Abstract OBJECTIVE:To investigate the improvement of splenectomy combined with peripancreatic vascular dissection. Methods:A modified in situ splenectomy was performed, in which the splenic hilum and perisplenic ligament were dissected close to the spleen while the spleen was kept in situ, and the short gastric vessels at the upper pole of the spleen were finally dissected. The peripancreatic vessels were dissected by a selective vascularization procedure that was performed in close proximity to the stomach and esophagus, preserving the anterior and posterior trunks of the vagus nerve. The portal vein was cannulated through the splenic vein, and heparin saline was continuously dripped into the portal vein to prevent thrombosis of the portal vein system. Results: In the 31 cases treated with this method, the free portal pressure (FPP) decreased by 8 cm of water column on average after surgery, and the average surgical bleeding volume was 420 mL. There were no surgical deaths, and there were no gastric emptying disorders and portal vein thrombosis in the recent postoperative period. There were no recurrent bleeding and hepatic encephalopathy at 12-36 months of follow-up, and 3 cases of sagittal portal vein thrombosis were found by color ultrasound at 6 months after surgery (9.68%). Conclusion:Three-approximation method of splenectomy with pericardial vascular dissection has less bleeding and can effectively reduce portal vein pressure; heparin saline drip via splenic vein cannulation can effectively reduce the incidence of postoperative portal vein thrombosis. Tian Mingguo, Department of Hepatobiliary Surgery, People’s Hospital of Ningxia Hui Autonomous Region Keywords Portal hypertension In situ splenectomy Selective periportal vascular dissection Portal vein thrombosis Triple-approximation method Since January 2005, we have implemented the improved splenectomy combined with periportal vascular dissection in 31 patients with portal hypertension with satisfactory results,which are reported as follows.1 Clinical data 1. 1 General data There are 31 cases in this group, The group consisted of 31 cases, including 21 males and 10 females, aged 28-58 years old, average 43 years old, all of them were patients with post hepatitis cirrhosis, accompanied by different degrees of splenomegaly and hypersplenism. There were 19 cases with history of ruptured esophagogastric fundal varices and bleeding, 8 cases of acute ruptured esophagogastric fundal varices and hemorrhage, and 4 cases of severe varices with red coloration detected by endoscopy. 17 cases of 31 cases were found with Child A, 12 cases with Child B, and 2 cases with Child C. 1.2 Methods of operation (1) In-situ splenectomy: an oblique incision was made into the abdomen under the left costal margin, and the spleen was inserted into the main portal vein through the right gastric omentum, and the right gastric omentum. The right gastric omentum was intubated into the main trunk of the portal vein, and the free portal pressure (FPP) was measured by the glass-water column method before splenectomy, after splenectomy, and after the flow was cut off, respectively. The splenic artery was ligated at the superior border of the pancreas, and the gastrosplenic ligament was cut along the greater curvature of the stomach to the left until all the short gastric blood vessels of the suprasplenic pole were dissected, and the subsequent steps were the same as those of the method of in situ splenectomy introduced by Sun Wenbing.1 When the suprasplenic pole and the fundus of the stomach were close to each other, the perisplenic ligament and tissues were dissected by pressing against the spleen in an anterior-to-backward and bottom-to-top order, and the blood vessels were ligated and then cut off, and then the suprasplenic pole was finally closed to the spleen and the short gastric vessels were cut off in the curved vascular clamp. Finally, a long curved vascular clamp was clamped tightly to the upper pole of the spleen, and the short gastric vessels were cut on the splenic side of the vascular clamp to remove the spleen. (2) Selective peripancreatic vascular dissection and preservation of the vagus nerve: the anterior plasma membrane of the esophagus was cut from the left side of the esophagus to the diaphragm from the right side upward, the anterior trunk of the vagus nerve was separated and lifted up, and the branches of the vagus nerve to the cardia and the lower part of the esophagus were cut off. After the vagus nerve was free, the blood vessels around the lower esophagus and upper stomach were dissected according to the selective vascularization methods reported in the literature.2,3 The blood vessels around the lower esophagus and upper stomach were dissected tightly against the esophagus and stomach. (3) Splenic vein cannulation: A 7F silicone catheter was inserted through the inferior pole of the splenic vein, to a depth of 5 cm, and the catheter was double-knotted and fixed from the splenic vein, and then led out from the left upper abdominal wall. The catheter of the abdominal segment was covered with a posterior peritoneal suture to prevent it from being dragged out by the peristalsis of the intestinal tract or when the drainage tube was removed in the postoperative period. The catheter was connected to a drug delivery pump outside the body, and anticoagulants were intended to be applied postoperatively. Heparin