Aortic valve replacement
Aortic valve replacement
Aortic valve replacement is a type of open-heart surgery and is used to treat problems with the heart's aortic valve.
The aortic valve
The heart has four chambers. There are two small chambers at the top of the heart (atria) and two larger chambers at the bottom (ventricles).
Each ventricle has two valves:
one valve controls the blood flowing into the ventricle
the other valve controls the blood flowing out of the ventricle
Each valve is made up of flaps, which are also known as leaflets or cusps. These flaps open and close, acting as one-way gates for the blood to flow through.
The aortic valve controls the flow of blood out of the heart's left ventricle to the body’s main artery (the aorta). From here, the blood travels to the rest of the body.
First, the aortic valve opens to allow blood to flow from the heart to the rest of the body. It then closes, to stop any blood leaking back into the heart.
Why is it necessary to replace the aortic valve?
The aortic valve may need to be replaced for two reasons:
narrowing of the valve (aortic stenosis) – the aortic valve becomes narrowed and obstructs the blood flowing through it
leaking of the valve (aortic regurgitation) – the aortic valve leaks and blood flows back through into the left ventricle
If the aortic valve is no longer working properly, surgery is usually needed to replace it.
How is aortic valve replacement carried out?
During surgery, a cut is made in the chest to access the heart. The heart is then stopped and a heart-lung bypass machine is used to take over the circulation during the operation.
The aortic valve is removed and replaced with an artificial valve (prosthesis). The heart is then started again and the chest incision is closed.
An aortic valve replacement carries a risk of complications, some of which can be life-threatening. Around 1 in 50 people who undergo this type of surgery die from complications either during or shortly after surgery.
However, if aortic stenosis and aortic regurgitation are not treated, there is a much higher risk of dying from these conditions. However, the benefits of aortic valve replacement will usually far outweigh any associated risk of surgery.
Alternatives to aortic valve replacement
An aortic valve replacement is the most effective treatment for aortic stenosis and aortic regurgitation. Alternative treatment options are usually only used if a person is too frail for open-heart surgery, or using the standard method carries a high risk of complications.
Alternatives to aortic valve replacement include:
transcatheter aortic valve implantation – the replacement valve is guided into place through the blood vessels rather than through a large incision in the chest
aortic valve balloon valvuloplasty – the valve is widened using a balloon
sutureless aortic valve replacement – the valve is not secured using stitches (sutures), to minimise the time spent on a heart-lung machine
How common is aortic valve replacement surgery?
Almost 5,000 aortic valve replacements were carried out on the in England between April 2011 and April 2012.
An aortic valve replacement requires both specialised training and equipment. However, your local hospital may not be able to provide this treatment.
If this is the case, you will be transferred to a hospital that does.
Illustration of aortic valve replacement
Plastic repair of valve
Having an operation
If your GP has suggested you may need surgery, this guide is for you
Why you might need an aortic valve replacemen
Aortic valve replacement is used to treat conditions affecting the aortic valve. These are known as aortic valve diseases.
The two main aortic valve diseases are:
aortic stenosis – when the valve is narrowed, restricting blood flow
aortic regurgitation – when the valve is allowing blood to leak back into the heart
Aortic valve diseases can be classified as:
congenital – when you are born with it
acquired – when the disease develops in later life, usually over many years
The most common reasons why a person develops one of these diseases are described below.
Common causes of aortic valve disease
Senile aortic calcification
Senile aortic calcification is the most common cause of aortic valve disease. It is a degenerative disease, occurring as a result of ageing. Calcium deposits form on the valve, preventing it from opening and closing properly. People with this form of the condition are usually diagnosed in their 70s or 80s.
Bicuspid aortic valve
A bicuspid aortic valve is the most common type of congenital aortic valve disease, affecting around 1 in 50 people. It occurs when the aortic valve has only two flaps instead of the usual three. The valve may function normally for years without you being aware of the problem, often until you reach your 50s or 60s.
