Ileal pouch-anal anastomosis surgery: imaging and intervention for post-operative complications

Ileal pouch-anal anastomosis (IPAA) surgery preserves fecal continence for improved quality of life in patients who require proctocolectomy for treatment of severe bowel diseases such as inflammatory disease and familial adenomatous polyposis. In IPAA surgery, an ileal reservoir, or pouch, is created and anastomosed to the anal canal. Awareness of the surgical technique and the postoperative anatomy of the IPAA is important to identify complications at computed tomography (CT), magnetic resonance (MR) imaging, and fluoroscopy. Complications include anastomotic leak, abscess, pouchitis, venous thrombus, pouch fistula, and stricture. Leaks from the blind end of the pouch and the pouch-anal anastomosis often result in pelvic abscesses, which may require ultrasonography- or CT-guided drainage; judicious catheter management can help improve clinical outcomes and avoid excessive imaging. Pouchitis may be identified by the presence of a thickened enhancing pouch wall and associated inflammatory changes and lymphadenopathy. The venous system must be scrutinized for thrombi secondary to surgical manipulation and sepsis. Fistulas are likely because of the presence of chronic inflammation or infection and may be seen at MR imaging, CT, or fluoroscopy. Strictures appear as areas of focal luminal narrowing with proximal dilatation, which can lead to obstruction. To avoid repeated exposure to radiation, MR imaging may be performed in patients who must undergo frequent imaging.