saline infusion via the splenic vein was started in the postoperative period if there was no obvious blood seepage, no obvious coagulation dysfunction was detected, and the platelet count reached 40×109/L or more. Heparin saline 100 ml (containing 50,000 units of heparin sodium) was injected into the intravenous self-control analgesic pump, and the infusion rate was set at 0.5 ml/h. The infusion was continued for more than 2 weeks, and the tube was removed after 3-4 weeks. If the platelet count was significantly elevated, enteric aspirin and Pansentin were given orally until the platelet count was reduced to normal.2 ResultsThe operation time of 31 patients ranged from 180 to 260 (220±126) min.Intraoperative bleeding ranged from 350 to 1,150 (420±438) ml.Most of the surgical bleeding was from the dissected peripheral blood vessels of the esophagus and fundus of the stomach, and there was very little bleeding from splenectomy.The postoperative FPP was lower than the preoperative FPP.The postoperative FPP was higher than the preoperative FPP. Postoperative FPP were all decreased compared with preoperative period, the decrease was 5~13 (8±3.5) cm water column. Two cases of mild hepatic encephalopathy and two cases of pleural effusion occurred postoperatively were cured after conservative treatment, with no surgical deaths, and there were no gastric emptying disorders or portal vein thrombosis in the recent period of surgery. No bleeding and catheter complications occurred after anticoagulation of splenic vein placement. Ultrasound Doppler follow-up examinations were performed at 3 weeks, 6 months, 1 year, and 3 years postoperatively, respectively. All cases were followed up within 6 months, and the follow-up rates at 1 and 3 years postoperatively were 87.1% (27/31) and 75% (18/24), respectively. Three cases of thrombus in the sagittal portion of the left branch of the portal vein were found at 6 months postoperatively, with an incidence rate of 9.68%; there was no significant change in the above three cases at 1 year postoperatively, and no thrombosis was found in the rest of the patients. There was no recurrence of bleeding and hepatic encephalopathy in the follow-up patients.3 DISCUSSIONTraditional splenectomy is to cut off all the ligaments and adherent tissues around the spleen first, and then ligate and cut off the splenic hilum after the splenic periphery is completely free. In portal hypertension, the vessels in the splenorenal, splenodiaphragmatic ligaments or adhesive tissues behind the spleen cannot be clamped, cut, or ligated under direct vision, and blunt separation by hand often results in massive bleeding. Sometimes the enlarged spleen is widely adherent to the surrounding tissues, and the collateral circulation is widely established, the splenic vessels and the blood vessels in the surrounding ligaments are dilated, and the blood vessel wall is thinned, forcibly removing the spleen will easily lead to tearing of the splenic hilum or laceration of the varicose blood vessels around the spleen, resulting in hemorrhage. Large bundle ligation of the splenic hilum and blind clamping after hemorrhage can easily damage the tail of the pancreas, resulting in serious complications such as postoperative pancreatic fistula and subphrenic infection. Moreover, the separation of the splenic hilum and the splenic pericardium will destroy the transportation branches between the splenic and renal veins that have been formed, and it has been reported that spontaneous shunts between the splenic and renal veins are formed in up to 9.3-13.8% of cases of portal hypertension.4,5 In addition, a large number of gastro-renal shunts of the collateral blood vessels pass through the periphery of the spleen.6 Damage to these collateral vessels during splenectomy will inevitably result in an insignificant decrease in or even an increase in the postoperative portal vein pressure. For this reason, we adopted in situ splenectomy by first treating the splenic hilum and freeing it close to the spleen. The advantages of this method are: (1) freeing it close to the spleen protects the collateral circulation that has already been formed; (2) it can preserve the long enough splenic vein, which makes it convenient to perform splenorenal venous shunt after splenectomy if the portal pressure does not drop significantly; the preservation of the long enough splenic vein also makes it possible to utilize its collateral branches to perform splenic venous cannulation; (3) it is not easy to damage the tail of the pancreas. In our group, amylase in the drainage fluid of the splenic fossa was routinely detected three days after the operation, which was negative; (4) less intraoperative bleeding. In practice, we found that most of the patients with portal hypertension have the upper pole of the spleen close to the fundus of the stomach, and at this time, it is very easy to cause hemorrhage by cutting off and ligating the short gastric blood vessels first, which often forces the surgeons to use splenic clamp to dissect the splenic pedicle in a hurry, which is easy to cause pancreatic injuries and damage to the collateral circulation. Only 9 of the 31 cases in our group successfully completed in situ splenectomy by the method1 reported in the literature, while 22 cases (71%) had only the short gastric blood vessels connected to the splenic hilum and splenic-kidney and spleno-colonic ligaments