Post-operative colon and urinary diversions: surgical techniques, anatomy, and imaging findings Ashish P. Wasnik, 1 Nishant A. Patel, 1 Katherine E. Maturen, 1 Scott E. Regenbogen, 2 Ravi K. Kaza, 1 Mahmoud M. Al-Hawary 1 1 Department of Radiology, University of Michigan Health System, Ann Arbor, MI 48109, USA 2 Department of Surgery, University of Michigan Health System, Ann Arbor, MI 48109, USA Abstract This article discusses the commonly encountered opera- tive procedures of the colon and urinary diversions and provides a comprehensive review of indications, con- traindications, surgical techniques with emphasis on normal and abnormal multimodality imaging findings. Key words: Colectomy—Hemicolectomy—Urinary diversions— Cystectomy— Fluoroscopy—Imaging Given the increasing number and refinement of surgical procedures involving the bowel, there has been corre- sponding increased utilization of imaging in assessment of post-operative complications. Knowledge of the operative procedures, indications, and expected post-operative imaging features enables recognition of normal post-oper- ative appearances and accurate diagnosis of complications if present. This review article addresses the operative pro- cedures primarily in the colon including intestinal compo- nents of urinary diversions, with operative techniques, indications, contraindications, and imaging findings of ex- pected post-operative anatomy and complications. Segmental colectomy A right or left-sided segmental colectomy can be performed for a variety of indications. Currently, laparoscopic colectomy has become increasingly common, though there is wide geographic variation in its utilization [1]. The first laparoscopic colectomy was reported in 1991 [2] and sub- sequent studies have shown the benefit of laparoscopy in terms of complication rates while demonstrating equiva- lent surgical outcomes [3–5]. There have been multiple descriptions of varying laparoscopic techniques which are beyond the scope of this article and do not significantly impact the post-operative radiologic evaluation. Indications Segmental colectomy is commonly performed for malignancy, endoscopically unresectable polyps, diverti- culitis with or without complications, inflammatory bo- wel disease, colonic volvulus or refractory bleeding [6–8]. Contraindications In the event of acute obstruction secondary to colonic malignancy, surgery is undertaken solely to relieve the obstruction without performing an entire hemicolec- tomy. Contraindications to primary colonic anastomosis include distal obstruction, acute ischemia, severe inflammation, or feculent peritonitis. Relative con- traindications apply generally to laparoscopic opera- tions, with open surgery considered preferable in certain circumstances such as morbid obesity, locally advanced cancer, marked localized inflammatory process, carci- nomatosis, or extensive adhesions [6]. Technique (Fig. 1) Segmental colectomy involves colonic mobilization, vascular ligation, proximal and distal colonic transec- tion, and anastomosis. Depending on the clinical indi- cation and scenario, a proximal diverting loop ostomy may be performed to allow the primary anastomosis to heal with eventual takedown in 6–12 weeks. Depending on the indication for the procedure, mesenteric defect may be created. Larger mesenteric defects have an in- Correspondence to: Ashish P. Wasnik; email: ashishw@med.umich.edu ª Springer Science+Business Media New York 2016 Abdominal Radiology Abdom Radiol (2016) DOI: 10.1007/s00261-016-0880-y