Colosalpingeal Fistula Diagnosed by Computed Tomography

Fistulous connections secondary to an acute episode of diverticulitis are not uncommon. Along with abscess formation, perforation, and obstruction, they are among the common surgical complications of this disease process. Although fistulas to the urinary bladder or vagina are seen occasionally,1 colon-to-fallopian tube connections are much less common1, 2 and generally are diagnosed either at surgery, barium enema, or hysterosalpingography.2, 3

Clinical Presentation 

A 63-year-old woman with APCKD status after renal transplantation, recurrent urinary tract infections, and a palpable tender pelvic mass was admitted to the gynecology service. Nonenhanced transverse computed tomography (CT) of the abdomen and pelvis was performed because of the patient's chronic renal insufficiency. CT showed findings consistent with an inflammatory process involving the sigmoid colon and adnexal structures. In addition, there was distention of the right fallopian tube (Figure A, arrows) and uterus (u), with preservation of the anatomy. The presence of adjacent pericolonic fat stranding and loculated extraluminal pneumoperitoneum further suggested an abscess or fistulous process. Coronal reformatted views showed gas distending the uterus with adjacent colonic diverticula (curved arrows) and extraluminal gas collection (Figure B, arrows).

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In the setting of inflammation involving the sigmoid colon with advanced diverticulosis, a diagnosis of colosalpingeal fistula was favored and confirmed on subsequent single-column, water-soluble enema (Figure C, arrows). Surgical salpingo-oophorectomy, hysterectomy, partial colectomy, and colpocleisis were performed and the diagnosis was confirmed during the surgery. The patient experienced no immediate postoperative complications and currently is being managed as an outpatient for recurrent urinary tract infections.

Discussion 

On review of the literature, we found several reported cases of colosalpingeal and colouterine fistulas. However, none described specific clinical or CT findings of colosalpingeal fistula. The diagnosis of this rare complication of diverticulitis was made by nonenhanced abdominal and pelvic CT, as a result of the findings of a gas-filled fallopian tube, diverticulosis, pericolonic inflammation, and extraluminal gas. The fistulous communication generally seen on barium enema or hysterosalpingogram showed this abnormality.2, 3

The CT findings in this case were helpful in allowing a rapid diagnosis to be made in a patient with a complicated medical history. Definitive identification of the colosalpingeal fistula complicating diverticulitis prevented an extended work-up and was essential in establishing preoperative coordination between the multiple surgical specialties.