Tumor immunomarkers such as CAl9-9 and CEA are significantly elevated in both benign and malignant liver diseases and are often used in the diagnosis and monitoring of patients with hepatoportal cholangiocarcinoma. Some studies have shown that their diagnostic sensitivity is up to 89% and specificity up to 86% old when combined with other diagnostic methods. In addition, the level of tumor markers correlates with the grade of the tumor, and higher levels mean less chance of surgical resection and lower survival rates. Ultrasonography has a high sensitivity for the diagnosis of bile duct dilatation, but is less able to diagnose the exact location of bile duct obstruction, lymph nodes, intrahepatic, and peritoneal metastases. a review study by Ruys et al. showed that although the accuracy of cT for the diagnosis of lymph node infiltration was limited, the accuracy for the diagnosis of bile duct, portal vein, and hepatic artery infiltration was over 80%. the typical signs of MRI are left and right The typical sign of MRI is a confined irregular soft tissue mass or irregular thickening of the duct wall at the intersection of the two hepatic ducts, which is also often accompanied by luminal narrowing, disruption, hepatic duct atrophy, and portal vein occlusion. ERCP and percutaneous hepatic cholangiopancreatography (PTC) have many similarities in the diagnosis and management of hilar cholangiocarcinoma; ERCP not only shows the anatomy of the biliary system and the extent of bile duct invasion, but also can be used for The sensitivity rate of MRCP in diagnosing hilar cholangiocarcinoma is 74%. Although the specificity of PET/CT for the diagnosis of lymph node and distant metastases in patients with hilar cholangiocarcinoma has been reported to be more than 80%, further studies are needed because of its limited utility for local resection. Expanded hepatic resection and preservation of adequate functional liver tissue are the current clinical decision dilemma. Because jaundice inhibits liver regeneration and as the volume of liver resection increases, the small size of the remnant liver and insufficient regeneration often lead to hepatic insufficiency and compromise the safety of the procedure and fatal complications such as postoperative liver failure. Patients with severe obstructive jaundice are immunocompromised, poorly tolerate anesthesia, and exhibit coagulation dysfunction and impaired nutritional absorption, all of which can decrease the survival rate of patients after surgery. Therefore, it is theoretically believed that preoperative biliary drainage is the ideal preparation to improve surgical safety and improve postoperative survival in patients with HC. However, as multicenter studies continue, some scholars believe that preoperative biliary drainage not only has limited positive effects, but also delays the timely treatment of the primary disease and increases postoperative infectious complications and morbidity and mortality. Recent meta-analysis studies also suggest that preoperative yellowing reduction is not routinely required for mid- and distal obstruction, and should only be considered in patients with proximal obstruction who are candidates for partial hepatectomy. Portal vein embolization was first proposed by Makuu-chi at the University of Tokyo. Because it promotes hypertrophy of the preexisting liver and avoids a sudden increase in portal pressure after hepatectomy, it is considered an effective measure to improve the resection rate of hilar cholangiocarcinoma and to reduce liver failure, offering the possibility of undergoing extended hepatectomy in patients with intermediate to advanced disease. This is especially true for patients with jaundice and a reserved functional liver volume of less than 30% to 40% of the total liver volume. Studies have shown that when the functional liver volume is less than 20%-40%, it prolongs the patient’s hospital stay and increases the morbidity and mortality rate. However, it should be noted that biliary drainage of the reserved liver segment should be performed prior to PVE to facilitate regeneration of the reserved liver, and care should be taken to prevent complications.