OVERVIEW
Prehepatic portal hypertension, also known as prehepatic portal hypertension syndrome, is a chronic, partial obstruction of blood flow in the portal vein system due to embolization of the main trunk of the portal vein and splenic vein, which leads to elevated portal venous pressure and subsequent dilatation of the short gastric vein, fundic vein, coronary vein and esophageal vein. The disease is more common in children, and most cases of portal hypertension in adults are caused by intrahepatic lesions with cirrhosis and other liver function impairment.
Etiology
1. Congenital malformations, such as atresia, stenosis of the main trunk of the portal vein or angiomatous lesions of the portal vein.
2. Neonatal umbilical phlebitis.
3. Intra-abdominal infections, such as appendicitis and cholecystitis.
4. Trauma near the portal vein and splenic vein causing thrombosis of the main trunk of the portal vein, occlusion of the portal vein, and elevated portal vein pressure.
5. Arteriovenous fistula formation between the hepatic artery and the portal vein system can also lead to the development of this disease.
Symptoms
The main symptoms are splenomegaly with varying degrees of hypersplenism, esophageal varices, vomiting blood, blood in the stool, and ascites. However, the hardness and size of the liver and liver function are normal.
1. Splenomegaly and hypersplenism
All patients have different degrees of splenomegaly, most of them are moderately enlarged, and the lower pole of the largest spleen can reach the pelvis, and its hardness depends on the duration of portal hypertension. The hardness depends on the duration of portal hypertension. It is usually accompanied by hypersplenism and clinical anemia of different degrees, with markedly reduced platelet and white blood cell counts.
2. Abdominal pain
Commonly seen in patients with acute portal vein thrombosis, mostly distension and pain in the upper abdomen, especially after meals.
3. Esophageal varices combined with rupture and bleeding
Once the varices of esophageal and fundic veins rupture, the patient will vomit a lot of blood and have black stool. Due to elevated portal pressure, impaired coagulation mechanism and thrombocytopenia, the bleeding is often difficult to stop on its own.
4. Ascites
Patients often have different degrees of ascites, which is manifested as abdominal distension, decreased urine volume and dark yellow color of urine.
5. Other symptoms
Dyspepsia, lack of appetite, etc. Occasionally, subcutaneous hemorrhagic spots and other hemorrhagic symptoms can be seen, and hepatic encephalopathy does not usually occur in children.
Examination
1. Laboratory examination
The white blood cell and platelet counts are obviously reduced, and there may be anemia, most of which is orthocytosis and a few of which are normocytosis and hypocytosis. Liver function indexes are mostly normal or mildly abnormal.
2. Imaging examination
(1) X-ray barium meal or gastroscopy: esophageal and fundal varices can be found.
(2) Doppler ultrasonography: ① the lumen of the portal vein trunk and its main branches are not clear; ② the first hilar shows a honeycomb-like echogenic area with blood flow signals.
(3) CT and magnetic resonance imaging (MRI): Obstructive portal vein lesions, splenomegaly, ascites, etc. can be seen.
3. Percutaneous splenic portal vein angiography
This is an invasive test that can rapidly investigate the portal vein system, especially for prehepatic portal hypertension. The examination can determine the site of portal vein obstruction, understand the collateral circulation of the portal-body vein and select the veins that can be utilized, and at the same time, it can measure the splenic medullary pressure and portal vein pressure, which is helpful for the diagnosis of pathologic localization.
4. Liver puncture biopsy
Liver tissue is mostly free of cirrhotic manifestations and pseudofollicular formation.
Diagnosis
According to the patients’ history of portal vein thrombosis, clinical manifestations such as splenomegaly and hypersplenism, combined with the results of auxiliary examinations to clarify the diagnosis, among which CT, magnetic resonance imaging and splenic portal vein angiography are more helpful for the diagnosis of this disease.
Treatment
1. General treatment
Pay attention to rest, strengthen nutrition, consume high protein, high carbohydrate and low fat diet, avoid using hepatotoxic drugs, and quit drinking.
2. Non-surgical treatment
(1) Urokinase or streptokinase thrombolytic therapy can be tried in the acute stage of portal vein thrombosis.
(2) Use growth inhibitors, propranolol, etc. to reduce portal pressure.
(3) For the occurrence of esophageal – fundic varices rupture bleeding can use vasopressin and three-lumen double-bladder tube compression to stop bleeding.
3. Endoscopic treatment
Endoscopic ligation of varicose veins in the lower esophagus and gastric fundus, or endoscopic injection of sclerosing agent.
4. Interventional therapy
The main purpose is to embolize part of the splenic artery through interventional methods to reduce the blood flow of the splenic vein, lower the pressure of the portal vein, and control the symptoms of hypersplenism to a certain extent.