Portal Hypertension

How portal hypertension develops

About 75% of the liver's blood supply arrives through the portal vein. In cirrhosis, scar tissue and changes in liver blood vessels increase resistance to flow. Pressure rises in the portal vein. The body responds by opening collateral veins that bypass the liver, connecting to the general circulation at:

• the lower esophagus and upper stomach: esophageal and gastric varices
• the rectum: rectal varices
• the belly wall: visible veins around the navel

At the same time, blood vessels in the gut widen, increasing flow into the portal system and worsening pressure.

Causes

Cirrhosis accounts for the large majority of cases in the US and Europe.

Symptoms and complications

Portal hypertension itself causes no symptoms. Its complications do:

• variceal bleeding: vomiting blood or passing black or bloody stools. It is a life-threatening emergency
• ascites: fluid buildup causing a swollen belly, weight gain, breathlessness and ankle swelling
• spontaneous bacterial peritonitis: infection of ascites fluid, with fever, belly pain or confusion
• hepatic encephalopathy: confusion, sleepiness, personality change and a flapping tremor, as toxins bypass the liver
• splenomegaly: an enlarged spleen that traps platelets, causing low platelet counts and easy bruising
• hepatorenal syndrome: kidney failure in advanced liver disease
• hepatopulmonary syndrome and portopulmonary hypertension, affecting oxygen levels and the lungs

Diagnosis

• blood tests: low platelet count is often the first clue; liver function, albumin, INR
• ultrasound with Doppler: shows liver texture, spleen size, ascites, portal vein flow and clots
• transient elastography (FibroScan): measures liver stiffness; together with platelet count, it identifies people likely to have clinically significant portal hypertension and those who can safely skip screening endoscopy (Baveno criteria)
• upper endoscopy: finds varices and assesses their bleeding risk
• hepatic venous pressure gradient (HVPG): a direct measurement through a catheter, mainly used in specialist centers; 10 mmHg or higher defines clinically significant portal hypertension
• CT or MRI for vessels and liver tumors

Treatment

Treat the liver disease

Stopping alcohol, treating hepatitis B or C, weight loss for fatty liver disease, and managing other causes can lower portal pressure and prevent complications.

Preventing variceal bleeding

• non-selective beta-blockers (carvedilol, propranolol, nadolol) lower portal pressure and reduce the risk of first bleeding and other decompensation
• endoscopic variceal ligation (banding): small rubber bands placed on varices, for those with large varices who cannot take beta-blockers or after a bleed

Treating acute variceal bleeding

Hospital emergency care: blood transfusion, medicines such as octreotide to lower portal pressure, antibiotics to prevent infection, urgent endoscopic banding, and sometimes a balloon tube or an emergency TIPS.

Ascites

• a low-sodium diet (about 2 g sodium a day)
• diuretics (spironolactone and furosemide)
• large-volume paracentesis (draining fluid with a needle), with albumin infusion
• avoiding NSAIDs

TIPS

Transjugular intrahepatic portosystemic shunt (TIPS) creates a channel within the liver between the portal vein and a hepatic vein, placed by a radiologist through the neck. It lowers portal pressure effectively for refractory ascites or recurrent bleeding but can worsen encephalopathy.

Encephalopathy

Lactulose and rifaximin reduce toxin production in the gut.

Liver transplant

The definitive treatment for portal hypertension due to advanced cirrhosis.

Outlook

Outcome depends on how severe the liver disease is and whether complications have developed. Once complications such as bleeding, ascites or encephalopathy appear ("decompensated cirrhosis"), survival falls, and transplant evaluation is considered. Treating the cause, for example achieving abstinence from alcohol or curing hepatitis C, can improve outlook substantially.

Frequently asked questions

What is portal hypertension?

It is high blood pressure in the portal vein, which carries blood from the intestines and spleen to the liver. It is most often caused by cirrhosis and leads to complications such as varices, ascites and an enlarged spleen.

What are the symptoms of portal hypertension?

Portal hypertension itself is silent. Symptoms come from complications: vomiting blood or black stools from bleeding varices, a swollen belly from ascites, confusion from hepatic encephalopathy, and easy bruising from low platelets.

How is portal hypertension treated?

Treatment includes treating the liver disease, beta-blockers to lower pressure, banding of varices, diuretics and drainage for ascites, lactulose for encephalopathy, and TIPS or liver transplant in advanced cases.

Can portal hypertension be reversed?

It can improve if the underlying cause is treated early, for example stopping alcohol or curing hepatitis C, which can reduce liver scarring and pressure. In advanced cirrhosis, it is usually managed rather than reversed, and liver transplant may be needed.