouch-anal anastomosis.
Proctocolectomy, also called a total colectomy, involves removal of the entire colon. This is a common treatment for polyposis because of the cancer risk associated with the disease.
Prophylactic proctocolectomy is surgery performed as a preventive measure to protect against the development of cancer in the colon. It is most often the preferred surgical option in patients with familial adenomatous polyposis; however, given the risk of recurrent polyps in the anal canal and ileal pouch and the increased long-term complications of proctocolectomy in younger children, ileal pouch-anal anastomosis may provide a safer alternative in younger children.
While patients with juvenile polyposis have an increased risk of cancer, colorectal cancer does not always occur. Therefore, the colon can be preserved for as long as endoscopic removal of all detectable polyps can be assured. In addition, although patients with Peutz-Jeghers are clearly at risk for cancer, they are not usually referred for prophylactic colectomy if their polyps remain manageable with endoscopy and polypectomy alone.
How the surgery is performed
In all colectomies, the bowel is either reconnected afterward (which is called an anastomosis) or the surgeon creates an ostomy, an opening of the bowel on the abdominal wall, to allow the contents of the bowel to exit from the body Colectomies can be performed through a single long incision in the abdomen (an open colectomy), or several small incisions (a laparoscopic colectomy). If the surgery is performed laparoscopically, the surgeon makes a small incision under the belly button, and two other very small incisions near the diseased section of the colon. The surgeon then maneuvers small surgical instruments through these incisions using a lighted scope. The abdomen is inflated with carbon dioxide to give the surgeon a better view. Both types of surgery generally take from one to four hours.
In some situations, the patient will likely require an ostomy to temporarily or permanently redirect body waste through an opening created in the patient's abdomen where it is drained from the body into an attached bag. There are two types of ostomy:
- Ileostomy: This operation creates an opening to the small intestine (ileum) through the abdomen. Intestinal contents drain from this location and are similar in consistency as toothpaste.
- Colostomy: This operation establishes an artificial outlet for the large intestine (colon). Waste draining from this opening will be soft or more formed depending on the part of the colon involved.
Ileal pouch-anal anastomosis
FAP sometimes requires removal of the entire colon and rectum called an ileal pouch-anal anastomosis. In this procedure, the surgeon usually constructs a pouch from the end of the small intestine that attaches directly to the anus. Waste is then expelled normally, although bowel movements frequently are watery.
In some children with FAP, depending on their age, size, type of gene mutation, behavior of the disease in the family and number of polyps the best procedure is an ileo-rectal anastomosis. This procedure leaves part of the large intestine in place and usually results in less watery, and less frequent stooling.