TIPSS (Transjugular Intrahepatic PortoSystemic Shunt)

TIPSS (Transjugular Intrahepatic PortoSystemic Shunt)


Introduction

This tells you about the procedure known as TIPSS. It explains what is involved and what the possible risks are. It is not meant to be a substitute for informed discussion between you and your doctor, but can act as a starting point for such a discussion.
If you are having the procedure performed as a pre-planned operation then you should have plenty of time to discuss the situation with the consultant radiologist and the consultant who referred you for the procedure. Your own GP may be able to give you some general advice. If you need the procedure as a relative emergency then there may be less time for discussion, but nonetheless, you should have had sufficient explanation before you sign the consent form.

What is TIPSS?

The best way of describing what TIPSS is, is to explain what the letters stand for.
T is for TRANSJUGULAR. This means that the radiologist will put a fine, hollow needle into the jugular vein in your neck while you are asleep. Through this needle he, or she, will pass a fine, thin wire in a straight line until it reaches the veins from your liver. This is much easier than you would imagine. Over this wire the radiologist will pass a fine plastic tube called a catheter, about the size of a very long piece of spaghetti.
I is for INTRAHEPATIC. The catheter that the radiologist has inserted will be passed down one of your liver veins into the liver itself. The radiologist will then take the wire out and insert a long curved needle.
PS is for PORTO-SYSTEMIC. The long needle will be pushed from your liver vein, (or SYSTEMIC vein) into your PORTAL vein, which lies close to it. It is this portal vein which has become partially blocked up by your liver disease. Because of the blockage, there is high blood pressure in this part of your circulation, and this procedure is designed to relieve this.
S is for SHUNT. Once the needle has been passed between your liver vein and the portal vein, a wire will be passed through the needle and the needle withdrawn. Over the wire the radiologist will pass a metal spring called a stent. This stent will expand to create a channel between the two veins. Blood will then flow from the high-pressure portal vein into the low-pressure liver (or systemic) vein. The high pressure in the portal vein which is causing your problem, will consequently be reduced, back towards normal.

Why do I need a TIPSS?

Normally, the nutrients in food are absorbed from the bowel, and carried back in blood vessels towards the liver. The largest of these vessels is called the portal vein. Once the nutrients reach the liver, they can be stored and then used. The liver also removes waste products. The disease in your liver is blocking the flow of blood like a dam, and is causing the blood pressure in the portal vein to rise. Because of this, you may have developed extra veins inside your abdomen, like varicose veins, which may have bled into your stomach, or your gullet. You may have vomited blood. You may also have excessive fluid inside your abdomen. Your gastro-enterologist or your surgeon will have tried other methods of stopping the bleeding, or lowering this high portal blood pressure. These probably have not worked. An open operation is possible to divert blood in the portal vein and lower the pressure, and this produces the same result as a TIPSS does. However, the open operation is considered much more dangerous than TIPSS. It is possible that you are also being considered for a liver transplant.

Who has made the decision?

The doctors in charge of your case, and the radiologist doing the TIPSS, will have discussed the situation and feel that this is the best option. However, you will also have the opportunity for your opinion to be taken into account and if, after discussion with your doctors you do not want the procedure carried out, then you can decide against it.

Who will be doing the TIPSS?

A specially trained doctor called an interventional radiologist will carry out the TIPSS. Interventional radiologists have specialist expertise in using X-ray and scanning equipment and also in interpreting the images produced. They need to look at these images while carrying out the procedure.

Where will the procedure take place?

The procedure will take place in the X-ray department in a special “screening” room which is adapted for these specialised procedures.

How do I prepare for TIPSS?

You need to be an inpatient in the hospital. You will probably be asked not to eat for several hours beforehand, although obviously if you are ill and the procedure is being carried out as an emergency you may not be eating anyway. You may receive a sedative to relieve anxiety, as well as an antibiotic. If you have any allergies you must let your doctor know. If you have previously reacted to intravenous contrast medium, the dye used for kidney X-rays and CT scanning, then you must also tell your doctor about this.

What actually happens during a TIPSS?

