SHUNT SURGERY FOR PORTAL HYPERTENSION

Patient Education Material

Portal Hypertension

It is an increase in the blood pressure in the portal vein, which carries the blood from the bowel and spleen to the liver. The pressure in the portal vein may rise because there is a blockage, such as a blood clot, or because the resistance in the liver is increased because of scarring (fibrosis) or cirrhosis. As a result, the pressure in the portal vein rises. This is known as portal hypertension.

Bleeding oesophageal varices:

As the blood tries to find another way back to the heart, new blood vessels open up. Among these vessels are those that run along the wall under the lining of the upper part of the stomach and the lower end of the esophagus (food pipe). These veins protrude into the gullet and the stomach and can bleed. The dilated veins in the gullet are known as varices. Bleeding may be a gentle ooze in which case anemia is the commonest symptom. Sometimes there can be a major bleed; a person may have a hemorrhage and either vomit blood or passes blood through their bowels. This blood may appear to be black since it is often changed as it passes through the body.

Details:

Oesophageal varices represent a significant complication of cirrhosis and some other types of liver damage.

There are many causes of cirrhosis, hepatitis C (HCV) being the most common in Pakistan. Others include hepatitis B (HBV), non-alcoholic fatty liver disease (NASH),  autoimmune hepatitis,  primary biliary cirrhosis,  primary sclerosing cholangitis and some metabolic diseases.

Portal hypertension may also arise as a result of a parasitic disease, which is common in the Middle East and parts of South America. Other conditions including clotting disorders and pancreatic disease can lead to portal hypertension.

DIAGNOSIS OF VARICES:

Unless they bleed, varices do not produce any complications or symptoms. The only way they can be detected is by a process called endoscopy. During endoscopy a small flexible tube is put into the gullet and the endoscopist can see not only where the varices are present but also their size. Not everyone with cirrhosis has varices and not everyone with varices will bleed. In general, small varices rarely bleed and bigger ones may bleed. Small varices however, may well develop into large varices over time.

For those people who have varices and are likely to bleed, treatment with drugs can sometimes reduce the risk of bleeding and reduce the severity of any bleed should it occur. The drug most commonly used is propranolol. As with all drugs, not everyone is suitable and some people have side-effects. Alternative methods may sometimes be used for those who are at risk of bleeding.

TREATMENT OF VARICES:

Current treatments do allow for early identification of those people who are at risk of variceal bleeding, and treatments can greatly reduce the risk and severity of the bleeds. For those who have bleeding oesophageal varices, this is a medical emergency but early treatment is usually highly effective. There are a variety of approaches to treat bleeding varices and the treatment used will depend on the overall condition of the individual.

Propranolol is used both for the prevention of bleeding and also in those people who have bled. It may be used in the prevention of re-bleeding.

Treatment of bleeding varices

If you vomit blood or pass blood with your stools this is a medical emergency and you should go to hospital immediately. You should tell the doctors and nurses that you have liver disease and bleeding, since early treatment will reduce the consequences.

Initial treatment is to replace the fluid and then to identify and correct the cause of bleeding. Not everyone who has varices and who bleeds will be bleeding from varices. They may be bleeding from another area in the digestive tract.

A number of treatment options are available for the treatment and prevention of bleeding.

Drugs

Several drugs are useful in the treatment of the variceal bleed. These drugs, such as glypressin or octreotide, are given by injection.

Endoscopic techniques

There are two treatments that can be given at endoscopy to treat and prevent bleeding. These are:

  • Banding– with banding techniques a single vein (the varix) is sucked into a ring at the end of the endoscope. A small band is placed around the base of the varix. After one or two days this will result in the formation of a clot which will control the bleeding.
  • Injection scleropathy – this is a sclerosant (special chemical) material injected into the veins of the gullet. It is done after you have been given some sedation and a camera (endoscope) has been passed into your gullet. A fine flexible needle is passed through the endoscope and used to inject the sclerosant material into the oesophageal veins or the adjacent veins. These injections cause clotting and will also stimulate some scarring to reduce the recurrence of varices.

There are additional procedures that can be used in an emergency to stop active bleeding from the stomach and gullet. Please see Emergency Procedures for more information.

Shunting procedures

Shunting operations involve joining two veins. Shunts may either be done surgically or by the radiologist. In a surgical shunt, the blood that would normally go into the portal vein is diverted into another vein. There are several types of shunts available. This process involves a major operation.

TIPPS

TIPSS stands for transjugular intrahepatic portal systemic shunt. This technique is usually done by a radiologist but other clinicians also carry this out. In this procedure a metal tube is passed across the liver to allow the blood in the portal vein to go straight into the hepatic vein and so bypass the high resistance of the liver. This procedure is usually done in the Radiology Department and may take several hours.

Both types of shunt procedure are very effective in lowering portal pressure but they do have complications.

One of these complications is encephalopathy whereby the person may get a little bit drowsy, confused or in rare cases even comatosed. This is because the blood usually clears toxins from the bowel and if these toxins bypass the liver they can affect the electrical activity of the brain.

Portal vein thrombosis

Portal vein thrombosis (PVT) is the blockage of the portal vein with blood clots. In fact some believe that there is 1% lifetime risk of PVT in general populationThe diagnosis can now be readily established by using ultrasound scan or CT or scans.

There are various causes of PVT, but whatever the cause, the sequence of events are very serious. Patients may present with severe bleeding from esophageal or gastric varices. The two main types of PVT are acute and chronic.

Treatment of portal vein thrombosis (PVT)

There are various forms of treatment modalities for PVT, these include medical and surgical.

Medical treatment

The mainstay of treatment is to minimize portal hypertension and to avoid progression of thrombosis (clot in the portal vein) by;

1-Anticoagulation (blood thinning medications). Spontaneous recovery with re-canalization of the portal vein can be achieved in near half of the patients with anticoagulation.

2-Endoscopic intervention (banding or sclerotherapy) for bleeding varices

3-Drug therapy (propranolol) to reduce portal hypertension

Surgical shunts

The patients that do not respond to the medical therapy may require surgical intervention if they suffer from persistent complications of portal hypertension. Variceal bleed is common and disastrous complication

Surgical options for PVT include liver transplant and portosystemic shunting. The choice of procedure depends upon patients overall condition and liver status. Liver transplant is only considered for patients who has severe scarring (cirrhosis) of the liver. Those patient whose liver function is normal; they are good candidate for surgical shunts.

The shunting procedures available are;

  • Splenorenal shunt
  • Mesocaval shunt
  • Portocaval shunt

It is believed that the shunt operation are very effective in controlling the risk of bleeding in long term.