Underlying health conditions
Several health conditions can damage the aortic valve, causing aortic valve diseases. These include:
Marfan syndrome – a genetic condition that damages the connective tissue (which provides support and structure to other tissue and organs)
Ehlers-Danlos syndrome – a group of inherited conditions that affect collagen proteins in the body, leading to fragile body tissues and sometimes heart valve problems
rheumatic fever – this condition can be due to a complication from a throat infection and causes widespread inflammation throughout the body (this is uncommon in the UK, however)
lupus – when the immune system attacks healthy tissue
giant cell arteritis – a condition that causes inflammation of the lining of the body’s arteries
ankylosing spondylitis – a type of chronic (long-term) arthritis that can lead to inflammation of the aorta (aortitis)
endocarditis – a rare but serious condition where the inner lining of the heart becomes inflamed
Symptoms of aortic valve disease
If you have a problem with your aortic valve, you may not experience any symptoms until the later stages of the condition. Any symptoms you have are due to your heart being unable to pump blood around your body efficiently. Symptoms can include:
chest pain brought on by physical activity (angina) – caused by your heart having to work harder, due to the restricted blood flow through your aortic valve
shortness of breath – at first you may only notice this when you exercise, but later you may experience this even when resting
dizziness or light-headedness – caused by the obstruction of blood flow from your heart to the rest of your body
loss of consciousness (fainting) – also a result of reduced blood flow, caused by obstructed blood flow
If your GP suspects you have aortic valve problems, they will refer you to a heart specialist (cardiologist) to do some tests. These will be:
an echocardiogram – where an ultrasound scan is used to obtain a detailed image of your heart. An echocardiogram can often detect abnormalities with the shape and movement of the heart valves
a coronary angiography – a type of X-ray that uses a special dye to helps your heart's blood vessels show up clearly on an X-ray
These tests should be able to confirm a suspected diagnosis of aortic stenosis or regurgitation.
When surgery is required
If your symptoms are mild, you will be invited to come in for an echocardiogram every year or two, to check if the problem is worsening.
If your symptoms are severe, you will probably need surgery to replace the valve. Without treatment, stenosis or regurgitation of your aortic valve is likely to get worse and will eventually lead to heart failure, which can often be fatal.
There is also a small but significant risk that the heart will suddenly stop beating (sudden cardiac death), which can also be fatal.
Preparing for your aortic valve surgery
Before having an aortic valve replacement, you will attend a pre-admission clinic. Here, you'll be seen by a member of the team, who will look after you in hospital.
At the clinic, you will have a physical examination and will be asked about your medical history.
Any investigations and tests that you need will be arranged – these could include a blood test or an X-ray. This is a good time to ask questions about the procedure, although your doctor will be happy to discuss these with you at any time.
You will be asked if you are taking any tablets or other types of medication. These might be prescribed by your GP or bought over the counter in a pharmacy. It helps if you bring with you details of any medication you are taking (perhaps take the packaging along).
You will be asked about any previous anaesthetics you've had, and if you experienced any problems or side effects, such as nausea. You will also be asked about any known allergies, to avoid an allergic reaction to any medication.
You will be asked about your teeth, including whether you have dentures, caps or a plate. This is because during the operation you will need to have a breathing tube inserted into your throat to help you breathe, and having loose teeth could be dangerous.
If you smoke, you will be advised to stop. Quitting smoking will lower the risks of complications after surgery, such as a chest infection or anembolism.
It is likely you will be in hospital for at least seven days, so you will need to make some practical preparations. These include bringing clothes, toiletries and any equipment you use, such as a walking stick or hearing aid.
How surgery is performed
An aortic valve replacement is carried out under general anaesthetic. This means you will be asleep during the operation and not feel any pain.
The surgeon will begin the operation by making a large cut down the centre of your breastbone (sternum). This will be around 25cm (10 inches) long.
This is known as a sternotomy and it allows the surgeon to access your heart.
Tubes are inserted into your heart and major blood vessels, which are attached to a heart-lung (bypass) machine. When this is turned on, your blood is diverted into the machine instead of your heart. The machine pumps oxygen-rich blood around your body until the operation is complete, taking over the role of your heart and lungs.
Your heart is stopped by filling the coronary arteries (the blood vessels that supply your heart with blood) with a chemical solution. The body’s main artery (aorta) is clamped shut, so that your surgeon can open your heart and operate without blood pumping through it.
Replacing the aortic valve
Your surgeon will open up your aorta, so that they can see the aortic valve. The damaged valve is removed, and the new one put into place and attached with a fine thread (suture).
The surgeon will start your heart again, using controlled electric shocks, before taking you off the bypass machine. Your breastbone will be joined up with wires, and the wound on your chest closed using dissolvable stitches. Tubes are inserted into small holes in your chest (called chest drains) to drain away any blood and fluid that builds up.
The operation may be performed using smaller incisions and instruments, but you will still need to be connected to the bypass machine. In the future, it may be possible to perform this operation in a less invasive way, without the need for a bypass machine.
Choice of valve
There are two main types of replacement valve:
Mechanical valves, which are made of man-made materials such as pyrolytic carbon (similar to graphite)
Biological valves, which are made of animal tissue
Each type of valve has advantages and disadvantages, which your doctor can discuss with you.
Generally, if you are under 60 years of age, the surgeon will recommend a mechanical valve replacement. If you are over 65, a biological valve replacement is usually recommended.
Mechanical valves are very hard wearing and long lasting.
