Portal Hypertension

Portal hypertension is a clinical syndrome defined by a pathological increase in the hydrostatic pressure within the portal venous system. The hemodynamic criterion is a hepatic venous pressure gradient (HVPG) greater than 5 mmHg.

NOTE: Clinically significant portal hypertension (which is what is typically asked about), associated with variceal development and decompensation, is typically defined as an HVPG ≥10 mmHg. It is a consequence of increased resistance to portal blood flow, increased portal venous inflow, or both.

General Information & Epidemiology

Portal hypertension is the primary driver of morbidity and mortality in chronic liver disease. Its complications (variceal hemorrhage, ascites, hepatic encephalopathy, and hepatorenal syndrome) define the decompensated phase of cirrhosis.

Most Common Causes & Approximate Prevalence:

• Cirrhosis: Accounts for >90% of cases in Western countries. Etiologies include alcohol-associated liver disease, hepatitis C and B, liver fibrosis (Wilsons disease, hemochromatosis) and non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH).
• Non-Cirrhotic Portal Hypertension:
  • Extrahepatic Portal Vein Obstruction (EHPVO): A leading cause in children and younger adults in developing nations; less common in adults (∼5-10% of non-cirrhotic cases).
  • Schistosomiasis: A major global cause, especially in endemic regions (e.g., parts of Africa, South America, Asia).
  • Idiopathic Portal Hypertension: Rare.

• Pre-sinusoidal Causes: Myeloproliferative disorders, sarcoidosis, Budd-Chiari syndrome, congenital hepatic fibrosis.

The sinusoidal resistance is the most often.

Pathological consequences

Portal vein synthopy.

Splenomegaly

Splenomegaly in PH is caused by higher blood pressure in lienal vein. If the progress of PH is rapid, it can even cause intraabdominal bleeding (rupture of spleen), but it is quite infrequent.

Esophageal varices

Esophageal varices.

Gastric varices in patient with presinusoidal portal hypertension (left portal vein trombosis).

There are junctions between portal vein and superior vena cava (portocaval anastomoses between gastric veins and esophageal veins). The esophageal veins are localized in esophageal submucosis. If the high blood pressure in portal vein expands here (the vascular ressistance is lower than in liver), the consequence are esophageal varices, which are dangerous because of possible bleeding. Esophageal varices bleeding is quite often complication in patients with liver cirrhosis (30–60% of them).

 For more information see Esophageal varices.

Ascites

Ascites is accumulation of noninflammatory fluid in peritoneal cavity. Formation of ascites is based on natrium retention and vascular resistance in liver. The fluid with albumin gets from liver sinusoides to interstitial space in liver because of higher portal pressure. The liver lymphatic veins can drain away just a part of this fluid. The rest of this fluid gets out the liver to peritoneal cavity like ascites.

 For more information see Ascites.

Blood congestion in gut

Blood congestion in portal vein expands to vena lienalis and intestinal veins (via mesenterical vein). The consequence is mucosal hyperemia of small intestine, which can cause malabsorption.

Hypercirculation

Hypercirculation is caused by opened portocaval anastomoses. The vascular ressistance here is lower than the vascular resistance in liver. It causes, that these junctions are not only opend, but even the blood flow here can be pretty high. The portal blood (with substances obtained in small intestine) can "flow round the liver" to superior or inferior vena cava. The blood circulation is more rapid than it should be (it is hypercirculation).

Hepatic encephalopathy

Hepatic encephalopathy is multifactorial neuropsychiatric syndrome. It is probably caused by decreased liver metabolism (cirrhosis…) and hypercirculation (a part of the portal blood flows round the liver via portocaval anastomoses). Then the blood in system circulation contains higher level of toxins (from gut) and ammonia (produced by bacteries in gut). This encephalopathy is characterized by disturbances in consciousness and behavior, personality changes and neurological symptomatology (flapping tremor).

