Surgery for portal hypertension (PHT) in cirrhosis of the liver is different from any other abdominal surgery, in which the risk of postoperative complications, rebleeding, and death is greatly increased if the indications for surgery are not strictly controlled and the choice of surgical procedure is not rational.The rational choice of surgical procedure for PHT must be based on the hemodynamic changes in the patient’s portal vein. The most prominent hemodynamic manifestation of portal hypertension is elevated portal venous pressure, which is a major factor in the formation of esophagogastric fundal varices. Commonly used preoperative hemodynamic studies include Doppler ultrasound (DUS), endoscopy, spiral CT angiography (CTA), magnetic resonance portal vein system angiography (MRPVG), transarterial portal venography and hepatic vein cannulation for manometry and angiography. By carefully evaluating the results of the above studies, the correct choice of preoperative modality can be generally made. Wei Chen, Department of Biliary and Pancreatic Surgery, Shanghai Renji Hospital, Shanghai, China The majority of patients have a reasonable choice of treatment for PHT based on detailed preoperative hemodynamic studies. However, since the etiology and factors of hemodynamic changes are different in each patient, the combination of intraoperative portal pressure changes and preoperative hemodynamic study results in a more scientific and reasonable choice of surgical procedures and better surgical outcomes. After blocking the main trunk of the portal vein, the hepatic portal venous atresia pressure (HOPP) and the dirty portal venous atresia pressure (SOPP) can be measured and the maximum perfusion pressure (MPP) can be calculated, and MPP=SOPP-HOPP. MPP does not depend on the portal blood flow, but mainly reflects the volume of portal perfusion, and the larger the value is, the larger the volume of portal perfusion is, and the more the portal blood flow is to the liver; a negative value indicates that there is backflow of portal blood flow. If the value is negative, it means that the portal blood flow has backflow phenomenon, that is, there is a blood flow away from the liver, so this value has an important reference value for the surgical selection of PHT. Because of the difficulty and risk of the above pressure measurement methods, especially the measurement of HOPP must be performed by puncture pressure measurement of the hepatic portal vein after blocking the portal vein, which restricts the application of this method in the clinic. Intraoperative direct measurement of free portal pressure (FPP) is the most reliable method of reflecting portal pressure, which is an objective and quantitative index, and it is generally believed that only portal pressure ≥ 22 mmHg (30 cmH2O) may occur variceal rupture and bleeding. In contrast, western literature often uses hepatic venous gradient pressure (HVPG) ≥ 12 mmHg as the threshold for the occurrence of varicose veins and hemorrhage, and HVPG is the difference between hepatic venous embedded pressure (WHVP) and free hepatic venous pressure (FHVP), which is approximately equal to the free portal pressure (FPP) minus the inferior vena cava pressure, which averages about 7.35 mmHg (10 cmH2O); therefore, the bleeding threshold for patients with portal hypertension is higher than that of the patients in the domestic sector, which is about 7.35 mmHg (10 cmH2O). The bleeding threshold in patients with domestic portal hypertension is therefore 2-3 mmHg higher than that reported in the Western literature. If the surgical approach is selected on the basis of intraoperative FPP pressure changes, it is essential that the pressure measurement results are accurate. The traditional transgastric omental right vein puncture catheter is not easy to enter the superior mesenteric vein-portal vein, and the method of taking the zero point each time and reading the data by the water column method is unreliable, with a large error in the results, which greatly affects the accuracy. For this reason, we used the right branch of the middle colonic vein to insert the catheter into the superior mesenteric vein-portal vein, which was very easy to insert, and the length of the catheter inserted into the superior mesenteric vein-portal vein was easy to control, which was about 15 cm long. In addition, we connected the catheter to a pressure transducer, and the zero point was fixed at the level of the inferior vena cava, which allowed us to observe the pressure changes dynamically, and the results of the changes in different surgical phases were not affected except for the zero point, which might have a slight error.The time periods for the FPP measurement were after the opening of the abdomen, after the splenic artery ligature, after the splenectomy, after shunt, and after the weaning off of the flow. In order to investigate the relationship between the occurrence of postoperative rebleeding and encephalopathy and intraoperative portal pressure, as well as the guiding role of intraoperative portal pressure changes in the choice of surgical approach, we summarized the data of 170 cases who underwent pericardial vascular dissection and combined surgery in the past 7 years in our hospital, and divided the flow-breakage cases into the high-pressure group (postoperative FPP value ≥ 22 mmHg) and the low-pressure group (postoperative FPP value < 22 mmHg). According to the dynamic changes of intraoperative FPP values, we found that the differences