Colovesical fistula

If nearby organs become involved, or if an abscess ruptures into a nearby organ, a fistula may result. Colovesical fistulae are the most frequent type, followed by colovaginal and, less commonly, by colocu-taneous fistulae. 

Complications of diverticulitis include diverticular abscess, colovesical fistula, and perforation. An abscess that occurs in up to 30% of cases appears as a hypodense fluid collection with a contrast-enhancing rim and surroimding inflammatory changes. It may contain air or air-fluid levels [47]. A colovesical fistula is suspected when air is seen in the bladder and there is thickening of the bladder wall adjacent to a diseased segment of bowel [52]. Another complication of diverticulitis can be focal contained perforations. They appear as small extraluminal deposits of air or extravasation of oral contrast material. Pneumoperitoneum is a rare finding in patients with diverticulitis [47]. 

Several cases of successful treatment of coloen-teral or colovesical fistulae have been reported. Apart from one author using an uncovered stent (Cwikiel and Andren-Sandberg 1993), all other investigators applied covered stents to seal the fistula (Choo et aL 1998 Repici et al. 2000 Lobato et al. 1999b Grunshaw and Ball 2001). 

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