独立して合流する右後区域胆管枝と胆囊管との合流部に発生した結石に対する腹腔鏡下手術の1例

A case of confluence stone in the cystic duct and aberrant right posterior sectoral hepatic duct successfully treated laparoscopically

◆要旨：症例は72歳，男性．胃癌に対する開腹胃全摘，Roux-en-Y再建術の既往あり．血液検査で肝胆道系酵素の異常値を認め，精査目的に当科へ紹介となった．CT検査，MRI検査で，独立して総胆管に合流する右後区域胆管枝と胆囊管との合流部に嵌頓した結石を認め，合流部結石と診断した．胃切除後で内視鏡的なアプローチが困難なため，腹腔鏡下胆管截石術を施行した．胆囊を肝床から遊離した後，胆囊管を縦切開し結石へのアプローチを試みたが，結石を確認することができなかった．術中胆道造影を行ったところ，結石が割れて総胆管と右後区域胆管枝に落下していることを確認し，胆道鏡で截石した．本症例のような異所性胆管と胆囊管との合流部に発生した結石の報告はほとんどなく，非常に稀と考えられたので文献的考察を加え報告する．

　A 72-year-old man with a prior history of total gastrectomy for early gastric cancer was admitted to our hospital due to abnormal liver function test results without visible jaundice. Computed tomography and magnetic resonance cholangiopancreatography revealed a confluence stone located within the cystic duct joining the aberrant right posterior sectoral hepatic duct. Laparoscopic surgery was performed. After separating the gallbladder from the liver, the cystic duct was incised in order to expose the confluence stone. However, the confluence stone was not found between the cystic duct and the aberrant right posterior sectoral hepatic duct. Intraoperative cholangiography revealed that the stone had divided into two, and the two stones were present in the common bile duct and the right posterior sectoral hepatic duct separately. Choledocholithotomy under cholangioscopy was then performed. The postoperative course was uneventful, and the patient was discharged on postoperative day 11. In general, confluence stones are difficult to treat surgically due to the presence of local inflammation. Anatomical abnormalities of the bile duct therefore need to be investigated before surgery to select the most appropriate operative method to avoid intraoperative bile duct injury or postoperative bile duct stricture.