The use of intraoperative ultrasonography for detecting tumor extension in bile duct carcinoma.
The purpose of this study was to investigate the clinical feasibility of using intraoperative ultrasonography (IOUS) to detect tumor extension in bile duct carcinoma, especially longitudinal invasion along the bile ducts into either the hepatic parenchyma or adjacent hilar vessels.


METHODS
The medical records of 14 patients with bile duct carcinoma who underwent surgical treatment at the First Department of Surgery, University of the Ryukyus, were retrospectively analyzed. All patients were examined by IOUS during the operation. The resected specimens were processed in order to compare the ultrasound images with the histological findings.


RESULTS
The echo level of the primary lesion was not consistent. Specific echo patterns, such as a thickening of the echogenic layer (TEL) adjacent to the main tumor showing cancerous invasion, were observed in ten patients, 71.4% (nodular invasive 7, invasive 3) which were later confirmed by microscopic examinations and ultrasonic findings. The detection rate of TEL was 87.5% in nodular invasive type and 100% in invasive type, respectively. The TEL histologically coincided with a layer of fibrotic hypertrophy around the infiltrating tumor cells. The intramural invasion beyond the edge of TEL was detected in only 2 out of 11 patients. The accurate detection rate of the involvement of the portal vein and the hepatic artery by IOUS was 83.3% and 60%, respectively. Based on the above findings, IOUS is thus considered to be essential for evaluating tumor extension along the bile ducts, and also greatly helps in selection of the most appropriate operative procedure, especially in hilar cholangiocarcinoma.
Kusano
T
T
First Department of Surgery, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
Shimabukuro
M
M
Tamai
O
O
Miyazato
H
H
Shiraishi
M
M
Yamada
M
M
Muto
Y
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D014463:Ultrasonography