TIPS

TIPS is an abbreviation of a long and incomprehensible (for laymen) term transjugular intrahepatic portosystemic shunt.

Indications

TIPS is of great importance in the treatment of large esophageal varices that occur in liver cirrhosis accompanied with portal hypertension. The mechanism of their formation is simple.  Normally, the blood from our digestive tract flows through the portal vein into the liver, where the portal vein breaks up into small venules. The nearby liver cells use these venules for uptake of nutrients and toxic compounds absorbed from the gut. Nutrients are used for body metabolism and toxic products are deactivated. The tiny blood vessels then begin to converge to larger hepatic veins that open into the inferior vena cava.

 

When the liver is affected by cirrhosis (usually due to chronic alcoholism), the blood flow through the liver tissue may be impaired. The blood accumulates in the portal vein and can not flow through the liver. This situation is known as the portal hypertension. However, there are some emergency connectors between the portal vein and inferior vena cava. The clinically most important connectors are veins located in the wall of the esophagus. Unfortunately, these connecting veins are unable to handle larger amount of blood. They expand and protrude into the esophageal cavity, forming so-called esophageal varices. These varices can perforate and cause life-threatening bleeding. The TIPS serves to restore the blood flow through the cirrhotic liver and prevent the excessive blood flow through the connector veins.

 

Note: TIPS may be also used to treat ascites, which occurs due to portal hypertension, when the ascites is resistant to pharmacotherapy.

Principle

The basic mechanism of TIPS is essentially primitive. Very simply put, the TIPS is a hollow tube, which is inserted into the inferior vena cava and through the liver tissue into the portal vein. In the liver tissue, the TIPS creates a sort of a tunnel, which allows the blood to flow freely from the portal vein into the inferior vena cava, without coming into contact with the cirrhotic liver tissue. However, this fact also means serious complications.

 

TIPS
Schema - established TIPS tube connects the portal vein to the liver veins
and helping blood flow to the vena cava (blue arrows).

 

Advantages

If the TIPS stays operable and does not occlude by local blood clots, the patient is saved from the portal hypertension and its complications (esophageal varices and ascites). The blood flows again freely through the liver.

Disadvantages

The TIPS prevents sudden death from esophageal hemorrhage, but it does not improve the overall prognosis of cirrhotic patients. There are two major complications of TIPS.

 

First problem is possible overload of the right side of the heart. Under normal circumstances, a healthy liver puts certain amount of resistance to the blood flow (yet much lower resistance than the cirrhotic liver). In TIPS, the resistance is minimal and too large amount of blood enters the vena cava, which opens directly into the right heart atrium. This may cause overload of the heart and heart failure.

 

Hepatic encephalopathy is another serious complication of TIPS. As I wrote above, the portal blood coming from the intestines carries a number of toxic substances and also nitrogen compounds produced by intestinal bacteria. Under normal circumstances, the liver cells pick up these harmful substances and detoxify them. However, the TIPS significantly decreases the close contact between the blood and the liver cells. All these pollutant go through the liver and flow directly to the heart and further to the brain. Brain gets damaged, which manifests as the hepatic encephalopathy - personality changes, confusion, dementia, flapping tremor, memory impairment and eventually death. More information about this condition, its prevention and management can be found in the related article.

 

For these reasons, the survival time of a patient with TIPS is approximately only several years. The TIPS simply prevents rapid death by esophageal bleeding, but it is not a terminal solution. Only a liver transplant could resolve the situation.