Portal gas in a diabetic patient under pharmacotherapy with an alpha-glucosidase inhibitor: report of a case with emphasis on US findings.

Portal gas is relatively rare, and its relation to ischemic bowel diseases has been emphasized. We report the case of a 56-year-old diabetic man under pharmacotherapy with an alpha-glucosidase inhibitor in which portal gas was incidentally detected by ultrasound (US). It showed multiple echo spots moving in the portal vein. Doppler signals confirmed them to be bidirectional and spiky, which immediately led to the diagnosis of portal gas. A change in oral antidiabetic drug caused the portal gas to disappear. We stress the usefulness of US and Doppler US for detecting and diagnosing portal gas. Although detailed analysis of a larger series of diabetic patients under this therapy is needed to draw a definitive conclusion, our observation merits attention. We also briefly review the literature.