PORTAL HYPERTENSION: MODERN DIAGNOSIS AND TREATMENT

Аннотация

Portal hypertension is a common and serious complication of chronic liver disease, particularly cirrhosis. It is defined by an increase in the pressure within the portal venous system and is responsible for significant morbidity and mortality due to complications such as variceal bleeding, ascites, and hepatic encephalopathy. With advancements indiagnostic imaging and therapeutic interventions, the management of portal hypertension has significantly improved in recent years. This article explores the pathophysiology, current diagnostic modalities, and state-of-the-art treatment options for portal hypertension, highlighting recent innovationsand clinical strategies. Key words:portal hypertension, treatment, diagnosis, bloodvassels. Introduction: Portal hypertension (PH) is characterized by elevated blood pressure in the portal vein, typically resulting from resistance to blood flow through the liver. This condition most frequently arises due to cirrhosis, in which normal liver tissue is replaced with fibrotic tissue that disrupts normal vascular architecture. Clinically significant portal hypertension is defined as a hepatic venous pressure gradient (HVPG) of 10 mmHg or more. It is a key driver of life-threatening complications in liver disease, and timely intervention is essential for patient survival. Pathophysiology of Portal Hypertension: Portal hypertension develops due to a combination of increased vascular resistance within the liver and increased splanchnic blood flow. In cirrhosis, thearchitecture of the liver is distorted by fibrosis and regenerative nodules, which increase intrahepatic vascular resistance. At the same time, vasodilators such as nitric oxide lead to dilation of splanchnic arteries, increasing blood flow into the portal system and compoundingthe hypertension. Collateral blood vessels may form to divert blood from the high-pressure portal system to the systemic circulation. These vessels are often fragile and located in areas such as the esophagus and stomach, where they form varices that are prone torupture and bleeding. Portal hypertension is a condition defined by an abnormal elevation of blood pressure within the portal venous system, typically when the hepatic venous pressure gradient (HVPG) exceeds 5 mmHg. Clinically significant portal hypertension (CSPH) is defined at ≥10–12 mmHgand iscommonly seen inchronic liver diseases, particularly cirrhosis. Understanding the pathophysiology involves identifying the site of increased resistance, the mechanisms involved, and systemic changes that result from sustained portal pressure elevation. Portal Venous System Overview: The portal venous system drains blood from the gastrointestinal tract, spleen, pancreas, and gallbladder into the liver. The portal vein is formed bythe confluence ofthe superior mesenteric vein and thesplenic vein. Normally, the portal pressure ranges between 5–10 mmHg. When this pressure increases beyond normal, portal hypertension develops. 98,7:ROTCAFTCAPMI .SECNEICSLACIDEM,5202,yaM,5emuloV gro.srehsilbupcimedaca.www These factors make blood flow through the liver more difficult, raising pressure upstream in theportal vein. Increased PortalBlood Inflow  Due to splanchnic arterial vasodilation in response to portal hypertension and liver dysfunction.  Mediated by nitric oxide (NO), carbon monoxide, glucagon, and vascular endothelial growth factor (VEGF).  This vasodilation causes hyperdynamic circulation — high cardiac output, low systemicvascular resistance. Increased blood volume delivered to the portal vein exacerbates the already elevated pressure.Clinical Manifestations: The clinical manifestations of portal hypertension depend onitsseverity and underlying cause. Common features include:  Splenomegaly: Enlargement ofthe spleen due tocongestion.  Ascites: Accumulation offluid intheperitoneal cavity.  Esophageal and gastricvarices: Fragile veins proneto bleeding.  Caputmedusae: Dilated periumbilicalveins visibleontheabdominal wall.  Hepatic encephalopathy: Cognitive dysfunction due to the accumulation of toxins notcleared bytheliver.  Thrombocytopenia and anemia: Resulting from splenicsequestration andblood loss. Non-Invasive Diagnostics Ultrasound with Doppler is typically the first-line diagnostic tool. It allows for visualization of portal vein flow, measurement of portal vein diameter, and detection of thrombosis. Transient elastography (FibroScan) is widely used to assess liver stiffness, indirectly reflecting portal pressure. CT and MRI provide more detailed imaging of the liver and vasculature. They are particularly useful in identifying collateral vessels and evaluating the presence of hepatocellular carcinoma. Endoscopic Evaluation: Esophagogastroduodenoscopy (EGD) remains the gold standard for the detection of varices. It allows direct visualization and classification of varices, enabling appropriate prophylactic or therapeutic interventions. Invasive Measurement:Hepatic venous pressure gradie