Portacaval shunt

Definition

A portacaval shunt is a treatment for high blood pressure in the liver. A connection is made between the portal vein, which supplies 75% of the liver's blood, and the inferior vena cava, the vein that drains blood from the lower two-thirds of the body.

Causes

The most common causes of liver disease resulting in portal hypertension are cirrhosis caused by alcohol abuse and viral hepatitis (hepatitis B and C). Less common causes include diseases such as hemochromatosis, primary biliary cirrhosis, (PBC), and portal vein thrombosis.

Symptoms

Patients with portal hypertension will have varices, which are swellings of veins near the esophagus and rectum caused by backup of blood in the diseased liver. Varices may bleed, leading to the vomiting of blood or blood discharge from the rectum. Patients may also have enlarged veins on the surface of the abdominal wall.

Liver diseases involving portal hypertension often also cause jaundice (a yellow tinge to the skin and eyeballs), ascites (accumulation of fluid in the abdomen), and difficulty with stopping bleeding, due to an inability of the diseased liver to make clotting factors. As the liver fails to clear toxins from the body, patients may also suffer from hepatic encephalopathy, a disorder where concentration, mental status, and memory are affected; in extreme cases, encephalopathy can lead to coma.

Exams and Tests

Many different laboratory tests are used to determine the presence and causes of liver disease.

• Liver function tests may be abnormal.
• Blood tests may detect the presence of viral hepatitis.
• Percutaneous liver biopsy may help diagnose liver disease.
• Endoscopy may be used to diagnosis esophageal varices.

Hemochromatosis, primary biliary cirrhosis, and primary sclerosing cholangitis may be diagnosed with a combination of laboratory blood tests and physical exam.

Treatment

Portacaval shunting is a major operation, requiring an abdominal incision.

Blood flow is diverted around the liver, usually by creating a connection between the portal vein and the inferior vena cava. This reduces pressure in the veins draining the liver, decreasing the dilation of variceal veins in the esophagus, which otherwise are prone to rupture and bleeding.

Portocaval shunting has largely been abandoned since the advent of TIPS (transjugular intrahepatic portosystemic shunting). This procedure does not involve an incision; rather, a catheter is placed into a large vein in the neck through which a shunt is deployed in the veins draining the liver, thus diverting blood flow around the diseased liver.

Portacaval shunting is generally reserved for patients who have failed TIPS.

Outlook (Prognosis)

Patients with liver disease have a greatly increased risk of complications after surgery, including bleeding, encephalopathy, and liver failure. The risks associated with surgery in such patients are significant. Portacaval shunting is generally a procedure used to prolong life until other measures can be taken. Patients with chronic progressive liver disease who are good candidates should be evaluated for liver transplant

Possible Complications

Complications from this procedure include bleeding, worsening of encephalopathy, and liver failure.

When to Contact a Medical Professional

Call your doctor if you experience any of the signs of liver disease, including jaundice, changes in mental status, or bleeding.

Prevention

Cessation of alcohol intake is important for all patients with liver disease, regardless of the cause. Avoiding blood product contamination (transfusion, intravenous drug use with shared needles, high-risk sexual behavior) can prevent the spread of viral hepatitis.