Evaluation of Endoscopic and Imaging Modalities in the Diagnosis of Structural Disorders of the Ileal Pouch

Background: Computerized tomography enterography (CTE), gastrograffin enema (GCE), magnetic resonance imaging (MRI), and pouch endoscopy (PES) have commonly been used to assess Heal pouch disorders. However, their diagnostic utility has not been systematically evaluated. The aims of this study were to compare these imaging techniques to each other and to optimize diagnosis of pouch disorders by using a combination of these diagnostic modalities. Methods: Clinical data of patients from the Pouchitis Clinic from 2003 to 2008 who had a PES and at least 1 additional imaging modalities (CTE, GGE, or MRI) used for evaluation of Heal pouch disorders were retrospectively evaluated. We analyzed the accuracy, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) with which these tests were able diagnose pouch inlet and distal small bowel and pouch outlet strictures, pouch fistulas, sinuses, and leaks. Subsequently, accuracy was recalculated by combining 2 imaging modalities to see if this could enhance accuracy. Results: A total of 66 patients underwent evaluation with PES and I other imaging modality as follows: PES + CTE (n = 23), PES + GGE (n = 34), and PES + MRI (n = 26). The mean age was 41.5 +/- 14.5 years, with 28 being female (42.4%). Sixty patients (90.9%) had J pouches and 59 (89.4%) had a preoperative diagnosis of ulcerative colitis. Overall, CTE, GGE, MRI, and PES all had reasonable accuracy for the diagnosis of small bowel and inlet strictures (73.9%-95.4%), outlet strictures (87.9%-92.3%), fistula (76.9%-84.8%), sinus (68.0%-93.9%), and pouch leak (83-93.9%). CTE had the lowest accuracy for small bowel and inlet strictures (73.9%) and MRI had the lowest accuracy for pouch sinus (68.0%). Combining 2 imaging tests can increase the accuracy of diagnosis to 100% for strictures, fistulas, sinus, and pouch leaks. Conclusions: CTE, GGE, MRI, and PES offer complementary information on disorders of the pouch and the combination of these tests increases diagnostic accuracy for complex cases.