in FPP values among the three groups of patients in the high-pressure group, low-pressure group, and combined surgery group after open surgery were not statistically significant. The FPP values of all three groups of patients after splenic artery ligation were significantly lower than after open abdomen, and the changes in FPP values of all three groups of patients after splenectomy were not significant. The mean increase in FPP values was greater in the high-pressure group after shunt ligation, and there was no longer a significant difference when compared with the post-opening period; whereas there was no significant change in FPP values in the low-pressure group. In the combined group, FPP values decreased significantly after completion of shunt surgery and increased after weaning, but the final FPP index was still significantly lower than that after opening, and there was no significant difference compared with that after weaning in the low-pressure group. From the postoperative follow-up results (4-69 months), there were 15 cases of rebleeding in the shunt-breaking group, in which the rate of rebleeding was significantly higher in the high-pressure group than in the low-pressure group and the combined group. There were 3 cases of postoperative rebleeding in the combined group, all of which occurred 1 year after surgery. MRPVG examination after hemorrhage control revealed splenorenal venous anastomosis embolization and esophagogastric fundus varices re-formation. In terms of the incidence of postoperative encephalopathy, there was no statistically significant difference between the low-pressure, high-pressure, and combined groups. Periportal vascular dissection is currently a commonly used procedure for the treatment of portal hypertension, but the incidence of postoperative rebleeding is high. The reason for this may be related to the persistent state of portal hypertension after dissection, which leads to the reappearance of collateral circulation in the portal system, reoccurrence of esophagogastric fundic variceal rupture and bleeding, and portal hypertensive gastropathy (PHG). Our study showed that the level of portal vein pressure after flow-breaking surgery largely determines whether rebleeding occurs after surgery. The risk of postoperative rebleeding was significantly higher in cases with FPP ≥ 22 mmHg after flow-breaking surgery than in cases with FPP < 22 mmHg. Therefore, the goal is to reduce the FPP to less than 22 mmHg, regardless of the procedure used. No shunt surgery can be considered when the FPP falls below the threshold level for bleeding after a shunt procedure. FPP in patients with cirrhotic portal hypertension depends primarily on intrahepatic resistance, collateral vascular resistance, and visceral blood flow in the abdominal cavity. The essence of splenic artery ligation and splenectomy is a flow-reducing procedure that reduces portal blood flow by 25% ~ 40% while correcting hypersplenism. In fact, the decrease in FPP after splenic artery ligation is the most pronounced decrease in pressure during the entire surgical procedure for portal hypertension, and the change in FPP after splenectomy is not significant compared with that after splenic artery ligation. If the degree of increased intrahepatic resistance is mild and there is still more blood flow to the liver, the decrease in FPP after splenic artery ligation is more pronounced, indicating that the increase in splenic artery flow accounts for a greater proportion of the FPP, and there is essentially no change in FPP after splenectomy and weaning, and after weaning, the FPP value is mostly < 22 mm Hg, and additional shunting is usually not required; if the intrahepatic resistance is greater, and there is a greater number of spontaneous portal shunts, then the splenic If the intrahepatic resistance is high and the spontaneous portal shunt is high, then the decrease of FPP after splenic artery ligation is small, and the FPP value after bypass is mostly ≥ 22 mm Hg. The FPP value after splenic artery ligation plays an important role in the choice of the surgical procedure, and if the decrease of FPP value is very obvious compared with that after laparotomy, or if the FPP value is lower than the threshold of hemorrhage (22 mm Hg) by 2-3 mm Hg, then bypass is feasible, or else the combination of shunt and bypass is usually needed. There are different reports on the sequence of operation between shunt and truncus. Since the decrease of FPP after splenic artery ligation is the most obvious decrease of pressure during the whole operation, if FPP fails to fall within the hemorrhagic threshold after ligation of the splenic artery, especially if the FPP remains unchanged or rises after splenectomy, then consideration should be given to adding splenico-renal vein shunt, because the subsequent operation will not only not decrease the portal pressure but will also slightly increase the pressure of portal vein. On the contrary, it will rise slightly. We usually perform splenorenal vein anastomosis first, because the decrease of FPP can make the operation of shunt easier; if the other way around, it is easy to bleed during the operation of shunt, and if the operation of shunt is prolonged, it may lead to splenic vein thrombosis. If it is not possible to determine whether shunt operation is necessary after splenectomy, shunt operation can be performed first, and then decide whether to perform shunt operation according to the change of FPP value and splenic vein tension.