Perihilar cholangiocarcinoma: a surgeon's perspective.

Perihilar cholangiocarcinoma (PHC) is defined anatomically as tumors located in the extrahepatic biliary tree proximal to the origin of the cystic duct. However, as the boundary between the extrahepatic and intrahepatic bile ducts is not well defined, PHC potentially includes two types of tumors: one is the extrahepatic type, which arises from the large hilar bile duct, and the other is the intrahepatic type, which has an intrahepatic component with invasion of the hepatic hilus. The new American Joint Commission on Cancer tumor-node-metastasis staging system for PHC was well revised; an important revision is that the Bismuth type IV was removed from T4 stage determinants. Most patients with PHC present with obstructive jaundice, and preoperative biliary drainage is mandatory. Previously, percutaneous transhepatic biliary drainage was used in many centers; however, it has been accepted that endoscopic nasobiliary drainage is the most suitable method for PHC. Recently, inside-stents have also been adopted for biliary drainage, with favorable results. Portal vein embolization is widely performed as presurgical treatment for patients undergoing extended hepatectomy to minimize postoperative liver dysfunction. Surgical resection of PHC is technically demanding and continues to be the most difficult challenge for hepatobiliary surgeons. Because of advances in diagnostic and surgical techniques, surgical outcomes and survival rates after resection have steadily improved. However, survival rates, especially for patients with lymph node metastasis, are unsatisfactory, and establishing a protocol for effective adjuvant chemotherapy is an urgent task. Further synergy of endoscopists, radiologists, oncologists, and surgeons is required to conquer this intractable disease.