CT findings of suspected anastomotic recurrence of Crohn's disease after ileocolic resection

Abstract

Objective To determine the utility of computed tomographic (CT) enteroclysis for characterization of the status of the anastomotic site in patients with Crohn's disease (CD) who have previously undergone ileocolic resection. Methods Totally 31 CD patients who had previously undergone ileocolic resection were enrolled in the study. After having been orally administered with isosmotic mannitol, the patients received CT scanning including plain scan, arterial phase scan, and portal venous phase scan. The abnormal CT findings were analyzed based on portal venous phase images. CT enteroclysis findings in 31 patients were evaluated by two radiologists in consensus. Endoscopic findings, histopathologic findings, and/or the Crohn's disease activity index (CDAI) were used as the reference criteria. Associations between CT enteroclysis findings and anastomotic site status were assessed. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT enteroclysis for the diagnosis of normal anastomosis versus anastomotic recurrence were estimated. Results Twenty-six cases and 5 cases were diagnosed as disease recurrence and normal anastomosis, respectively. In the disease recurrence group, 11 patients (42%) had lymphadenopathy (diameter＞ 1 cm) and 8 patients (31%) had peri-anastomotic fistulas, which were absent in normal anastomosis group, but the difference was not significant Anastomotic wall thickening more than 6 mm, marked mucosal enhancement, stratification, and peri-anastomotic stranding were found in 16 (62%), 19 (73%), 14 (54%), and 20 (77%) cases, respectively, in disease recurrence group, which were absent in normal anastomosis group ( all P ＜ 0.05 ). When the diagnosis of anastomotic recurrence was based on more than two of the following six variables, including lymphadenopathy, peri-anastomotic fistulas, anastomotic wall thickening more than 6 mm, marked mucosal enhancement, stratification, and peri-anastomotic stranding, its sensitivity, specificity, postive predictive value, negative predictive value, and accuracy yielded 88%, 100%, 100%, 63%, and 90%, respectively. The diagnostic accuracy of anostomotic stenosis with CT was only 53%. Conclusion CT enteroclysis yields objective and relatively specific morphologic criteria that help differentiate between recurrent disease and normal at the anastomotic site after ileocolic resection for CD. Key words: Crohn's disease; Multidetector computed tomography; Ileocolic anastomosis; Recurrence