Shunt Surgical Procedures

Shunt surgical procedures are used to improve the flow of blood in veins connected to the liver, the esophagus, and other parts of the body, to stop bleeding and relieve pressure in these blood vessels, and to correct swollen veins.

What Is A Portal Systemic Shunt?

Introduced in 1945, the portal shunt (portal systemic shunt) was the first definitive form of therapy used for patients who had bled from swollen (varicose) veins in the gullet (esophageal varices). It involves the surgical joining of two veins, the portal vein and the inferior vena cava, to relieve pressure in the portal vein that carries blood into the liver.

Who Qualifies For This Procedure?

Elective portal shunt surgery is performed in only a relatively small number of patients who bleed from esophageal varices. About one-fourth have such severe, uncontrollable bleeding that they either die quickly or require emergency surgery. The mortality associated with portal shunts performed as emergencies is even higher at about 20-50%. Another one fourth are considered poor surgical risks. Suitable patients for portal shunts are those who are relatively good candidates for major surgery.

Is This Procedure Still Performed?

The shunt operation virtually eliminated recurrent hemorrhage from varices, but its popularity waned in the 1970's for two major reasons. One was the frequency of encephalopathy (dysfunction of the brain) as a complication. The other was the failure of controlled clinical trials to establish a statistically significant advantage in survival for patients treated with shunts over those treated with nonsurgical therapy. The failure of portal shunts to enhance survival reflected the associated complications of encephalopathy and post shunt failure.

Distal Splenorenal Shunt (DSRS)

This operation was devised to preserve the flow of blood through the portal vein to the liver while decompressing varices in the stomach and esophagus by means of the spleen and splenic vein joined to the left kidney vein. Studies comparing portal systematic shunts with DSRS found similar rates of overall mortality and cumulative survival. DSRS had a higher operative mortality but a lower rate of encephalopathy afterwards. Also, patients with alcoholic cirrhosis do poorly with DSRS compared to nonalcoholic cirrhotic patients.

A leading question among liver specialists during the past decade has been the relative value of DSRS and using drugs to narrow the swollen veins (scleropathy drug therapy) in preventing recurrent variceal bleeding. The major merit of sclerotherapy is that it is relatively easy to apply and can be administered at many primary care hospitals. Most physicians will use a flexible endoscope in order to inject diluted mixtures of sclerosing solutions into the esophageal varices. A study at Emory University supports the initial management of patients with cirrhosis and variceal bleeding by endoscopic sclerotherapy. However, it also showed that the occurrence of gastric (stomach) variceal bleeding, hypertensive gastritis bleeding, or repeated esophageal variceal bleeding should be recognized early as sclerotherapy failures and treated surgically. In this combination, initial sclerotherapy and selective shunt surgery may significantly improve survival in patients with variceal bleeding.

Transjugular Intrahepatic Portal-Systemic Shunt (TIPS)

An important recent advantage has been the development of the transjugular intrahepatic portal-systemic shunt (TIPS). TIPS is performed by radiologists using only a local anesthetic and a sedative. A long needle is inserted via the jugular vein in the neck, advanced into a hepatic vein and then into a large branch of the portal vein in the liver. Using an inflatable balloon-tipped catheter tube, the section between the portal vein branch and the hepatic vein is widened and then kept open (stented) with a cylindrical wire-mesh stent.

What Are The Advantages and Dangers of TIPS?

The major advantages of TIPS are that it dispenses with the need for a general anesthetic and a major surgical procedure, both of which are often poorly tolerated by patients with cirrhosis. Another advantage of TIPS is that it reduces ascites (accumulation of fluid in the abdomen) while the DSRS does not. It has been used successfully to treat severe ascites that no longer respond to the use of drugs to reduce the amount of fluid (diuretic). TIPS is a valuable innovation, but it is not without its hazards. Although the direct mortality from TIPS complications is relatively low ( less than 5%), this is true only in the hands of experienced radiologists in specialized centers. Approximately one quarter of patients develop encephalopathy after TIPS, and these shunts frequently narrow or block up, requiring additional interventional procedures. In the setting of life-threatening bleeding that cannot be controlled by sclerotherapy, TIPS is probably the ideal shunt procedure if it is readily available. In patients with portal hypertension who have failed treatment with sclerotherapy and are candidates for liver transplantation in the near future, TIPS is not the preferred type of shunt. This reflects the fact that the presence of a surgical shunt makes transplant surgery more difficult and may result in an increased risk of complications and death following liver transplantation. In patients who have recurrent bleeding in spite of sclerotherapy and whose liver function is good, DSRS may be preferable in the elective or non-emergency setting. Appropriate clinical comparisons between TIPS, DSRS, and sclerotherapy are not yet available and will help to further clarify the place of TIPS in the management of variceal bleeding.