Diagnostic

1. Clinical Suspicion: Based on stigmata of chronic liver disease or complications (ascites, variceal bleeding, splenomegaly).
2. Non-Invasive Indicators: Ultrasound with Doppler is first-line. Findings include:
   • Portal vein diameter >13 mm, decreased/absent portal flow, hepatofugal flow (hepatofugal flow is the reversal of blood flow away from the liver within the portal vein, indicating severe portal hypertension).
   • Portosystemic collaterals (e.g., recanalized paraumbilical vein, splenorenal shunt).
   • Splenomegaly, ascites.
   • Cavernous transformation of the portal vein (in EHPVO).
3. Direct Hemodynamic Measurement:
   • Hepatic Venous Pressure Gradient (HVPG): The gold standard. Measured via catheterization of the hepatic vein. HVPG = Wedged Hepatic Venous Pressure (WHVP) - Free Hepatic Venous Pressure (FHVP). It directly reflects sinusoidal pressure. Key: HVPG is elevated in cirrhosis, normal in pre-hepatic (EHPVO) and many pre-sinusoidal causes.
4. Endoscopic Diagnosis: Esophagogastroduodenoscopy (EGD) is mandatory to screen for and grade esophageal and gastric varices.
5. Etiologic Work-up: Liver biopsy (for cirrhosis), serology for viral hepatitis, thrombophilia screen (for EHPVO), schistosome serology/stool studies.

Summary:

• Physical examination: caput medusae - dilated subcutaneous veins of abdomen, palmar erythema,
• USG: splenomegalia, hepatic venous pressure gradient (HVPG, normal is 3–4 mm Hg), ascites,
• Gastroscopy: esophageal varices and their bleeding,
• Labs: elevated liver markers (ALT, AST), koagulopathy (INR > 1,5), decrease of albumin,
• Hematology: decrease in platelets (because of splenomegaly).

Therapy

Therapy includes therapy of PH itself and therapy of complication (esophageal varices and its bleeding, encephalopaty, ascites…), therapy of liver cirrhosis, liver transplantation.

A. Pharmacologic (First-line for prevention and acute bleeding):

• Non-selective Beta-Blockers (NSBBs: propranolol, nadolol):
  • Mechanism: Dual blockade of β1 and β2 receptors. β1-blockade reduces cardiac output, decreasing portal inflow. β2-blockade induces unopposed α-adrenergic activity, causing splanchnic vasoconstriction, further reducing portal inflow. Goal: reduce HVPG by >20% or to <12 mmHg.
  • Optimal heart rate decrease is 25% of heart rate or heart rate 55/min.
• Vasoactive Drugs (for acute variceal bleed): Somatostatin, Octreotide, Terlipressin.
  • Mechanism: Cause splanchnic vasoconstriction via inhibition of vasodilatory peptides (e.g., glucagon), rapidly reducing portal blood flow and pressure.

B. Endoscopic Therapy:

• Variceal Band Ligation (EBL):
  • Mechanism: Physical obliteration of submucosal varices via rubber band placement, leading to thrombosis and fibrosis. Used for primary and secondary prophylaxis.
• Cyanoacrylate Injection (for gastric varices):
  • Mechanism: Tissue adhesive that rapidly polymerizes on contact with blood, achieving immediate hemostasis by occluding the varix.

C. Radiologic Intervention:

• Transjugular Intrahepatic Portosystemic Shunt (TIPS):
  

  TIPS.
  • Transjugular Intrahepatic Portosystemic Shunt is artificial junction between portal vein and inferior vena cava. This shunt is introduced via vena jugularis interna. This method should be used in patients with complicated pharmacoresistant portal hypertension (often esophageal varices bleeding).. This percutaneous method replaced surgical shunt.
  • Mechanism: Creates a low-resistance conduit between the hepatic vein and an intrahepatic portal branch, decompressing the portal system by shunting blood directly into the systemic circulation. Dramatically reduces portal pressure but diverts blood from the liver, risking hepatic encephalopathy

D. Surgical:

• Portosystemic Shunt Surgery (e.g., distal splenorenal shunt): Now largely superseded by TIPS except in specific circumstances (e.g., EHPVO with good surgical anatomy).
• Liver Transplantation: The definitive treatment for portal hypertension due to cirrhosis, addressing the underlying liver disease.

Links

Related articles

• Cirrhosis
• Esophageal Varices
• Ascites

External links

• Gastric varices – images