Use of carbon dioxide microbubble-enhanced sonographic angiography for transcatheter arterial chemoembolization of hepatocellular carcinoma.

Abstract
Our objective was to determine the usefulness of sonographic angiography with carbon dioxide microbubbles during transcatheter arterial chemoembolization for hepatocellular carcinoma. Thirty-four patients with hepatocellular carcinoma underwent sonographic angiography during transcatheter arterial chemoembolization. Digital subtraction angiography failed to reveal tumors in 27 patients. Tumor stain became obscure on digital subtraction angiography after the catheter was inserted into distal branches in seven patients. Sonographic angiography was performed after injection of carbon dioxide microbubbles into the hepatic artery selected for transcatheter arterial chemoembolization. In angiographically undetectable hepatocellular carcinomas, sonographic angiography revealed tumor vascularity in 17 patients in whom transcatheter arterial chemoembolization was then performed. For the two patients who underwent a second transcatheter arterial chemoembolization, the existence of alternative feeding vessels was confirmed by sonographic angiography. In the remaining 10 patients, tumor vascularity was not seen on sonographic angiography; percutaneous ethanol injection therapy was then performed. Sonographic angiography clearly revealed tumor vascularity in patients in whom staining became obscure on digital subtraction angiography after the catheter was inserted into a peripheral branch of the hepatic artery. In all 24 patients who underwent transcatheter arterial chemoembolization, sonographic angiography was useful for determining the artery suitable for transcatheter arterial chemoembolization and for monitoring tumor perfusion in the selected artery. Sonographic angiography can be used to determine not only the therapeutic strategy for treatment of hepatocellular carcinoma but also whether the tumor is supplied by the artery selected for transcatheter arterial chemoembolization, especially when the tumor is not revealed by digital subtraction angiography.