portal shunt

Portal shunt is used for surgical treatment of portal hypertension. Portal hypertension is the result of impeded blood flow to the portal system. The main clinical manifestations are congestive splenomegaly, hypersplenism, gastric fundus and esophageal varices, and a large amount of hematemesis after varicose vein rupture, which can be life-threatening. It can also cause ascites. There are many surgical methods for reducing portal pressure. The procedures for treating portal hypertension in children can be classified into the following two categories: 1. Surgery to reduce portal vein blood flow: including splenectomy, which may contain more than 40% of portal vein blood flow after splenomegaly. Therefore, the splenectomy can temporarily reduce the pressure of the portal vein. 2 shunt surgery: the portal vein or its main branch and the inferior vena cava and its main branch line anastomosis, so that the higher pressure portal vein blood is shunted to the lower pressure vena cava system. Regarding the choice of surgery, simple splenectomy is not commonly used because of the failure to resolve the problem of portal hypertension and the risk of fulminant infection after surgery. Shunt surgery is often used, generally considered intrahepatic portal hypertension esophageal varices, had upper gastrointestinal bleeding, suitable for spleno-renal venous shunt and portal vein shunt. For pre-hepatic portal hypertension, most of the portal vein is embolized, which is suitable for spleno-renal venous shunt or superior mesenteric vein and inferior vena cava shunt. Treatment of diseases: portal hypertension Indication 1. Due to thrombosis in the splenic vein, spleno-renal venous shunt cannot be performed. 2. The spleen and the lateral peritoneum and diaphragm are rich in collateral circulation. In this case, splenectomy has been difficult, and more collateral circulation will be destroyed during spleen removal. 3. When the spleen has been resected and then hemorrhage again. Contraindications 1. Poor liver function, plasma albumin protein is less than 30g / L, serum bilirubin is higher than 10mg / L, sick children have jaundice. 2. Combined ascites, no improvement after treatment. 3. Less than 3 years old, due to the thin blood vessels, shunt surgery is not easy to succeed, there are relative surgical contraindications. However, in recent years, the literature reported that age is too small is not a surgical contraindication. Preoperative preparation 1. Patients with poor liver function should strengthen liver protection measures before surgery, including high protein, high calorie, high vitamin and low salt diet. 2. When the plasma protein is low, blood transfusion, plasma and albumin may be administered in small amounts. 3. Intestinal preparation 3 days before surgery, oral administration of neomycin, metronidazole, reducing the number of intestinal bacteria. 4. Preoperative B-ultrasound and other renal function tests to understand the functional status of the kidneys. Surgical procedure 1. Incision: transverse incision in the upper abdomen 2. Exposing the portal vein: The liver is pulled upward, and there is often a swollen lymph node at the hepatoduodenal ligament, which is best removed. The peritoneal layer of the hepatoduodenal ligament is longitudinally separated, and the common bile duct is pulled to the left side, and the portal vein is easily found behind the common bile duct. The portal vein was bluntly separated for one week and isolated to the upper edge of the pancreas. Continue to expose the superior mesenteric vein, and clamp the upper and lower ends of the portal vein with a non-injured right-angled vascular clamp. 3. Cut the peritoneum on the right side of the spine and bluntly separate the inferior vena cava for half a week. The portal vein trunk was cut 1 cm before the venous bifurcation in the proximal hepatic department, and the proximal end was properly ligated with a 4th wire. The distal portal vein sutures two traction lines. To enlarge the diameter of the anastomosis, part of the portal vein wall can be obliquely removed. In the corresponding inferior vena cava, a part of the blood vessel wall was clamped by a non-damaged vascular clamp, and in the portion of the jaw, the inferior vena cava wall was longitudinally cut into a length of 1.5 cm. 4. Suture the portal vein and the posterior wall of the inferior vena cava with a 5-0 non-invasive nylon thread prolene (or silk). The knot is attached to the outside of the vessel and then turned to the anterior wall for continuous or intermittent valgus suture. After the anastomosis is completed, the vascular clamp on the inferior vena cava side is relaxed, and then the vascular clamp on the side of the portal vein is released. At this time, there may be a small amount of active bleeding from the anastomotic needle between the needles, generally can be pressed with warm saline gauze for a while, more natural hemostasis; if not effective, you can make a stitch at the bleeding site, you can stop bleeding. Others advocate side-to-side shunt surgery. After separating the portal vein and inferior vena cava during operation, longitudinally clamp a part of the portal vein and the inferior vena cava wall, and close the two clamps (or clamp the two vessel walls with a special three-leaf vascular anastomosis clamp), and clamp the upper and lower parts of the clamp The end vessel wall was sutured with a 5-needle pull line with a 5-0 Prolene suture. Then, the inferior vena cava and portal vein were respectively cut at the corresponding sites, and the posterior wall of the blood vessel was sutured by a 5-0 Prolene line, and then the anterior wall was sutured. Lateral shunt can control the size of the anastomosis according to the condition of the portal hypertension. Generally, the anastomosis can be around 1cm. complication 1. Intrahepatic portal hypertension, divergence often occurs in different degrees of liver function decline, severe jaundice, ascites or even hepatic coma, especially after portal shunt, the mortality rate is higher. 2. Patients with poor liver function, active liver protection treatment. 3. After intrahepatic portal hypertension is performed after portal shunt, some children may have cranial nerve symptoms ranging from mild to severe (especially after eating meat), which is related to the increase of ammonia nitrogen in the surrounding circulation. After the shunt, the ammonia derived from the intestine is absorbed and no longer undergoes detoxification into urea by the liver, but directly enters the peripheral circulation, affecting the metabolism of the central nervous system, thereby causing symptoms of the cranial nervous system. Symptoms often appear 15 to 30 days after surgery, mild dizziness, headache, memory loss, when there is fear of cold; moderate cranial nerve symptoms are slow response, lethargy, intermittent neurological disorders, subconscious movements; Stupor state or coma. In addition to fasting meat, intravenous sodium glutamate can be administered to reduce blood and nitrogen levels. In addition, intravenous antibiotics should be administered to inhibit intestinal bacteria and reduce ammonia formation. Methods for reducing sputum sigmoid anastomosis in adults to remove large colons or to perform right hemicolectomy to reduce ammonia formation are not commonly used in children.