You will be taken down to the X-ray department on a trolley. You need to have a needle put into a vein in your arm or hand, so that you can have intravenous sedatives or painkillers. Once in place, this needle does not hurt. In the X-ray department the anaesthetist, who you will have met already, will put you to sleep. However, if it has been decided not to use a general anaesthetic, then do not worry. An anaesthetist, or the radiologist and other trained staff, will make certain that you are heavily sedated so that you do not feel any pain, and do not remember the procedure. Once you are asleep, you will be monitored throughout the procedure and given oxygen. The interventional radiologist will keep everything sterile, and will wear a theatre gown and operating gloves. The skin of your neck will be cleaned with antiseptic and the rest of your body will be covered with a theatre towel. When you wake up, if you have had a general anaesthetic you will be in the theatre recovery area. You will have a small needle in your arm, or hand, probably with a bag of fluid attached to it. You may feel some stiffness in your neck where the needle has been inserted.

Will it hurt?

If you have a general anaesthetic, apart from having a small needle put into the back of your hand, you should not feel any pain and you should not remember the procedure. In the same way, you should not feel any pain if you are sedated. There will be a nurse, or another member of staff, standing next to you and looking after you. If you are aware of any pain, then you can let them know, and they will arrange for you to have more painkillers or sedatives through the needle in your arm.

How long will it take?

Every patient’s situation is different and it is not always easy to predict how complex or how straightforward the procedure will be. It may be all over in 45 minutes but it can take up to four hours.

What happens afterwards?

As stated, you will wake up in a theatre recovery ward if you have had a general anaesthetic. You will then be taken back to your ward on a trolley. Nurses on the ward will carry out routine observations, such as taking your pulse and blood pressure, to make sure that there are no untoward effects. You will generally stay in bed for a few hours until you have recovered. Once you have recovered from the procedure, you will probably feel no different than you did before, except that hopefully, the bleeding which was part of your problem should no longer happen, or the fluid in your abdomen should begin to drain away. It is possible that you will be asked to stick to a new diet. This may have a very low protein and salt content. You must talk to the dietician if such a diet is recommended. You will also be asked not to drink any alcohol.

Is TIPSS permanent and what happens next?

The stent that the radiologist has put in between your liver vein and your portal vein will stay in for the rest of your life. It can, however, become blocked and in order to prevent this the radiologist will ask you to attend the X-ray department regularly for ultrasound examinations to check your liver. With ultrasound, the radiologist will be able to see the TIPSS and see if it is becoming blocked. If at any time he or she thinks it is, they will ask you to come to the X-ray department for a day and will perform a very simple procedure to unblock the TIPSS. This procedure will not require a general anaesthetic. If you are having a liver transplant, then the radiologist will check the TIPSS until you have your transplant. If you are not having a liver transplant, you may have to come for regular checks for at least five years.

Are there any risks or complications?

TIPSS is a very complicated procedure. Generally it is very safe and you are carefully monitored by an experienced anaesthetist or by the radiologist and other trained staff. However, there are some risks and complications that can arise, as with any medical treatment. Perhaps the biggest problem is being unable to place the stent between the two veins. This can happen sometimes because the liver disease has made the liver very hard, and the needle will not pass through it. If this happens, you may need the open operation. Sometimes, even though the TIPSS has been performed satisfactorily, bleeding can continue. This is because the high pressure in the portal vein has made the veins very delicate. If this happens, you may need to go back to the X-ray department and have these veins blocked off with little metal coils. This is a fairly simple procedure and does not require a general anaesthetic.
Because patients with jaundice are likely to have difficulties with blood clotting, there may be some bleeding from the liver, where the needle was pushed between the two veins. On very rare occasions this may require a blood transfusion. If the bleeding continues, the bleeding blood vessel may need to be blocked off. Again, this is a very simple procedure and will not require a general anaesthetic.
You may also develop a bruise in your neck, which can be a bit sore for a day or two.
Because the liver takes waste products out of the blood stream, if too much blood bypasses the liver, the waste products can remain in the blood and can cause you to become confused. If this happens you may require the diet mentioned previously, and if it is severe it may be necessary to block off the TIPSS on purpose.
Some of your questions should have been answered, but remember that this is only a starting point for discussion about your treatment with the doctors looking after you. Do satisfy yourself that you have received enough information about the procedure, before you sign the consent form.
TIPSS is considered a safe procedure, designed to save you having a larger and more dangerous operation. There are some risks and complications involved, and although it is difficult to say exactly how often these occur, they are generally felt to be less severe than the risks of untreated portal hypertension.

