CASE 12533 Published on 18.03.2015

A colourachal fistula: a report of an unusual case


Uroradiology & genital male imaging

Case Type

Clinical Cases


Urbano Sebastian, Carrillo Colmenero Ana Mª , Rojas Vega J L, Ortiz Pegalajar C, Jiménez López Margarita

Jaén, Spain

41 years, male

Area of Interest Urinary Tract / Bladder, Abdomen ; Imaging Technique CT
Clinical History
A 41-year-old male patient presented with a two-day history of infraumbilical pain, associated with constipation, low fever, dysuria and nausea without vomiting. There was no previous abdominal surgery or other significant medical history.

Laboratory investigations showed a C-reactive protein of 1.92 mg/dl and a white blood cell count of 17.3x109/l.
Imaging Findings
Plain radiograph of the abdomen was interpreted as normal. Acute diverticulitis was suspected and abdominal CT examination was performed.

Findings CT: air-fluid collection in urachal remnant and peridiverticular (abscess), sigmoid colon wall and bladder thickening , in continuity with a colonic diverticulum.
Findings consistent with perforated diverticulitis.

After admission and start of antibiotic treatment, percutaneous drainage was performed, (interventional radiology) which produced purulent material.
The outcome was favourable, with good general condition, so he was discharged after ultrasound control (collection 25x20 mm).
Colonic diverticular disease is a public health problem becoming more prevalent, which increases with age.
In Western populations, a relationship between diverticular disease of the left colon and the lowest fibre intake has been observed.
Diverticula can occur anywhere thoughout the colon but are most common in the sigmoid. They represent small outpouchings of the colonic mucosa and submucosa through the muscular layer of the wall.
The term for inflammation of the diverticula wall is diverticulitis. Acute diverticulitis presents as fever, leukocytosis, abdominal pain, tenderness and constipation.
At CT, diverticulitis appears as segmental wall thickening and hyperaemia with inflammatory changes in the pericolic fat. The key to distinguishing diverticulitis from other inflammatory conditions that affect the colon (e.g. inflammatory bowel disease, ischaemia,..) is the presence of diverticula in the involved segment [1] .
CT also allows detection of other complications of diverticulitis such us diverticulitis abscess, colovesical fistula, stricture and perforation. CT is more sensitive than contrast enema examination. Infrequent complications described in the literature include colouterine fistula, colovaginal [2] and colo-urachal [3-10].
Urachal anomalies are uncommon defects arising either by incomplete obliteration of the urachus during the fetal period or by its reopening after postnatal regression. Five anomalies have been described: congenital patent urachus, urachal cyst, umbilical-urachal sinus, vesico-urachal diverticulum, and alternating sinus.

Differential diagnosis of diverticulitis [1] includes other causes of colonic inflammation (colon cancer, which has similar symptoms, epiploic appendagitis, inflammatory bowel disease, ischaemic colitis, graft versus host disease, infectious colitis, pseudomembranous colitis,...)

Usually medical therapy is sufficient to resolve the inflammation. If complications appear, i.e. perforation, colonic obstruction, abscess or bleeding, surgery can be the optimal approach.
CT can provide guidance for percutaneous drainage, which can eliminate the need for emergency surgery.
Differential Diagnosis List
Colo-urachal fistula
Colon cancer
Epiploic appendangitis
Final Diagnosis
Colo-urachal fistula
Case information
DOI: 10.1594/EURORAD/CASE.12533
ISSN: 1563-4086