How to Perform Curative Laparoscopic Hepatectomy for Intraoperatively Unidentified Hepatocellular Carcinoma.

BACKGROUND/AIM Detection of hepatocellular carcinoma using intraoperative ultrasonography (IOUS) is indispensable for successful laparoscopic hepatectomy (LH). This study was performed to evaluate patients with intraoperatively unidentified tumours undergoing LH. PATIENTS AND METHODS Seven patients who underwent LH for hepatocellular carcinoma and whose tumours were not detected using IOUS were included in this study. Clinical features, preoperative imaging, intraoperative imaging, surgical procedures, and pathological findings were evaluated. RESULTS Using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging, all the tumours were enhanced in the arterial phase and rapidly washed out, becoming hypointense to the remainder of the liver. All tumours except one were <2 cm in size. Severe liver fibrosis was observed in all cases. Tumours that were invisible on preoperative ultrasonography also could not be detected using IOUS or indocyanine green fluorescence imaging. Five patients underwent hepatectomy based on anatomical landmarks and achieved curative resection, whereas curative resection failed in two patients. CONCLUSION When tumours cannot be identified by IOUS, LH based on anatomical landmarks should be preferred. Importantly, invisible tumours on preoperative ultrasonography may not be identified intraoperatively during LH.