Sigmoid Colon Perforation at CT Colonography Secondary to a Possible Obstructive Mechanism: Report of a Case

Abstract

We report a case of colonic perforation in CT colonography, which was observed in a sigmoid colon segment contained within an inguinal hernia. At surgery, apart from the perforation, a normal large-bowel wall was found. Although rare, perforation may occur in patients with normal bowel wall, possibly resulting from a mechanical strain caused by gaseous overdistention. Radiologists performing the procedure must be aware of this possibility.

Risk Factors for Colonic Perforation after Screening Computed Tomographic Colonography: A Multicentre Analysis and Review of the Literature

“…The insufflation technique is also important. The use of manual insufflation (rather than with an automatic insufflator) can increase colonic distension, with its associated increased risk of perforation, 6,7,10,11,14,15,17,18,20 and similarly an increased total volume of gas insufflated can potentiate perforation, whether this is due to too high an insufflation rate (higher than 2 L/minute) or for too long a period of time. 12 Ten metropolitan tertiary referral centres throughout the state of Victoria, Australia were reviewed for the number of cases of CT colonography performed in the preceding five-year period, with a total of 3458 such procedures undertaken.…”

“…Both patients were elderly and had undergone recent colonoscopy. Notably, one patient had diverticular disease, and one had recent colonic biopsy, both Hernia (inguinal or other involving large bowel) 8 -11 Connective tissue disorder/corticosteroid use 7 Recent colonoscopy 5,8 Recent colonic biopsy (+length of time since) 8,10,11,14 Previous colorectal surgery 6 Diverticular disease 5,10 -13 Active colon cancer 5,9 -11,14,15 Current or previous large bowel obstruction 8,16 -19 Other colonic disorder 7,8,10,11,18,20 Procedural factors Reduced institutional experience with colonography (number of cases) 6,10,11,21,22 Insufficient lubrication of rectal tube 8 Use of a rectal balloon 9 -11 Distention technique: manual (versus automatic) insufflation 6,7,10,11,14,15,17,18,20 Volume of insufflation (incorporating the rate and/or duration of insufflation)…”

Iatrogenic Colonic Perforation due to Computed Tomographic Colonography

“…Active colitis (inflammatory bowel disease or acute diverticulitis), recent colonic surgery or deep colonic biopsy or polypectomy/mucosal resection prior to CTC are considered to weaken the colonic wall [ 16 ]. Any cause of colonic obstruction, for example obstructive CRC or inguinal hernias, and specifically left-sided hernias containing the sigmoid colon, may predispose a patient to perforation due to overdistension [ 12 , 16 ].…”

“…To minimize complications arising from CTC, it is important to know the details of cases in whom those complications arise. However, only a few such cases have been reported in the literature [ 7 , 8 , 9 , 10 , 11 , 12 ]. Here, we describe two cases of colonic perforation secondary to CTC and present a brief review of the literature.…”

CT Colonography: Perforation Rates and Potential Radiation Risks

“…Obstructive or occlusive lesions such as due to carcinoma, diverticulosis, benign inflammatory stricture, and left inguinal hernia containing sigmoid colon have been found to be associated with perforation. Specific attention is recommended to the left groin in patients with known pre-existing left inguinal hernia during the insufflation process of CT colonography (12,13). Insufflation is discontinued if there is increase in size of the hernia sac.…”