Crohn's Disease

Introduction to Crohn's Disease

Figure X | Image courtesy of GUT MICROBIOTA FOR HEALTH Opens in new window

Crohn's disease (abbreviated CD) is a lifelong inflammatory condition in which parts of the digestive system become inflamed. It's one type of a condition called inflammatory bowel disease (IBD) Opens in new window. CD can affect any portion of the gastrointestinal tract from the mouth to the anus. Most commonly, the small bowel, colon, or both are involved. Segmental disease is the rule with normal-appearing bowel intervening between involved areas.

The inflammatory process involves all layers of the bowel wall. Mucosal ulcerations, which can be small aphthous ulcers to linear “rake” ulcerations along the mesenteric aspects of the mucosa, are characteristic.

Ulcerated mucosa may be surrounded by normal-appearing mucosa. Confluence of ulcers can lead to a cobblestone mucosal appearance. The histologic appearance of involved bowel shows infiltration of all layers of the bowel primarily by lymphocytes. Noncaseating epithelioid granulatomas, found in about 50% of pathologic specimens, are considered pathognomonic.

Pathogenesis

The cause of CD is unknown, and there is no cure. The course of illness is generally characterized by exacerbations and remissions, but the disease tends to be slowly progressive. Surgical intervention is not curative; rather it is used to treat complications.

More than 70% of patients with CD undergo surgery at some point in the course of their disease. Fistulizing and cicatrizing disease are the most frequent pathologic findings associated with CD. Crohn’s disease most commonly involves the terminal ileum and cecum. Isolated colonic disease, usually with rectal sparing, occurs in about 25% of cases.

Crohn’s disease involving the colon and small bowel generally has the worst prognosis. Failure of medical therapy is the most frequent indication for elective surgical intervention. Intraabdominal abscess, fistula to the skin or adjacent organs, fulminant colitis, bleeding, free perforation, and cancer prevention (or treatment) are also less frequent indications for surgery.

Amelioration of extraintestinal manifestations alone is rarely a cause for operative management. International guidelines concerning when surgery is appropriate for patients with CD have recently been published.

Reoperative surgery is the rule rather than the except in the setting of CD. One third to more than half of CD patients have had at least one more surgery within 10 years of the initial intervention. Ileocolonic involvement is associated with the highest reoperation rate.

Clinical Pearls

Surgery for CD, whether primary or reoperative, should adhere to a number of common principles. Foremost among these, the surgeon must remember that CD is not cured by surgery.

Consideration of the possibility of future surgical intervention must be borne in mind when planning operative strategy. Surgery is performed for complications of CD.

More significant complications will require more complex and technically demanding surgery. Mortality and intestinal failure from CD is often related to operative misadventures. Resections should be limited in an effort to preserve intestinal function.

Numerous studies have shown that resection to macroscopically disease-free margins is sufficient. Stricturoplasty offers a durable, nonresectional solution when disease is quiescent and obstruction is the surgical indication. Surgery may have to be staged. Preoperative optimization of the patient is imperative. Optimization of nutritional status, including parental nutrition, when indicated, is mandatory.

Percutaneous drainage of preoperatively identified collections is desirable, and every effort should be made to accomplish this. The possibility of intestinal diversion, whether temporary or permanent, must be discussed with the patient preoperatively.