An important reason for failure of TACE treatment is the formation of PVTT. Even if the tumor is small, the incidence of cancer thrombus in the portal vein is still high, and once the cancer thrombus is formed, it can cause intrahepatic dissemination. The portal vein trunk cancer thrombus can block about 80.0% of normal liver tissue blood supply, and TACE under such circumstances will cause further blockage of liver blood flow, resulting in acute liver failure and death. Therefore, theoretically, to prevent liver tissue necrosis, portal vein patency is a prerequisite for safe hepatic artery embolization, so there have been differences in the treatment of hepatocellular carcinoma with portal vein thrombosis. Some scholars have listed complete obstruction of the main trunk of portal vein as an absolute contraindication to TACE and incomplete obstruction of the main trunk as a relative contraindication. It is now believed that: 1. PVTT has a hepatic artery blood supply; 2. PVTT mostly cannot completely block portal blood flow; 3. When there is a cancerous thrombus in the portal vein, there is often a rich collateral circulation, and the small veins around the portal vein are tortuous and dilated, which is called “portal vein sponge formation”. It is believed that the state of liver function is an important factor, and patients with PVTT with good liver function can generally safely survive the risk of embolism; 6, patients with combined PVTT should be “super-selected” for TACE as much as possible. The study showed that PVTT mostly has hepatic artery blood supply, medical|education.com collects and organizes the iodine oil deposition in the cancer embolus after the iodine oil embolization chemotherapy via hepatic artery, and it is found that the accumulation of cancer embolus is positively correlated with its shrinkage ratio. When the cancer thrombus is located in the branch of the tumor-bearing portal vein, it is an absolute indication for TACE. The application of super-selective cannulation technique and chemoembolization of hepatic or subhepatic segments, which results in good iodine oil deposition within the cancer thrombus, can lead to its shrinkage or even disappearance. When the cancer thrombus is located within the main stem or primary branches, it was once considered a contraindication to TACE. However, clinical studies in recent years have found that TACE should not be considered a contraindication for cancer thrombi that do not completely obstruct the portal trunk, or completely obstruct the portal vein, but have formed a hepatic collateral circulation, especially when the cancer is confined to the hepatic segment. Segmental TACE is safe and effective for PVTT, which can improve the survival rate of patients. However, if the portal vein is completely obstructed, the collateral circulation has not yet been formed, and the cancer is huge, TACE will lead to severe liver failure. At this time, hepatic artery infusion chemotherapy (TAI) is effective, but its efficacy is lower than that of TACE.