© The Royal College of Radiologists, July 2000.

Alcohol and its Effects on the Liver

Alcohol and its Effects on the Liver


Ethanol Metabolism


Ethyl alcohol, also known as ethanol, is a product of yeast fermentation. Unlike carbohydrates and fats, ethanol is not stored in the tissues of the body. A minimal amount can be eliminated through the lungs and kidneys, but the body essentially rids itself of ethanol through metabolic processes. Because the liver contains the necessary enzymes to break down ethanol, this organ is heavily relied upon for the metabolism of ethanol. More than 90% of ethanol intake will be oxidized to acetic acid via two major metabolic pathways within the liver. The remaining ethanol that is not metabolized is excreted in urine, sweat, and breathing.

Within the cytoplasm of liver cells, 2 hydrogen atoms are removed from an ethanol molecule by the enzyme alcohol dehydrogenase, forming acetaldehyde. This is oxidized in mitochondria by aldehyde dehydrogenase to form acetic acid, which is further broken down into CO2 and H2O. The reaction pathway is as follows:
CH3CH2OH + NAD+ -> CH3CHO + NADH + H+






Another route of ethanol metabolism within the liver is known as the microsomal ethanol-oxidizing (MEOS) system, which involves ethanol oxidation by cytochrome P450. The MEOS system does not have as large a role in ethanol metabolism as the alcohol dehydrogenase pathway, but it begins to become more important when concentrations of ethanol become very high. This pathway results in the same byproducts of acetaldehyde and acetic acid, but uses NADPH instead of NAD+ as a reducing factor. The process also uses O2, which generates free radicals that can damage tissues. The reaction pathway due to MEOS catalysis is:
CH3CH2OH + NADPH + O2 -> CH3CHO + NADP+ + H2O



The single most common cause of liver disease is the chronic consumption of ethanol. The damage results from the alcohol itself and also from the byproducts produced from its breakdown. These damaging byproducts include acetaldehyde and free radicals. A buildup of the reactive acetaldehyde leads to covalent bonding with protein functional groups, impeding protein function. High levels of this compound lead to cell death and liver damage.



Because the liver has an enormous regenerative capacity, liver damage usually occurs only in alcoholics who have been drinking excessive amounts of alcohol for many years. Three main categories of liver disease include: fatty liver, alcohol hepatitis, and alcoholic cirrhosis. Fatty liver is the result of fat deposits in the liver and is reversible. This can result from just one incidence of heavy drinking, but usually does not lead to any further problems. Alcoholic hepatitis is the inflammation and destruction of liver cells due to chronic alcohol consumption. While it may be fatal it can be reversed simply by cessation of alcohol intake. Alcoholic cirrhosis is the extensive scarring of the liver, often following alcoholic hepatitis when the affected individual continues drinking. The replacement of normal functioning liver tissue with fibrotic scar tissue results in the loss of liver function and also the stiffening of blood vessels, leading to portal hypertension as the internal structure of the liver is destroyed.



Alcoholic Hepatitis


Alcoholic Hepatitis is an inflammation of the liver resulting from the continual consumption of alcohol. As with inflammation of other organ systems, alcoholic hepatitis results in an increased blood flow to the liver, swelling of the liver, an influx of white blood cells, and pain. In addition to the damage caused by alcohol, those alcoholics who develop hepatitis or cirrhosis may also suffer from malnutrition due to the consumption of alchol which contains many calories without any of the essention nutrients, proteins or vitamins. This malnutrition can contribute to liver disease. While Alcoholic Hepatitis does not directly lead to cirrhosis, cirrhosis is most commonly found in those who are alcoholics, which is also the main group affected by alcoholic hepatitis.

The following figure is a normal Liver tissue. Liver is divided histologically into lobules. The center of the lobule is the central vein. At the periphery of the lobule are portal triads. Functionally, the liver can be divided into three zones, based upon oxygen supply. Zone 1 encircles the portal tracts where the oxygenated blood from hepatic arteries enters. Zone 3 is located around central veins, where oxygenation is poor. Zone 2 is located in between.


