Predicting difficulty in extending the ileal pouch to the anus in restorative proctocolectomy: investigation of a simple predictive method using computed tomography.

Aim: This study aimed to assess the ability of preoperative axial computed tomography (CT) to predict surgical difficulty in bringing the ileal pouch to the level of the anus during restorative proctocolectomy (RPC).
Method: Patients who underwent RPC with an ileal pouch-anal anastomosis (or ileal pouch-anal canal anastomosis) in our institution between January 2008 and April 2014 were enrolled. The patients were divided into two groups, including those in whom CT indicated potential difficulty in extending the pouch downwards (extension difficult (ED) group) and patients with no CT evidence of potential difficulty (normal group). The groups were compared for clinical factors and the thickness of the slices of CT showing the root of the superior mesenteric artery, the point of communication of the ileocaecal artery with the marginal artery (tICA) and the anal verge (AV). Receiver-operating characteristic analysis was performed, and a cut-off value was calculated for predicting the degree of difficulty in bringing the ileal pouch down to the anal canal.
Results: Thirty-four patients were entered in the study. The ED group included significantly taller patients and more with familial adenomatous polyposis than the normal group. The distance between tICA and AV was significantly longer in the ED group, with a cut-off of 21 cm giving a sensitivity of 100% and a specificity of 83.3%.
Conclusion: The distance between tICA and AV measured by axial CT can be a useful predictor for the difficulty in bringing the ileal pouch down to the anus during RPC.
(Colorectal Disease © 2016 The Association of Coloproctology of Great Britain and Ireland.)