Three-dimensional Pouchography: A Proof-of-concept Study of a Breakthrough Technique for Visualising Ileoanal Pouch Anatomy and Morphology in Normal and Mechanical Pouch Complication Patients

Abstract

Background Herein, we present a proof-of-concept study of 3-dimensional (3D) pouchography using virtual and printed 3D models of ileal pouch-anal anastomosis (IPAA) in patients with normal pouches and in cases of mechanical pouch complications. Materials & Methods We performed a retrospective, descriptive case series of a convenience sample of 10 pouch patients with or without pouch dysfunction who had CT scans appropriate for segmentation were identified from our pouch registry. The steps involved in clinician-driven automated 3D reconstruction are presented. Results Three patients who underwent CT imaging and were found to have no primary pouch pathology, and seven patients with known pouch pathology identifiable with 3D reconstruction including pouch strictures, megapouch, pouch volvulus, and twisted pouches underwent 3D virtual modeling; one normal and one twisted pouch were 3D printed. We discovered that 3D pouchography reliably identified staple lines (pouch body, anorectal circular and transverse, and tip of J), the relationship between staple lines, and variations in pouch morphology, and pouch pathology. Conclusions Three-dimensional reconstruction of IPAA morphology is highly feasible using readily available technology. In our practice, we have found 3D pouchography to be an extremely useful adjunct to diagnose various mechanical pouch complications and improve planning for pouch salvage strategies. Given its ease of use and helpfulness in understanding the pouch structure and function, we have started to routinely integrate 3D pouchography into our clinical pouch referral practice. Further study is needed to formally assess to value of this technique to aid in the diagnosis of pouch pathology.