Below is the normal image of the liver with normal hepatocytes.

The following are the images of liver with alcoholic hepatitis and the presence of swollen, degenerative hepatocytes. The tiny black dots are white blood cells indicating inflammation of hepatocytes. Furthermore, the lipid accumulates in the hepatocytes as vacuoles. These vacuoles have a clear appearance with H&E staining.



And here is the image of a cut surface of liver with alcoholic hepatitis. The green color results from bile pigment.




Alcoholic Cirrhosis


Cirrhosis is characterized by the replacement of functional liver tissue with fibrotic scar tissue. This leads to a decrease in functional liver mass. While cirrhosis is usually seen after fatty liver or alcholoic hepatitis occur, this is not a cause and effect relationship. The liver tissue is replaced by nodules (either microscopic, macroscopic, or mixed) separated by fibrous septa. Micronodular cirrhosis is usually the result of chronic alcohol consumption while macronodular cirrhosis is normally due to infectious agents such as viral hepatitis. These nodules are a result of the regeneration process gone slightly off course. The new hepatocytes are displaced and the normal lobular structure of the liver, so critical to its function, is interrupted. After chronic injury and replacement the cells continue to regenerate but they are not replaced within their normal structure. The normal structure of a portal triad is show below. We can see the portal vein, the hepatic artery and the bile duct.
In this next picture we can see that the lobulated structure of the liver has been destroyed. New hepatocytes seem to be strewn about in a disorderly manner. These regenerated nodules are separated by fibrous septa as denoted in the picture.

Below is a schematic picture taken from the Mayo Clinic's web site. We can see on the left is a normal healthy looking liver. On the right is what the liver of a patient with cirrhosis would look like. Note the lobules separated by fibrous septa. The entire internal structure of the liver is also destroyed.

Here we can see two schematics; on the right, a healthy liver showing the portal triad structure while on the left is a schematic of the early stages of cirrhosis. Hepatocytes die and are replaced by scar tissue, damaging the liver structure.
 

Hepatitis C


Hepatitis C is a liver disease that is caused by hepatitis C virus and is found in the blood of the infected person. It is spread by contact with the blood of the infected person. This virus is an RNA virus and there is no relationship between hepatitis C virus and the other hepatitis causing viruses. There are several ways to share this virus including transmission of infected blood, sexual intercourse and needle sharing.


Hepatitis C is the most prevalent viral liver disease in the United States. It is often called the “silent epidemic”, because the symptoms might not become visible for some years. Hepatitis C virus emerged in the United States first in the 1960s as a result of a blood transfusion. It was only in the 1990s when the researchers first discovered a blood test for this virus. According to a study, 20% of people who suffer from chronic hepatitis will end up with liver cirrhosis and liver cancer.

There are 270-300 million people suffering from Hepatitis C worldwide; 4 million of which live in the United States. Hepatitis C virus accounts for 20% of the acute hepatitis cases, 70% of chronic hepatitis cases and 40% of end-stage cirrhosis cases. For every person infected with AID, there are 4 people who are infected with HCV. There are 26000 cases every year. HCV accounts for 10000 to 12000 deaths per year.

It has been estimated that the chronic HCV will become one of major diseases affecting many people. It has been estimated that in the United States, there will be a 60% increase in the incidence of cirrhosis, 68% increase in hepatoma incidence, and a 223% increase in liver death rate.


Most acutely and chronically infected people with the virus are free of symptoms for years. Unfortunately by the time the liver damage is diagnosed, it is usually irreversible and results in liver cancer. In the first few years, the only way to detect hepatitis C is through liver biopsy.


There are two forms of hepatitis C: acute and chronic. Acute hepatitis C is a newly acquired infection and can be cleared within 6 months. Some of the symptoms of acute hepatitis are headache, nausea, vomiting, jaundice, weakness and fatigue. Acute form of hepatitis might last from several weeks to several months. Some may recover from the infection and have no long lasting problems.


However, chronic hepatitis C is a long term infection that can last for years. In the beginning, some of the symptoms of the chronic form may include anxiety, blurred vision, vomiting, weakness and weight loss. The symptoms usually progress very slowly but usually end up in severe liver disease such as liver cirrhosis and liver cancer.