Crohn's Disease Surgery - Perianal Surgeries

Unlike the surgery for treatment of Crohn's disease involving the intestine, surgery for the complications of Crohn's disease in the area of the anus (perianal disease) does not usually involve removing any segments of bowel.

 

Most operations are performed to reduce the symptoms of the perianal disease — most often pain and drainage of pus or stool — when the symptoms have not responded to other measures, such as sitz baths, antibiotics, immunosuppressants, and infliximab or when an acute problem, such as an abscess, has occurred.

 

 

Once the surgeon has adequately mapped out the extent of abscesses or fistulas, a procedure is chosen to reduce or eliminate the patient's symptoms. In some cases, this may involve cutting open the skin near the anus in order to allow an abscess to drain (incision and drainage).

 

 

In other cases, where there is a single fistula that does not cut across the anal sphincter, the surgeon may open up the fistula with an incision along its length (fistulotomy). This, in turn, allows the fistula to heal in, thereby eliminating the tract.

 

 

Where there are multiple fistulas or when the fistula crosses the anal sphincter, this type of fistulotomy is not possible because of the likelihood of causing damage to the sphincter, which would result in problems with loss of control of the bowels (incontinence).

 

Instead, the surgeon may pass a string, thread, or thin plastic band through the outside opening of the fistula on the skin around the anus, along the fistula tract as it passes under the skin and toward the anus or rectum, through the internal opening of the fistula inside the anus or rectum, and back out through the anal canal. The two ends of the string are tied together, effectively creating a loop through the fistula and the anus. This string or tube, also known as a seton, keeps the fistula open and allows it to drain in a controlled way.

 

This result would seem to be the opposite of one of the objectives of treating perianal disease — that is, reducing drainage from the fistula. However, in many patients with fistulas, the openings of the fistulas periodically close up, thereby causing the pus that normally drains out to collect inside. This, in turn, causes more inflammation in the tissues around the fistula and the anus, and an abscess can form. Anyone who has ever had a perianal abscess knows that it is exquisitely painful and can interfere with simple activities, such as sitting, walking, and sleeping. It can also become acutely painful during a bowel motion.

 

The abscess must then be drained by a surgeon or, in many instances, will go away once the fistula tract has opened again on its own. Recurrent inflammation in the perianal area can lead to scarring and damage, thus making it more difficult for the area to eventually heal.

 

 

Occasionally, surgeons may attempt to repair or close off the internal opening of a fistula where it comes through inside the anus or rectum. This is most often tried when the fistula connects the rectum and the vagina. The surgical procedure involves taking a flap of tissue that is partially cut out of the inner lining of the rectum and pulling it down and over the opening of the fistula that exists inside the rectum. The flap is sewn over the opening in an attempt to keep it in place. This type of operation, which under the best of circumstances has a fairly high failure rate of approximately 40% to 50%, should only be attempted if the rectum is free of active Crohn's disease and should only be performed by a surgeon experienced in the management of Crohn's disease fistulas.

 

 

 

For patients with severe perianal fistulas who do not respond to these measures or who have had damage to the anal sphincter, a diverting loop (temporary) ileostomy may be the operation that provides them with the best outcome.

 

By preventing stool from passing through the anus and the area of the fistulas and abscesses, this particular operation may result in a reduction in drainage from the fistulas, reduced abscess formation, and, in some cases, healing of the fistulas or surgical wounds left behind after drainage of an abscess. In those instances, the ileostomy may be reversed or closed and the fistulas will sometimes, but not always, remain healed.

 

 

For the patients with anal sphincter damage, closure of the ileostomy may not be feasible because incontinence will occur or the fistulas and abscesses may recur. In these cases, the loop ileostomy may be converted to a more permanent end ileostomy once the affected individual becomes accustomed to having a stoma. This type of ileostomy usually functions somewhat better than the temporary type and is easier for the individual to care for.

 

Removal of Rectum: When the rectum is left behind and not used for many years, there appears to be risk of cancer of the rectum. This can be difficult or impossible to screen for, and diagnosis usually occurs late and after the chance for cure has passed. As a result, most surgeons and gastroenterologists recommend that the rectum be removed electively before cancer has had a chance to develop. This is best done once the patient's nutritional state has improved and stabilized and once the patient is off medications, such as prednisone.