金子 哲也, 中尾 昭公, 野本 周嗣, 奥田 直人, 原田 明生, 野浪 敏明, 高木 弘

Tetsuya KANEKO, Akimasa NAKAO, Shuji NOMOTO, Naoto OKUDA, Akio HARADA, Toshiaki NONAMI, Hiroshi TAKAGI

名古屋大学第2外科

Department of Surgery II, Faculty of Medicine, University of Nagoya

キーワード : Annular array, Bile duct neoplasms, Surgery, Ultrasonography

A 54-year-old woman with cancer of the lower bile duct was transferred to this institution on September 11, 1995 for further examination and treatment. External cholecystostomy had been performed at the previous hospital. Direct cholangiography via cholecystostomy showed circular stenosis at the intrapancreatic portion of the common bile duct. Endoscopic retrograde pancreatography showed no abnormal findings. Postcontrast computed tomography showed a low-density tumor at the intrapancreatic portion of the common bile duct, but invasion of the pancreas could not be confirmed. Endoscopic ultrasonography (EUS) showed a low echoic tumor measuring 20×25 mm at the lower bile duct. Preoperative EUS diagnosis included absence of infiltration to the pancreas, portal vein, duodenum, or lymph nodes, and abdominal angiography failed to detect the tumor. Surgery was performed on October 9, 1995, and sharp images were obtained with intraoperative ultrasonography (US) using a 7.5 MHz annular array probe after the laparotomy. The normal wall of the bile duct appeared as three layers. Obvious pancreatic infiltration by the lower bile duct cancer was identified on intraoperative US using an annular-array probe. Lymph nodes along the portal vein and the common hepatic artery were visualized with good resolution. Lymph-node metastasis was diagnosed as negative. On the basis of findings obtained with intraoperative US, an extended pancreaticoduodenectomy involving many lymph nodes was performed, and the extrapancreatic nerve plexus was dissected. Intraoperative US findings with the annular-array probe were confirmed on pathologic examination of the resected specimen. Pancreatic infiltration is an important factor in and a cause of local recurrence of cancer of the lower bile duct. Extended surgery is indicated when there is pancreatic infiltration in cancer of the lower bile duct. Thus accurate diagnosis of pancreatic infiltration is an important factor in the selection of operative strategy. Intraoperative US with annular an array probe proved useful in detecting pancreatic invasion that could not be confirmed by EUS or other imaging modalities.