Portal Hypertension

As blood travels around the body it goes through the digestive system to pick up the nutrients from food which has been eaten. This blood then takes these nutrients to the liver through a blood vessel called the portal vein. This is called the portal circulation. The liver processes the blood before it goes back to the heart.
Hypertension means high blood pressure. When the pressure of the blood in the portal circulation is unusually high this is known as portal hypertension.

Portal hypertension is most often caused by difficulty in blood flow into the liver which then causes a build-up of pressure.

The main causes of this happening are:

• A blockage in the portal vein. This can happen if a blood clot (thrombus) stops blood from passing through the portal vein freely. This is called portal vein thrombosis. In this situation the liver may be completely normal and healthy.
• Scarring in the liver due to cirrhosis or fibrosis. Cirrhosis occurs as liver cells are damaged and die. They are then replaced with scar tissue (fibrosis).

Occasionally, a blockage of the hepatic vein draining blood from the liver can cause increased pressure in the portal vein, but this is not common in children.

Often portal hypertension will not cause any symptoms, but the onset of any symptoms relating to portal hypertension will be monitored. If portal hypertension causes troublesome symptoms, it may be referred to as severe or complicated portal hypertension.

The increased pressure in the affected blood vessels can affect other areas of the body. Potential problems include:

An enlarged spleen (splenomegaly)
The spleen is connected to the liver by a vein which joins the portal vein. This means that if there is high pressure in the portal vein, this may affect the spleen, causing it to enlarge.

The spleen’s job is to break down old blood cells. When it gets larger it removes more blood cells than it should. This includes a type of blood cell called platelets which help to stop bleeding. Not having enough platelets can lead to bruising and nosebleeds.

Abdominal swelling
Ascites can be the reason for a child’s tummy suddenly getting bigger. Ascites is a collection of fluid in the tummy (abdomen). Portal hypertension can cause this because the high pressure in the blood vessels pushes fluid out of these blood vessels into the space between the organs.

Abdominal swelling can also be caused by the spleen and liver getting larger. If this is the cause the tummy is not normally as swollen as it is with ascites.

Noticeable veins under the skin of the tummy
Veins can appear under the skin of the tummy because it is swollen. They can also appear because blood returning to the heart through the portal vein is blocked. The blood is then forced out of its usual route and new veins form to get around the blockage. When this happens near the surface of the skin the veins may be seen.

Varices
As well as veins becoming visible over the surface of the tummy, other veins can become enlarged, especially in the digestive tract (the oesophagus, stomach and intestine). These are called varices. They look similar to varicose veins which people can have in their legs. When these form in the food pipe (oesophagus), stomach or rectum they can bleed as they have thin walls.

Signs of Bleeding
Varices have thin walls and may bleed. Bleeding can cause tiredness and can cause a child to feel short of breath. It can also cause a pale appearance.

Blood might appear when a child is sick and may appear in their stool (poo) which can be blood stained or black.

If there is a large bleed a child may have tummy pain, be dizzy and may collapse. Whatever the sign of bleeding, seek emergency medical advice by calling 999.

Diarrhoea and poor weight gain
The blood vessels which line the intestine can become swollen as blood flows through them under a high pressure. This can lead to fewer nutrients and less fluid being absorbed from food travelling through the intestine leading to diarrhoea and poor weight gain.

There are tests which can be done to find out whether a child has portal hypertension. These include:

A general physical examination

An ultrasound scan
This is the same scan pregnant women have. It is used to measure the size of the liver and the spleen. If the spleen is larger than expected this may suggest the child has portal hypertension. The scan can also be used to check the direction of the blood flow in the veins around the liver.

Endoscopy
A flexible tube, called an endoscope, is passed into the mouth, down the oesophagus, through the stomach and the intestine. This allows the doctor to look directly at the lining of the digestive tract to see if there are varices. This is usually done under general anaesthetic (where the child is completely asleep) or under sedation (where the child has drugs to make them sleepy and relaxed).

Colonoscopy
This is similar to the endoscopy but the tube is passed up the anus to examine the lower intestine. It is often not needed to make a diagnosis.

Blood test
Your child will have blood taken and the levels of platelets will be reviewed.

There are some cases where a child has portal hypertension without having a known liver disease. These children may need more tests including:

Angiography
Under anaesthetic, a thin tube is passed into a blood vessel in the groin or neck and a special dye is injected. X-rays are then taken to give a ‘map’ of the portal vein and its branches and also measure the blood pressure in the liver vessels.

Magnetic resonance imaging (MRI)
A cannula or drip is inserted, which is used to pass dye into the vein. It then involves lying on a bed in a long circular tube whilst computerised pictures are taken.

