The role of intraoperative ultrasonography (IOU) in the surgical treatment of hilar cholangiocarcinoma
was explored in twenty-two patients, 17 males and 5 females. The mean age was
55 years (range 36-78 years). Preoperative imaging studies included abdominal ultra-sonography
and/or CT scan, and visceral angiography. Operations performed were segment III
bypass in 18 patients, local resection of tumour in 2 and resection of tumour en bloc with left
hepatectomy in 2. Interpretation of IOU in terms of vascular involvement by the tumour (as
compared to angiography or operative findings) was correct in 21 patients; no vascular invasion
in 20 and portal vein invasion in the remainder. One false negative result occurred in a patient
whose IOU failed to show right hepatic artery encasement by the tumour. When compared to
postoperative cholangiography or surgical specimen, IOU correctly demon-strated location and
extent of the tumours in all but one patient who had incomplete tumour resection. IOU was also
helpful in locating segment III duct for biliary bypass. The mean time used for IOU was 15.1 min
(range 10-20 min.), and there was no procedure-related com-plication. When supplemented with
operative exploration, IOU seems to be very useful in the assessment of the resectability of hilar
cholangiocarcinoma.