A portacaval shunt is a form of high blood pressure treatment that involves linking the liver's blood supply with the vein that draws blood from the lower part of the body. The surgery is considered major, and is conducted to redirect blood flow around the liver. Also known as a portal caval shunt, the operation is performed on patients with portal hypertension — present when blood pressure is high in the liver — that is most commonly caused by cirrhosis or hepatitis B or C.
During a portacaval shunt procedure, a large incision is made in the abdomen. The portal vein, from which the liver receives 75% of its blood supply, is attached to the major vein that drains blood from the lower portion of the body, the inferior vena cava. This encourages the blood to flow around the liver instead of through it, greatly reducing blood pressure in the region and safeguarding against broken veins and internal bleeding in the liver.
It is essential for healthy body function that blood flow smoothly through the liver. In individuals with cirrhosis and hepatitis B and C, the liver is severely damaged and proper blood flow is inhibited. A portacaval shunt procedure helps blood move more efficiently through the area and back up to the heart.
Portacaval shunt operations have commonly been replaced by other medical treatments, namely transjugular intrahepatic portosystemic shunting, or TIPS. TIPS is not an operation. A radiologist utilizes an x-ray machine to guide a medical shunt into the veins of the liver, which achieves the same end as a portacaval shunt: diversion of blood flow around the affected organ. It is generally performed under local anesthesia. Patients who undergo portacaval shunting have typically already tried the TIPS procedure with unsuccessful results.
The best candidates for a portacaval shunt are those who have first had a TIPS procedure which yielded an undesirable outcome. Ideal candidates usually have a chronic, progressive liver disease that requires surgery in order to extend life expectancy. Any type of serious liver damage, however, poses the risk of complications after surgery.
There are a variety of tests that can be conducted to see if an individual stands to benefit from a portacaval shunt. Blood tests and liver biopsies can find out the approximate extent of damage to the liver. Tests that determine liver functions might also be able to illustrate the need for a portacaval shunt.