Progressive atrophy in a deformed liver as a contributor to sigmoid volvulus.

The effect of a prior defect on secondary liver atrophy is unknown. We describe a case of sigmoid volvulus that was facilitated by progressive atrophy in a deformed liver. A 75-year-old man with abdominal pain and fullness was referred to our hospital. Computed tomography (CT) revealed reduced left hepatic lobe volume and a whirl sign, characteristic of sigmoid volvulus. The sigmoid volvulus was successfully detorted with endoscopy. Retrospective evaluation of liver morphology on CT and magnetic resonance imaging showed that the portal vein at the liver hilum was denuded due to a parenchymal defect of the medial segment, with compression by the crossing artery. As pulse Doppler ultrasonography demonstrated reduced portal blood flow in the region where liver atrophy developed, compression of the denuded portal vein presumably facilitated secondary atrophy and contributed to sigmoid volvulus. The present case shows that a deformed liver itself can be a cause of secondary atrophy. Therefore, continued monitoring of liver morphology and evaluation of portal blood flow to predict liver atrophy may be required, when an individual with a partial liver defect is encountered.