Characterization of Megapouch in Patients with Restorative Proctocolectomy

Background: Megapouch is a rare functional complication of restorative proctocolectomy with ileal pouch-anal anastomosis characterized by pouch ± small bowel dilatation with no evidence of obstruction on endoscopy and imaging. Little is known about clinical characteristics and outcomes of this entity.

Methods: We included all patients diagnosed with megapouch at our institution, identified from a pouch database. Data on baseline characteristics, management, and outcomes were documented and analyzed from electronic medical records. Appropriate statistical measures were used. p < 0.05 was considered significant.

Results: Twenty-three patients with megapouch were identified. The mean age was 40.7 years; 95.6% had underlying ulcerative colitis; most common indication for colectomy was medically refractory disease (56.5%). Abdominal pain (82.6%) and bloating (52.2%) were most common presenting symptoms. Most common finding on pouchoscopy was pouch dilatation (81.8%), while barium or gastrografin enemas and MRI/CT mostly revealed dilatation of pouch and/or small bowel. Fourteen (66.7%) patients required some forms of surgery-six patients required pouch excision and three required either pouch redo or revision. Rates of pouch failure and IBD-related 1-year hospitalization were higher among patients managed surgically versus those managed medically (p = 0.007 and 0.024, respectively), while need for escalation of IBD-therapy was comparable between the groups (p = 0.133). No deaths were reported and no patient had recurrence of megapouch. IPAA revision or redo did not lead to more IBD-related morbidity.

Conclusions: Majority of our patients with megapouch required surgery. In selected patients, redo pouch offered cure. Rates of pouch failure and IBD-related 1-year hospitalization were higher among patients managed surgically.