Portal Hypertension

The portal vein, a major vein in the abdomen, collects nutrient- rich blood from the intestines and delivers it to the liver to nourish it, where it is purified for our body to use. Portal hypertension is high blood pressure of the portal vein. Unfortunately, there is no simple way or test to show if a person has portal hypertension. We cannot use a bloodpressure cuff like we can on an arm to measure "whole body" hypertension. Doctors become aware of portal hypertension when its signs and symptoms are first noticed. The most common cause of portal hypertension is cirrhosis, which refers to the "hardening" of the liver because of scar tissue. The other primary cause of portal hypertension is due to clots which narrow or block blood flow through the veins to and from the liver. Portal hypertension is fairly uncommon, but when it occurs, it most often happens in older adults and may result in death, if untreated.

What Happens?
Like other organs, the liver needs oxygen and nutrients to function, which it receives from the portal vein. After the oxygen-rich and nutrient-rich blood passes through the liver, it flows into the hepatic veins (Figure 1) and on into the inferior vena cava, which takes it back to the heart. Blocked or reduced blood flow at any point of this process will result in increased pressure inside the portal vein. When this occurs, blood is detoured into other smaller veins that ultimately allow blood to flow back to the heart. However, these smaller veins can enlarge and form varices (varicose or dilated veins). Varices (pronounced var-uh-seez) can rupture or burst, especially where the esophagus and the stomach join. Bleeding from varices can be massive, causing patients to vomit blood, which is a major cause of death in patients with portal hypertension.

Blood may also be detoured through the veins along the rectum, the lowest portion of the large intestine (colon), causing them to enlarge. Enlarged veins along the rectum are called internal hemorrhoids, which can rupture and result in massive bleeding from the rectum and anus.

Another symptom of portal hypertension is ascites (uh-sahy-teez), the collection of large amounts of fluid in the abdomen. Ascites can lead to early sensations of being full when eating, resulting in malnutrition. People with ascites often have a harder time being active because of the weight of the fluid and the large size of their abdomen. Someone with massive ascites will have a protruding or swollen abdomen, often with thin legs and arms, due to muscle loss because of liver disease and malnutrition.

Ascites can cause the kidneys to fail. Urgent steps must be taken to drain the ascites and to monitor the kidneys and liver. Unless the liver function is corrected and the kidneys recover, approximately half of these patients die within a few weeks.

Treatments:
Medical treatment of portal hypertension includes beta-blockers. This class of drugs helps to decrease blood flow into the portal-vein system and to decrease the pressure. Beta-blockers also reduce the risk of bleeding from varices.

Minimally invasive procedures such as endoscopic variceal sclerotherapy (EVS), which involves the injection of a solution to seal the bleeding, and endoscopic variceal banding (EVB), which is the placement of a band from inside the esophagus to seal the bleeding, are used to stop bleeding from varices.

A temporary solution for portal hypertension is a procedure known as transjugular intrahepatic portasystem shunt (TIPS) (Figure 2). This procedure inserts a stent (a hollow wire tube) between the right hepatic vein (the vein that collects blood from the right side of the liver) and the right branch of the portal vein. The stent passes through the liver to connect these two vascular structures. With TIPS, blood moves through the stent and bypasses the liver. This procedure has both advantages and disadvantages. TIPS reduces portal- vein pressure and bleeding from varices. However, TIPS is associated with an increased risk of brain dysfunction because the brain does not get all the nutrients usually provided from passing through the liver. Additionally, there is no proof that someone lives longer after this procedure. TIPS is also expensive and has a high failure rate within one year because the stent often becomes narrowed or blocked.

Another treatment of portal hypertension is surgical shunting, a more invasive procedure than TIPS. However, some believe that surgical shunts, particularly in certain locations, improve long-term survival with portal hypertension. The only way to fully cure portal hypertension is with a liver transplant, which is expensive and afterward the patient needs lifelong medical attention. With liver transplantation continuing to be a difficult solution, a better understanding of portal hypertension is required, along with earlier diagnosis and management of the disease. Then, patients with portal hypertension can have a better and longer life.

Authors: Sam Al-Saadi, MD, Amy Collins, BS, Jennifer Cooper, BS, Carl Bowers, RN, Eleanor Justen, MD, Alexander Rosemurgy, MD, FACS Department of Surgery, University of South Florida, Tampa.