Usefulness of sonazoid–ultrasonography during hepatectomy in patients with liver tumors: A preliminary study

Abstract

To improve diagnostic accuracy of intraoperative ultrasonography (IOUS), we investigated the usefulness of new contrast medium of microbubble agent, Sonazoid as a preliminary study. We examined IOUS in 50 patients with liver tumors who underwent hepatectomy. Sonazoid was administrated intravenously and Kupffer-phase images of the tumor were observed before hepatectomy. Sonazoid was reinjected to observe the tumor vasculature. The tumors included hepatocellular carcinoma (HCC) in 25 patients, intrahepatic cholangiocarcinoma in 3, colorectal liver metastasis in 14, gastrointestinal stromal tumor in 1, and benign hematoma in 1. Liver tumors were clearly detected as perfusion defect in most cases. Small lesions (<1 cm), extra-capsular tumor growth, and portal vein tumor thrombus were also clearly detected on the Sonazoid-IOUS. Small occult tumors were detected in five cases. Differential diagnosis with suspicious non-tumorous lesions and benign mass was possible based on vascular findings at the early phase. In comparison with hepatectomy for HCC under conventional IOUS, the proportion of patients with positive surgical margin (0%) tended to be lower than that of the control group (P = 0.073). Sonazoid-IOUS is a promising useful tool to detect the precise tumor margin and small tumors, hence allowing curative hepatectomy or intraoperative ablation.