The Whirl CT Sign in Patient with Sigmoid Volvulus due Chagas' Disease.

It is believed that sigmoid volvulus (SV) in Brazil is a frequent complication of megacolon caused by Chagas' disease (CD), differing in some characteristics from volvulus found in other countries. Bowel obstruction in patients with CD, principally when the cause is SV, may be sometimes difficult to diagnosis exclusively with plain abdominal radiograph. Fecaloma impacted in retossigmoidal area is one of the differential diagnoses. In addition, the huge amount of gas and feces, and distension of the colon normally increase the difficulty to make the correct diagnostic. The use of computer tomography (CT) scan can easy elucidate the picture of SV, and can be a great tool in cases of patients with CD and suspicion of this entity. A 62-year-old man showed bowel distention and stop disposal of gas for 5 days. He had previous diagnosis of CD. He also had been suffering from chronic constipation for several years, including impacted fecaloma, with the necessity of manual extraction. Plain abdominal radiographs showed an important colon dilatation and gross amount of feces in the sigmoid colon. Abdominal computer tomography sacan revealed dilated colon filled with feces, as well, the "whirl sign" composed of mesentery and twisted colon. When abdominal radiograph films reveal gross colonic dilatation of unknown etiology in patients with CD, a whirl sign on CT scans raises the possibility of colonic volvulus.