The liver has a dual blood supply from the hepatic artery and portal vein, in addition to the return flow from the hepatic venous system. The hepatic artery, portal vein, and hepatic vein form a dense vascular network in the liver, so control of bleeding in hepatectomy is the key to success or failure of surgery. Techniques such as laparoscopic suturing are not as good as open, thus making laparoscopic liver resection more difficult. Not all liver lesions are suitable for laparoscopic surgery. The best indications for laparoscopic liver resection are solid liver tumors <5 cm in diameter and located in the peripheral liver segments (2-6 segments), which are best performed by experienced surgeons; when the tumor is not easily resectable and may affect patient safety, it should be intermediate to open laparotomy. The success of completing laparoscopic hepatectomy lies in the control of bleeding from the liver section, and the key method for effective bleeding control includes the blockage of blood flow into the liver. The instruments and methods used for liver dissection management. Application of hemostatic materials for liver dissection. 1.Block of blood flow into the liver The left outer lobe of the liver can be resected by directly targeting the second and third segment of the Glission tip, by first detaching the hepatic bridge, separating the liver along the hepatic round ligament on the dirty side of the liver, and separating the third and second segment of the Glission tip upward at the angle of the left branch of the portal vein, and applying vascular clamps to close it. The rest of the liver can be resected using the traditional Pringle method, which is simple and quick to reduce hepatic parenchymal bleeding; regional hepatic blood flow block This method requires dissecting out the first and second hilum separately and disconnecting the hepatic artery, portal vein, and hepatic vein of the liver lobe to be resected. This technique allows clear marking of the hepatic pre resection line, finding the gap with the least amount of blood vessels between the lobes, controlling intraoperative bleeding similarly to total hepatic flow block, and does not affect the blood supply to the preserved side of the liver, with almost no effect on systemic hemodynamics. However, there are obvious disadvantages: the first is difficult and risky to implement and can easily lead to injury of its branches leading to bleeding, making the operation intermediate to open. During the operation, a combination of blunt and sharp methods is used for fine manipulation. The hepatoduodenal ligament is opened, and the plasma membrane on the surface of the hepatoduodenal ligament is opened sharply with an electric hook to dissect out the intrinsic hepatic artery, and the dissection continues upward along the intrinsic hepatic artery to reveal the right and left hepatic arteries and their bifurcations, at which point the corresponding hepatic arteries can be treated as needed. The portal vein is deeper and the bifurcation of the left and right portal veins is very high, so dissection is more difficult. The dissection of the second hepatic portal is difficult laparoscopically and can lead to uncontrollable intraoperative hemorrhage, so if there is no anatomical basis or if the intraoperative separation is slightly difficult, it should not be forced; Glission transection regional flow block. This technique is commonly used in open surgery, in which the hepatic artery, portal vein and bile duct of the lobe to be resected are severed outside the liver by lowering the hepatic portal plate and ligating the Glission tissues outside the liver, without the need to dissect the hepatic artery and portal vein separately, making open surgery simple and easy to perform. However, laparoscopic operation is not as flexible as open surgery and often requires a linear cutting closure. It increases the cost of surgery. 2.Commonly used instruments for laparoscopic liver dissection 1.Union application of ultrasonic knife and bipolar electrocoagulation The principle of ultrasonic oscillation ruptures the hepatocytes, while leaving a tough and dense duct structure, and then the corresponding treatment is performed according to the thickness of the duct. The left hand application of bipolar electrocoagulation can clamp the liver tissue and leave the pipeline structure, and the pipeline structure less than 3mm is directly separated by ultrasonic knife, and the pipeline structure larger than 3mm is applied with titanium clamps and vascular clamps to close. For local bleeding, hemostasis can be achieved by bipolar electrocoagulation. 2.Laparoscopic multifunctional surgical dissector is the most commonly used laparoscopic liver dissection instrument at present. It learns the advantages of CUSA applied in open surgery, and it makes up for the disadvantage that other instruments can only dissect but not attract. It can separate and dissect each tiny duct in the liver section in a short time and treat it accordingly. Moreover, it has electrocoagulation function to form a layer of crust after wound electrocoagulation, which can effectively control the bleeding of oozing and small vessels, and it can control bleeding in time by coagulation while cutting. The thicker blood vessels are closed with titanium clips or absorbable clips and then disconnected. 3.Ligasure vascular closure system is a more commonly used surgical instrument under laparoscopy, especially in laparoscopic spleen surgery, colorectal surgery, pancreatic surgery, but in laparoscopic liver surgery, the application effect is not very satisfactory, mainly because the operating head of Ligasue is relatively large, the liver tissue is brittle, each time the liver tissue is separated and severed more, not suitable for fine operation. 4.Linear cutting closure device For thinner liver tissue can effectively control hemostasis, for thicker liver tissue, there is a risk of damaging the intrahepatic ducts, but if the ultrasonic knife or multifunctional surgical dissector is applied to first separate the Glission of the liver lobe to be resected in the liver, and then apply the linear cutting closure device, it can achieve twice the result with half the effort. 3, hemostasis of liver section 1, electrocoagulation combined with saline rinsing There will be blood oozing from the section after liver dissection, mainly less than 2mm vascular bleeding, left hand suction flush to clarify the location of bleeding, then drip water on the bleeding point, right hand electric rod electrocoagulation to stop bleeding. Generally do not use the electric rod blindly in the liver trauma electrocoagulation, so that the hemostatic effect is not exact, and the formation of the scab is not solid. 2.Application of hemostatic material Laparoscopic liver resection, the abdominal cavity is under a certain pressure, small vascular bleeding will temporarily not bleed under the whole pressure, and bleeding in the section after the pressure is lifted, which is often not suitable to be detected intraoperatively. Therefore, hemostatic materials should be applied to the liver section. Clinically used absorbable hemostatic materials include fibrin glue, gelatin sponge, oxidized cellulose, microfibrillar collagen, chitosan and calcium alginate fiber, etc. Yu M. Du Z. Current research status and clinical application of absorbable hemostatic materials.