[Colovesical fistula caused by diverticulitis of the sigmoid colon: diagnosis and treatment]

Colovesical fistulas caused by diverticulitis of the sigmoid colon are a rare but complex disease for which there is so far no diagnostic and therapeutic algorithm. The goal of this retrospective study including long-term follow-up was to find an algorithm for the diagnosis and therapy of colovesical fistulas caused by diverticular disease.

Between 1982 and 2010 a total of 54 patients (46 male and 8 female) were treated in this institute for a colovesical fistula caused by diverticulitis of the sigmoid colon. The validity of the following diagnostic procedures was considered: poppy seed test, abdominal computed tomography (CT), cystoscopy, coloscopy, cystography and colon enema. The one stage operation included resection of the inflamed colon and a two-lined hand sewn end to end anastomosis of the colon without protective colostomy. After excision of the fistula a two-lined closure of the bladder defect was carried out followed by insertion of a catheter for 7 days. During follow-up patients were examined for recurrence of diverticulitis and colovesical fistula.

At primary clinical presentation all patients showed clinical symptoms of recurrent urinary tract infections, 74.1% had pneumaturia and 53.7% fecaluria. Fistula detection rates were 94.8% for the poppy seed test, 58.7% for CT scanning, 19.4% for cystography, 38.6% for colon enema, 15.1% for cystoscopy and 9.6% for coloscopy. Of the patients 6 (11.1%) showed perioperative morbidity (3 pneumonia and 3 superficial wound infections) and mortality was 0%. After surgical intervention no recurring diverticulitis or fistulas were detected within a median follow-up period of 62 months (range 1-164 months).

The poppy seed test is the most reliable diagnostic method for the detection of colovesical fistulas. The one-stage resection of the fistula of the colon and bladder segment without protective colostomy is safe and feasible.