The structures entering the first hepatic portal include portal vein, hepatic artery, common hepatic duct, nerves and lymphatic vessels, while the structures exiting the second hepatic portal include left hepatic vein, middle hepatic vein and right hepatic vein. For example, if the lesions of the first hepatic portal occur in the portal vein, such as portal vein spongiosis or portal vein trunk thrombosis, it may cause portal hypertension and eventually cirrhosis. Bile duct stones or bile duct tumors can cause obstructive jaundice or recurrent biliary duct infections, which may also eventually cause biliary cirrhosis, while lesions in the second hepatic portal can mainly cause Buga syndrome. The first and second hilum are also of great importance in surgery, with the first hilum being the most involved in surgery. By blocking the first hilum, the blood flow into the liver can be reduced, reducing traumatic bleeding during liver resection and making the anatomy clearer, which can reduce the risk of surgery. In some parts of the liver resection, it is also possible to block the second hepatic portal at the same time, which is also a whole liver blood flow block, but the blood flow block should also pay attention to the time, if it is too long, it is likely to cause more serious liver function damage, and even cause postoperative liver failure.