J Pouch: Imaging Findings, Surgical Variations, Natural History, and Common Complications.

Ileal pouch-anal anastomosis, or J pouch, surgery has become the procedure of choice for treatment of medically refractory ulcerative colitis and familial adenomatous polyposis. Overall, this operation is associated with a low rate of postoperative morbidity and good long-term function. However, when complications develop, there is a heavy reliance on imaging to facilitate an accurate diagnosis. Reported postoperative complication rates range from 5% to 35%. Complications generally can be categorized as structural, inflammatory, or neoplastic conditions. Structural complications include leaks, strictures, afferent and efferent limb syndromes, and pouch prolapse. Inflammatory conditions include cuffitis, pouchitis, and Crohn disease of the pouch. In addition, a variety of neoplastic conditions can develop in the pouch. Overall, pouchitis and leaks are the most common complications, occurring in up to 50% and 20% of individuals, respectively. Many imaging modalities are used to evaluate the J pouch and associated postoperative complications. The indications and various surgical techniques for J pouch surgery, normal postoperative appearance of the pouch, and most common associated complications are reviewed. In addition, the various imaging findings associated with J pouch surgery are described and illustrated. The radiologist's familiarity with the potential complications of the pouch can facilitate appropriate imaging, hasten an accurate diagnosis, and aid in rendering proper management. © RSNA, 2018.