Sedation or anaesthetic is not normally required provided the child is able to stay still, but in young children an anaesthetic may be needed.

If there are no symptoms or complications, then treatment may not be required, although the child’s condition will be monitored. Treatment may be needed if the varices are significant in size according to international grading criteria and if there is an underlying liver condition which has caused the portal hypertension. If portal hypertension leads to varices which bleed, treatment of the varices will definitely be required.

The main treatment options for varices are called banding and sclerotherapy. These are explained further on.

Children with portal hypertension may also have varices in gut areas that are not accessible by endoscopy and endoscopic treatment may not be possible. However, other non-endoscopic treatment options are available.

In contrast to adults, there isn’t currently strong evidence on medicines that can help in the management of portal hypertension in children.

Banding
When portal hypertension is confirmed, an endoscopy will be planned to assess whether varices are present. The timing of this will depend on the age and size of the child, as well as any complications that are known to be present, such as an enlarged spleen and low platelet count. During the endoscopy, if varices are present, the doctors will grade them according to their size. If necessary, the varices will be treated at the time of the endoscopy. Banding involves placing a medical rubber band over the affected blood vessels (the varices).

This causes the blood in the varices to clot or thrombose. This means that blood cannot flow through the varices which reduces the risk of bleeding. The elastic band will fall off and may be seen in a child’s stool (poo) after a few days, although it is tiny and may not be noticed.

Banding can be done urgently when your child is an inpatient, or it can be a planned procedure. Repeated endoscopies are usually needed to improve the varices, usually with intervals of weeks or months between each session.

Sclerotherapy
Another treatment for varices is called sclerotherapy. This is performed when banding may not be possible, for example, in a very small child.

An endoscope is passed down the oesophagus, a needle is passed through the endoscope into or next to the varices and a chemical is injected. The chemical causes the varices to clot and close off.

No. A child can have portal hypertension for years without having any related problems.
The varices which form may develop in areas of the body where they will not bleed. These veins help the blood flow back into the main circulation via a new route so the blood pressure in the portal circulation is lowered.

Bleeding is more likely if varices form in places where the walls of veins are thin, including the oesophagus and the stomach.

If the varices have inflamed the lining of either the oesophagus or the stomach then a medicine will be given to protect the lining and help it to heal.

If a child is vomiting blood or passing blood in their stools then ring 999 straight away.

The team at the hospital should be told that the child has a diagnosis of portal hypertension and be given a description of the symptoms. The medical team will give families a letter to carry with them to show the emergency doctor.

In hospital the child will be assessed and treated if needed. Some bleeds may be very small but in general it will be recommended that your child remains in hospital for observations and an endoscopy will be organised in the liver centre.

The hospital team caring for your child may:

• monitor the child’s blood pressure and pulse
• observe the vomiting/colour of stools
• find out how much blood has been lost
• give the child fluid/blood through a drip
• give medicines to stop the bleeding
• contact you liver team and discuss management plan
• perform an endoscopy to look at the varices which are bleeding
• treat the varices by putting rubber bands around them (banding) or by injecting the varices with a chemical to stop the bleeding (sclerotherapy)

Children can be managed for years on banding programmes. If the programme no longer manages the varices effectively then further treatment options are available. These options can be surgical in the form of creating a bypass in the portal system (if there is a blockage), a shunt (if there is high pressure in the system) or replacing the liver and its vessels (liver transplantation).

Medicines such as aspirin and ibuprofen should be avoided as they can make bleeding in the gut more likely. Paracetamol (Calpol) is a safer alternative.

It is important to be aware of the potential issues which could occur e.g. bleeding. It is vital that all carers and teachers are aware of what to look for and what to do if they notice any signs that there may be a problem.

If the spleen is enlarged there is a higher chance of it being damaged if it receives a hard blow so children may be advised to avoid activities where they may receive a blow to the abdomen e.g. contact sports such as kick boxing and rugby. Most physical activity however is to be actively encouraged and children should participate in PE at school.

It’s important not to limit activities unnecessarily and the child’s medical team will be able to provide specific advice on a case by case basis.

If a child with portal hypertension is travelling/flying it’s important that their medical team are informed well in advance as the child may need treatment before going away.

In rare cases of portal hypertension the veins in the lungs can also be affected. Children may develop hepatopulmonary syndrome characterised by:

• low oxygen levels in the blood due blood vessels in the lungs dilating and mixing of oxygenated with nonoxygenated blood.
• portopulmonary syndrome. This is where there is high blood pressure in the pulmonary veins due to resistance to blood flow through the circulatory system.

Heart and lung investigations will be required to establish the diagnosis and liver transplantation is usually the treatment of choice.