Pouchitis: insight into the pathogenesis and clinical aspects

Abstract

Ulcerative colitis (UC) is a chronic intestinal inflammatory disease and familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease. Both diseases, despite being different, may require the same surgical procedure: proctocolectomy with ileal pouch-anal anastomosis (IPAA). The main complication after this procedure is pouch inflammation (pouchitis). This inflammatory complication can affect up to 60 percent of patients who receive IPAA for UC, and a very small percentage of the FAP patients. The purpose of this review was to determine the current molecular mechanisms in its pathogenesis and detail the risk factors involved in pouchitis, its diagnosis, and treatment.

Keywords: Ulcerative colitis; familial adenomatous polyposis; ileal pouch-anal anastomosis; pouchitis.

Figure 1

Proctocolectomy and ileal pouch-anal anastomosis (IPAA). A. Illustration showing the extension of the intestinal resection. All large intestine and rectum are removed, as evidenced in the follow-up between the red lines. B. Restorative proctocolectomy with J-shaped pouch and ileal pouch-anal anastomosis. C. Surgical aspect of an ileal J-shaped reservoir during a procedure, before performing a handsewn anastomosis (Colorectal Surgery Unit, Unicamp).

Figure 2

Endoscopic and radiological aspects of the ileal pouch. Endoscopic image of patients showing in (A) Normal mucosal appearance and in (B) Abnormal mucosa suggesting pouchitis. The endoscopic elements of the ileal pouchitis are granularity, loss of vascular pattern, edema, friability, mucosal hemorrhage, and superficial ulcers (Endoscopy Unit, Gastrocenter, Unicamp). Radiological aspects of the ileal pouch in the pouchogram, in (C) Frontal view (posteroanterior) and (D) Lateral view evidencing no abnormalities performed before ileostomy closure (Radiology Unit, Unicamp).