What is the role of surgery in treating Crohn's disease?
Although medical therapy is considered first line in the treatment of Crohn's disease, there are certain situations in which surgery is necessary. In fact, up to 75% of patients with Crohn's disease will require surgery at some point in the course of their disease. Surgery should not be looked at as a failure of therapy, but as a complement to medical therapy that is necessary in particular circumstances.
Indications for Surgery
Indications for surgery include:
- Perforation of intestine
- Fistula that is symptomatic and cannot be medically managed
- Uncontrollable bleeding from the intestine
- Symptomatic stricture
- Cancer or pre-cancer (dysplasia)
- Toxic megacolon (a potentially lethal form of acute colitis)
- Failure of medical therapy
- Steroid dependence
In some situations, such as when a patient has a short segment of small intestine involved or a superficial perianal fistula, a limited surgery may be preferable to long-term therapy with an anti-TNF inhibitor. The risks and benefits of both the medical and surgical option must be considered. It is important to remember that surgery is not a cure for Crohn's disease. In fact, it is common that patients will have a recurrence of their disease and symptoms at some point in the future, although in some patients this may not occur for a long period of time. The recurrence of the disease usually occurs at the area of intestine that was removed at surgery (anastomosis). For this reason, surgeons will remove the least amount of intestine possible.
The most common type of surgery is an intestinal resection. The surgeon removes just the area of affected intestine and reattaches the two healthy pieces of intestine. The area of the reattachment is called the anastomosis. As stated above, most patients who undergo bowel resection will have a recurrence of the Crohn's disease at the anastomosis. By five years after surgery, approximately 50% of patients will be symptomatic again. However, some patients may go years after surgery without any symptoms. Approximately 20% of patients will require another surgery by 10 years after the first.
After surgery, physicians may prescribe medications to help prevent or delay a recurrence of the Crohn's disease. Meraptopurine (6MP) and anti-
TNF therapy are probably the most effective medications in this situation. There is also short-term data on metronidazole and mixed results with mesalamine. Many gastroenterologists will perform a colonoscopy at six to 12 months after surgery to assess the anastomosis and terminal ileum. If there is significant endoscopic evidence of Crohn's disease in the small intestine proximal to the anastomosis, patients are at higher risk for recurrence of symptoms, and many physicians will recommend therapy immunomodulator or anti-TNF therapy in this situation.
Proctocolectomy and Ostomy
Unfortunately some patients have involvement of their entire colon and require total proctocolectomy (removal of the colon and rectum) and ileostomy. An ileostomy is where the ileum (small intestine) is brought through the abdominal wall to the skin's surface (stoma). The stoma is now where the stool exits the body and requires the patient to wear a pouch or bag to collect the waste. This pouch is emptied as needed multiple times a day. The stoma is usually located in the lower right abdomen above the belt-line and is not visible to other people. Patients with stomas enjoy a good quality of life and can have an active lifestyle. Additionally, if prior to surgery patients only had involvement of the colon and not the small intestine, the vast majority will not have a recurrence of the Crohn's disease. Those patients whose rectum is unaffected with Crohn's can have their small intestine attached to the rectum (ileorectal anastomosis) and continue to pass stool normally although with an increased frequency. In some cases of acute perforation of the intestine, a stoma may be created temporarily. Once the inflammation and infection has resolved, the stoma can be taken down and the bowel reattached.
In some cases where patients have strictures (scarred narrowings) of the intestines, bowel does not even have to be removed. The surgeon can perform a stricturoplasty, in which the lumen of the intestine is widened without cutting away a portion of the intestine. The strictured area of the intestine is cut lengthwise and then sewn up widthwise. This type of surgery preserves bowel length, but still accomplishes the goal of allowing the intestinal contents to pass by the restricted area.