VM52 - Recognizing the Twist: Endoscopic Signs of Twisted Pouch Syndrome

Purpose/Background: Twisted pouch syndrome (TPS) is a newly described anatomical ileal pouch-anal anastomosis (IPAA) complication where an abnormal twisting of the pouch and its mesenteric axis results in bowel obstructive symptoms, erratic bowel habits, and severe abdominopelvic pain. Unfortunately, due to its rare presentation and unclassified pathology, TPS mainly remains unrecognized until surgical exploration, delaying diagnosis and treatment. Recognizing that a more effective preoperative diagnosis modality may bridge the current gap between diagnosis and treatment, we explored endoscopic findings that may aid in the preoperative diagnosis of TPS.

Methods/Interventions: Single-center review of peri-operative endoscopy video of adult patients diagnosed with TPS. All patients had a confirmed anatomical twist intraoperatively and were diagnosed with TPS. We included cases of TPS with varying anatomical twists.

Results/Outcomes: Case 1: Partial luminal occlusion at distal 1/3 of the pouch, resulting in the difficult endoscopic examination on insertion of scope. This luminal occlusion resulted due to a >90° twist in the distal body, typically from 180° – 360° clockwise. The anatomical twist was just proximal to anal anastomosis resulting in a spiraling occlusion that dilated with insufflation and collapsed with deflation, resembling a camera lens or eye dilation. Inflammation of the mucosa from mechanical partial obstruction and prolapse-like changes can be observed. After surgical correction, the prior pouch was anastomosed to the anus in a hand-sewn manner and the staple line was now straight.
Case 2: Twisting at mid-pouch with spiraling on staple line to a closed twisted lumen. Twisting creates a “waist” on the pouch that is difficult to traverse with the scope. Proximal to the waist, the pouch endoscopy appears normal. The retraction of scope past twist forces scope in a spiral fashion following the staple line.
Case 3: Twisting at the proximal pouch results in a long spiral of the staple line throughout most of the body of the pouch. In this patient, we can see a 360° spiral of the staple line as we travel through the pouch.

Conclusion/Discussion: We provided an endoscopic evaluation of three TPS cases with descriptive characteristics that will aid in the diagnosis of TPS and classify the location of the anatomical twist, based on its distinctive endoscopic signs. Our findings can serve as an endoscopic guide for quicker identification, faster referral to a pouch specialist, and earlier definitive treatment.