However, there is a tendency for blood to clot on the surface of the valve. You will have to take anticoagulant (blood-thinning) medicationto prevent clots forming.
There is a small risk of blood clots causing a stroke, when the blood supply to your brain is disturbed.
Mechanical valves can make a clicking noise, which can be disturbing at first, although is very easy to get used to.
With biological valves, there is less risk of blood clotting. Therefore, anticoagulant medication is not usually needed, unless you are taking it for other problems.
However, biological valves may not last as long in younger, more active people, so a replacement valve may be needed.
How long does the surgery last?
The operation usually takes 2 to 3 hours. The time from having the anaesthetic to waking up in the recovery room or intensive care unit (ICU) will be around 10 to 12 hours.
Recovering from surgery
After an aortic valve replacement, you will be taken to an intensive care unit (ICU). Here, the activity of your heart, lungs and other systems will be closely monitored for the first 24 to 48 hours.
You may be kept asleep for a few hours after your operation, or until the following morning, and you will remain on a ventilator during this time.
A ventilator is an artificial breathing machine that moves oxygen-rich air in and out of your lungs. This is done through a tube, called an endotracheal tube (ETT), which is placed in your mouth and sometimes also in your nose. The tube will usually be held in place behind your neck.
When you wake up, the tube will still be in place and may be uncomfortable. You will not be able to talk or drink anything. Once the intensive care team are satisfied that you can breathe on your own, you will be taken off the ventilator and the tube will be removed. A mask will be placed over your mouth and nose to supply oxygen for you to breathe.
As with any major operation, you can expect to have some discomfort after an aortic valve replacement.
While you are in hospital, you will be given painkillers for when your anaesthetic wears off.
If the painkillers are not effective, tell a nurse or the doctor in charge of your care. You may need a stronger painkiller.
You will also be given advice about painkillers to take at home. Discomfort is likely after your operation, but will get better as the wound heals.
Moving to a ward
You will be moved from the ICU to a surgical ward, once the doctors treating you think you're ready. This will probably be a high dependency unit (HDU) for people who need to be kept under observation after an operation.
You may have several tubes and monitors attached to you. These could include:
chest drains – small tubes from your chest to drain away any build-up of blood or fluid (these will usually be removed the day after your operation)
pacing wires – if necessary, these will be inserted near the chest drains to control your heart rate (they will usually be removed after four or five days)
wires on sensor pads – these can be used to measure your heart rate, blood pressure and blood flow, and the air flow to your lungs
a catheter – a tube that is inserted into your bladder so that you can pass urine
On the ward, your care team will focus on increasing your appetite and getting you back on your feet.
Depending on how well you progress, you should be able to leave the hospital 7 to 10 days after your operation.
Someone from the cardiac rehabilitation team or physiotherapydepartment will discuss your rehabilitation with you before you go home.
They can give you advice on how to get back to normal, and where there is a cardiac rehabilitation programme or support group in your area. The aim is to help you recover quickly and get back to living as full and active a life as you can, while preventing further heart problems.
The recovery time after aortic valve replacement surgery varies from person to person and will depend on:
your overall health and fitness
how well you were before the operation
Your breastbone usually takes about six to eight weeks to heal, but it may be two to three months before you feel completely normal.
You may feel anxious about your recovery and how you will manage without full-time nursing care. Take things slowly and at your own pace. Here are some mild and short-term symptoms you may experience after you leave hospital:
loss of appetite – it may take a while for this to return and you may temporarily lose your sense of taste
swelling and redness – your incision may be swollen and red, but this will gradually fade. Seek medical help if it becomes more painful
insomnia – some people have problems sleeping. This should improve with time, and taking a painkiller before bed may help
constipation – you may find it difficult to go to the toilet. Drinking plenty of fluid and eating fruit and vegetables will help. Your doctor may also suggest taking a laxative (a medication to help you pass stools more easily)
anxiety and depression – these are completely normal after heart surgery. Talking to your friends and family can help, and you cardiac or district nurse can also offer support. You will start to feel emotionally stronger as you regain your health and strength
Caring for your wound
You will have a scar where the surgeon cut down your breastbone. The scar will be red at first, but will gradually fade over time.
When having a bath or shower, wash your wound using mild soap and water. In hospital, you should be able to have a shower after your pacing wires have been removed (after four or five days). Avoid very hot water and soaking in a bath until your incision wound has healed.
Protect the wound from exposure to sunlight during the first year after surgery, as the scar will be darker if it is exposed to the sun.
Call your doctor if you notice:
increased tenderness around the incision site
increased redness or swelling
pus or oozing
a high temperature of 38C (100.4F) or above
If dissolvable stitches have been used to close the wound, they should disappear within around three weeks. Other types of stitches may need to be removed by a healthcare professional, and you will be given a follow-up appointment to have your stitches removed, if necessary.
