Ultrasound monitoring of experimental ethanol injection into pig liver

Abstract

In percutaneous ethanol injection therapy, uncontrolled spread of ethanol sometimes causes complications. This study tested the accuracy of ultrasonography in showing the spread of ethanol during injection in normal postmortem pig livers. Methylene blue-stained 96% (vol) ethanol (0.5-2 ml) was injected into pig livers under sonographic control. The volumes of the sonographically determined areas infiltrated by the injections and the corresponding pale lesions seen after dissecting the livers were measured and compared. The locations of the stained areas were determined. Uncontrolled spread of ethanol was often seen sonographically as hyperechoic lines spreading centrifugally from the injection site. After dissection, nearly all vessels and ducts were stained blue, indicating a major escape of ethanol from the injection sites. The volumes of the sonographically determined injection areas were significantly larger (P < 0.001) than the lesions found after dissection. Ultrasonography may overestimate the spread of ethanol, making the survival of peripheral tumor cells possible.