dissected, and at this time, a long-curved vascular clamp was clamped close to the splenic pole, and the short gastric blood vessels were cut on the splenic side of the clamp, which was both convenient and safe. In pericardia vascular dissection, attention is paid to the protection of paraesophageal portal vein, which has long been a consensus at home and abroad.2,3,7 Surgery only dissects the vein of the portal vein into the fundus of the stomach and the penetrating vein of the lower esophagus, which is not only effective in decompression of submucosal varices in the lower esophagus, but also preserves the spontaneous shunt channel of the organism. Inadvertent dissection of the paraesophageal transport branch vein will inevitably lead to a cutoff of the spontaneous portal shunt, thus counteracting the effect of splenectomy and left gastric artery dissection in lowering the portal pressure, and as a result, the postoperative portal pressure does not fall or even rises. Xie Min et al8 reported that portal venous pressure decreased significantly after selective pericardial vessel dissection compared with the preoperative period. A comparative study of selective pericardial vascular dissections and nonselective vascular dissections9 was conducted, and it was found that the postoperative pressure lowering effect of the former was significantly better than that of the latter. The postoperative portal vein pressure in our group also decreased in all cases, with an average decrease of 8 cm water column. However, due to the influence of traditional theories and technical limitations, the principle of “complete dissection” is still advocated in China for perigastric fundus esophageal collateral vessels including “high esophageal branches” and “ectopic high esophageal branches”, and the principle of “complete dissections” is still advocated in China for perigastric fundus esophageal collateral vessels. “Although this method can achieve the purpose of effective hemostasis, the natural shunt that has been formed is artificially destroyed, and the excessive postoperative portal pressure can easily promote the formation of new collateral vessels, which is an important factor causing recurrent bleeding in the postoperative period. We believe that the intraoperative “triple closeness” approach, which is close to the spleen, stomach, and lower esophagus, effectively protects the natural shunt and maintains the decrease in portal pressure due to splenectomy and left gastric artery dissection while effectively stopping hemorrhage. This dissection requires a more delicate technique and a longer operative time than the traditional method. In the initial stage, the surgeon should have enough patience, especially when dealing with the splenic portal vessels, and avoid forcing through the detachment forceps when the posterior aspect of the vessels has not been identified, and then detach the vessels one by one by using ligation followed by dissection after the vessels have been separated. Portal vein thrombosis is an important factor in the recurrence of esophageal and fundal varices after flow-breaking surgery. The dramatic increase in platelet count and the shortening of prothrombin time after dissecting surgery make it very easy to form thrombus in a short period of time. Wang Maochun et al10 reported that the most frequent occurrence of portal vein thrombosis was 11-18 days after surgery. Therefore, the use of anticoagulants in the early postoperative period is particularly important for the prevention of postoperative portal vein thrombosis. The proximal segment of the splenic vein, which has sluggish blood flow after the weaning procedure, is the most vulnerable site for thrombosis, which can be dislodged or grow gradually into the main trunk of the portal vein. Therefore, the proximal segment of the splenic vein is the key site to prevent thrombosis after surgery. Xue Laxzhou et al11 have reported that intraoperative cannulation through the splenic vein and continuous postoperative drip administration of low molecular dextrose resulted in no postoperative thrombosis in 36 patients, whereas thrombosis was formed in 13 of the 35 cases (27.14% ) in which this method was not used. The use of direct administration via splenic vein cannulation should be a better way to prevent portal vein thrombosis in the early postoperative period because of the high concentration of the drug in the portal and splenic veins and the low interference with the systemic coagulation mechanism. We have used daily heparin saline injections via splenic vein cannulation, which also resulted in a significant decrease in the rate of thrombosis.12 However, repeated extracorporeal injections are associated with the risk of portal phlebitis. Since 2007, we have switched to the use of an intravenous self-controlled analgesic pump for the administration of heparin, so that the heparin solution is injected continuously and slowly through this type of delivery pump. After the above application, we believe that this method can not only reduce nursing workload, but also play a lasting anticoagulant effect to achieve the purpose of effective prevention of portal vein thrombosis, intraoperative and postoperative operation is simple and easy to grasp, it is a more ideal method to prevent portal vein thrombosis after splenectomy combined with periportal vascular dissections of the cardia. References (omitted)