Sex after heart surgery
Before your operation, symptoms of fatigue or shortness of breath may affect your sexual activity. After your operation, you may feel like having a more active sex life. You can do so as soon as you feel ready, although avoid strenuous positions and be careful not to put any pressure on your wound until it has fully healed.
Some people find that having a serious illness can make them lose interest in sex. In men, the emotional stress can also cause impotence. If you are worried about your sex life, talk to your partner, a support group or your GP.
Driving after surgery
After your operation, you can be a passenger in a car straight away. However, you may not be able to drive again until around six weeks after you're discharged from hospital. Wait until you can comfortably do an emergency stop. If you're unsure, ask your surgeon for advice. If you drive a lorry or a passenger-carrying vehicle, you will need to tell the DVLA about your surgery.
Returning to work
When you can return to work will depend on the type of work you do, so ask your surgeon for advice. This could be as soon as six to eight weeks after you've been discharged from hospital.
However, if you do heavy manual work, it may up to three months before you can return. You may want to change your role to involve lighter duties, or speak to your occupational health department if your workplace has one.
Risks of aortic valve replacement
After an aortic valve replacement, several complications could occur, although this is rare.
Possible complications include:
Infection – the new valve can become infected and inflamed (endocarditis), which can damage your heart. You will be given antibiotics to reduce the risk.
Embolism (clotting) – this is more likely if you have had mechanical valve replacement. You will be prescribed anticoagulant medication if this is a significant risk.
Stroke or transient ischaemic attack (TIA) – the supply of blood to the brain becomes blocked.
The valve may wear out or become damaged – this is more likely if you are under 60 years old and have had a biological valve replacement.
Irregular heart beat (arrhythmia) – this affects 25% of people temporarily, and 1 to 2% of people need to have a pacemaker fitted (a small battery-operated device that is inserted under the skin in your chest to help your heart beat regularly).
Kidney failure – the kidneys do not work as well as they should, which affects around 3 to 5% of people.
Complications can be fatal, although the chance of any of the above occurring is rare. Data suggests that around 2% of people treated with aortic valve replacement will die in the first 30 days after surgery.
However, the risk of death from surgery is far lower than that associated with not treating severe aortic disease.
Alternatives to aortic valve replacement
Aortic valve replacement is the most effective treatment for aortic valve diseases. However, having open heart surgery can place tremendous strain on the body.
Surgery may be too dangerous for people who are in very poor health.
If this is the case, less invasive alternative methods may be required, which are detailed below.
Aortic valve balloon valvuloplasty
Aortic valve balloon valvuloplasty involves passing a catheter (a thin plastic tube) through a large blood vessel, into the heart. A balloon is then inflated to open up the narrowed aortic valve.
If this is done, open heart surgery may not be needed, although this is still the first treatment choice for adults.
Guidance from the National Institute for Health and Care Excellence (NICE) has recommended that aortic valve balloon valvuloplasty should only be used in people who are not suitable for traditional open surgery. It can also be used as a short-term treatment for babies and children, until they are old enough for valve replacement.
The main drawback with this type of treatment is that the effects usually only last around two to three years. After this, further treatment is required.
Transcatheter aortic valve implantation
Transcatheter aortic valve implantation is a relatively new procedure. It involves accessing the aortic valve through the femoral artery or vein (one of your major blood vessels), or through a small surgical incision in your chest.
A balloon catheter (a thin plastic tube with an inflatable balloon on the tip) is guided into the left ventricle chamber in your heart, and is used to position the prosthetic valve over the old one.
Transcatheter aortic valve implantation may be used if someone is too frail to cope with the stress of standard valve replacement surgery. This could be due to age or another illness.
While it is not as effective as traditional open heart surgery, a transcatheter aortic valve implantation does offer a marked improvement in survival for people with severe aortic valve diseases. One study found that this type of treatment could halve a person’s risk of death.
However, there is around a 1 in 16 chance of having a stroke in the first year after a transcatheter aortic valve implantation.
Sutureless aortic valve replacement
Sutureless aortic valve replacement is the newest alternative to traditional open surgery. The main difference between the two procedures is that there are no stitches (sutures) used to secure the artificial valve in place.
The aim of this procedure is to minimise the amount of time the operation takes, so there is less time spent on a heart-lung (bypass) machine. It may be an option for people who have a high risk of complications during the standard procedure.
As the procedure is relatively new, the long-term effects are not yet fully known. However, it is thought that the main risks of this treatment are blood leaking around the side of the replacement valve or a blood clot forming.
A leak may mean the procedure has to be repeated to fix the problem, or an alternative treatment may be used. If a blood clot forms, this could cause a stroke.