For patients with FAP, MAP or SPS, surgery is often advised to prevent bowel cancer
For patients with familial adenomatous polyposis (FAP), MYH associated polyposis (MAP) and sometimes for those with serrated polyposis syndrome (SPS), surgery is advised to prevent bowel cancer. This is usually offered when the number of polyps in the large bowel exceeds 100 and/or the polyps are growing above 1cm in size. For classical FAP this may be offered at the ages of 16-18 (quite often we perform surgery in the summer break between GCSE’s and A-Levels), for less severe forms of FAP (so called attenuated FAP), MAP and SPS, this may be offered at a later age if we become concerned about increasing polyp count.
Types of operations used
Colectomy with ileo rectal anastamosis
This operation involves removing the colon (large bowel). The end of the small bowel (ileum) is then joined (anastamosed) to the top of the rectum. This is why it is called an ileo rectal anastamosis or IRA for short. This surgery leaves the rectum in situ. The rectum is part of the large bowel and polyps will continue to grow in this area. For this reason, patients are carefully selected for this operation and must agree to undergo 6 monthly endoscopic surveillance of the rectum following surgery. There is a chance that patients will grow too many rectal polyps in the future and need to undergo further surgery. In order to be suitable for this surgery, patients should have less than 500 colonic polyps and less than 20 rectal polyps at the time of surgery. They should not have a severe type of FAP (such as the 1309 mutation). Patients are carefully counselled with regard to the above issues. The benefits of having this surgery is that patients’ bowel function is usually very good following the operation (patients may open their bowels, on average, 2-4 times per day). In addition, female fertility is not usually affected.
This operation involves removing the colon and rectum. An artificial rectum, called a pouch, is made out of the lower end of the small intestine (ileum). The pouch is then joined to the anus so bowel actions can be controlled in the same way. The pouch stores the faeces until the person goes to the lavatory in the usual way. This operation is carried out in two stages. The first stage is where the colon and rectum is removed and the pouch is made and joined to the anus. The operation is quite complicated and it is important to allow the new pouch time to “rest” while it heals. This is done by creating a temporary ileostomy above the pouch. The stools will be collected in a bag, which is worn outside the body, on the abdomen (tummy). The bag will need emptying at certain times. After approximately 3 months, the ileostomy is closed by a second operation (stage 2) so that stools are again passed from the anus. Patients who are undergoing this type of surgery will be seen by one of the pouch nurses prior to the procedure and counselled regarding what to expect post surgery. Having a pouch means that usually people will open their bowels more frequently (on average 6-8 times per day) and sometimes at night. Following surgery, the pouch must be checked endoscopically on an annual basis to ensure no polyps are growing in the area. Again, patients must be carefully selected for this surgery. It is more complex surgery than the IRA and female fertility can be reduced following the operation. For this reason, it is usually only carried out for patients with a more severe form of FAP or MAP, when a large number of large bowel polyps are seen at diagnosis.
Total colectomy with end ileostomy
This operation involves removing the entire large bowel, rectum and anus (bottom). The anus is then sewn up and a stoma is formed from the end of the small bowel. This stoma is called a permanent ileostomy or end ileostomy. It cannot be reversed in the future as everything below the level of the stoma has now been removed. This type of surgery is only performed in certain circumstances (e.g. a patient is referred with a low rectal cancer) and is not first-line surgery for polyposis patients.
Surgery for other Syndromes (Peutz-Jeghers and Juvenile Polyposis)
The aim in Peutz-Jeghers Syndrome is to remove polyps in the small intestine before they become large and cause problems, such as intussusception. Usually this can be manged endoscopically with the use of a special endoscope called a double balloon endoscope (DBE). Surgery for Peutz-Jeghers is sometimes required, however, if the polyps are too large, there are too many of them or if a patient has scar tissue (adhesions) from previous abdominal surgery. A joint endoscopic and surgical procedure called a PJ laparotomy with on-table enteroscopy (clearance of small bowel polyps) is the type of operation used in this scenario.
In Juvenile Polyposis, surgery is occasionally used. The stomach and large bowel are the two areas most commonly affected by large numbers of polyps and sometimes the surgeon will recommend a gastrectomy (removal of stomach) or partial gastrectomy or colectomy (as described above).
In both these conditions, should surgery be needed, your surgeon and specialist nurse will discuss your options in more detail.