Mitral valve balloon dilation at Leeds Hospital

What is a mitral valve balloon dilation?

Mitral valve balloon dilation is a procedure that widens a narrowed mitral valve, one of the four valves that control the flow of blood through your heart. A doctor guides a thin, flexible tube (a catheter) with a small deflated balloon on the end into the valve, then inflates the balloon to stretch it open.

What conditions does it treat?

This procedure treats mitral stenosis, a condition where the mitral valve becomes narrow, thickened and stiff, making it harder for blood to flow from your lungs into the main pumping chamber of your heart. Mitral stenosis usually develops many years after a bout of rheumatic fever (an illness that can follow an untreated throat infection) in childhood, though many people don't remember having had it.

It's generally used once symptoms such as breathlessness, tiredness or chest pain don't settle with medicine alone. Occasionally, doctors also recommend it to prevent problems that mitral stenosis could cause later, such as during pregnancy.

What are the benefits of having a mitral valve balloon dilation?

Mitral valve balloon dilation can ease breathlessness, fatigue and chest pain by improving how well blood flows through your heart. It's less invasive than open-heart surgery, so many people feel the benefit quickly and recover faster than they would from surgery.

A good result is achieved in more than 85% of procedures. Around 80% of people remain free of significant symptoms 5 years afterwards, falling to 60-75% at 10 years and 30-40% at 20 years, though this varies a great deal depending on your age and the condition of your valve.

The procedure doesn't cure mitral stenosis, so you'll still need regular check-ups, ongoing medicines and a healthy lifestyle afterwards. For some people it delays the need for valve replacement surgery by years; for others, no further treatment is ever needed.

Are there different types or surgical approaches?

Balloon dilation is a single, standardised technique carried out using a catheter rather than open surgery, so there isn't a choice of surgical approach in the way there might be for some other heart operations. If balloon dilation isn't suitable for your valve, or the narrowing returns afterwards, the alternatives are surgical mitral valve repair or valve replacement.

Your cardiologist will decide whether balloon dilation is right for you based on things like how severe your stenosis is, whether the valve is leaking as well as narrowed, the shape of your valve, and your general health.

What happens before the procedure?

Before your procedure, you'll attend a pre-assessment appointment where our team checks your health, explains what to expect and answers any questions.

At this appointment, you can expect:

• a check of your health and medical history
• an ECG (a tracing of your heart's electrical activity) and blood tests
• swabs from your nose, groin and any skin wounds, to check for MRSA (a type of bacterial infection)
• advice on any blood-thinning medicines or diabetes medication you take, since some need pausing beforehand.

Anticoagulants (blood-thinning medicines) such as warfarin, apixaban, rivaroxaban, edoxaban and dabigatran are usually stopped around 3 days before the procedure. If you have a mechanical heart valve, you may need to come in earlier instead, to switch to a different blood thinner.

On the day, you'll need to:

• avoid eating anything after midnight
• have clear fluids only, such as water, tea or coffee, up to 2 hours beforehand
• shower with an antibacterial wash
• have any groin hair shaved in hospital, if needed, rather than beforehand at home
• see an anaesthetist and your cardiologist, who'll review your health and explain your pain relief and recovery
• sign a consent form before changing into a hospital gown.

What happens during the procedure?

1. You lie on your back on the X-ray table in the catheterisation room ('cath lab'), and heart monitor wires are attached to track your heart rate and rhythm throughout.
2. The anaesthetist gives you medicine through a small needle in your hand to make you sleep. Descriptions of the anaesthetic vary: most UK patient information describes a general anaesthetic alongside local anaesthetic in the groin, though some general descriptions of the procedure mention local anaesthetic with sedation alone.
3. Once you're asleep, an ultrasound probe is passed down your gullet (oesophagus) so the team can see your mitral valve clearly throughout; this is called a transoesophageal echocardiogram, or TOE.
4. The cardiologist inserts thin catheters into blood vessels, usually in your groin, and guides them towards your heart using X-ray and ultrasound images together.
5. A tiny hole is made in the wall between the heart's two upper chambers, allowing the catheter to reach the narrowed mitral valve.
6. The balloon is positioned across the valve, then inflated and deflated, sometimes more than once, until the opening has widened enough.
7. The balloon and catheters are removed, and the insertion site is closed, often with stitches, before pressure is applied to stop any bleeding and a dressing is put in place.

The procedure usually takes 1 to 1.5 hours, and you'll be asleep for most of it.

What does recovery look like?

In hospital

After the procedure, you're looked after in a recovery area before returning to the ward, where nurses check your blood pressure, pulse and the pulses in your feet, and record a heart tracing (ECG). These are routine checks to pick up any early signs of complications.

You'll need to stay lying flat for a few hours, sometimes longer, to let the puncture site in your groin seal properly. If your leg feels numb or weak at first, staff will help you get up safely, and you may need a bedpan or urinal rather than walking to the bathroom until feeling returns.

Most people go home the same day or the day after, once your doctor is satisfied with your recovery, though you'll need someone to drive you. You'll usually be connected to a drip for around 4 to 6 hours, and your medicines will be reviewed before you leave; occasionally, a repeat echocardiogram (heart ultrasound scan) is done first.

At home

Once home, take things gently for the first few days. Avoid heavy lifting, heavy cleaning, heavy shopping or gardening, and steer clear of strenuous exercise or lifting anything over 20lb (about 9kg).

You may not be able to drive for 2 weeks after your procedure, so please check with your doctor. Build up short walks of 5 to 10 minutes, several times a day, and avoid baths, hot tubs or swimming for the first 5 days, though showering is fine after 24 hours if you keep the spray off the wound.

Some bruising and discolouration around your groin, sometimes as far down as your knee, is common and not serious; it may pass from blue-purple to yellow over the following week, and paracetamol can help with any discomfort. Contact your GP if the area becomes increasingly painful, especially when walking, or if you notice a lump forming.

Seek urgent help (call 999) if you develop heavy bleeding from the groin site: lie down, press firmly on the site and get someone to call for help. You should also get urgent medical advice for chest pain, dizziness, fainting or sudden shortness of breath once you're home.

What are the risks and complications?

Every procedure carries some risk, and your own risk depends on your individual health and valve. Your cardiologist will talk you through how these apply to you before you give consent. The risks include:

• bruising or minor bleeding where the catheter goes in: very common, and usually settles with pressure within a few hours
• bleeding serious enough to need further treatment or surgery: about 1 to 5 in 100
• a leak in the mitral valve (regurgitation) severe enough to need valve replacement surgery later: about 5 in 100
• stroke, heart attack or minor bleeding: about 1 to 2 in 100 (one hospital's information gives stroke alone as less than 1 in 100)
• fluid or blood collecting around the heart, sometimes needing drainage: about 1 in 100
• an abnormal heart rhythm such as atrial fibrillation: about 1 in 100 (you're already more likely to develop this because of mitral stenosis itself)
• needing a permanent pacemaker afterwards: about 1 in 100
• death: about 1 in 200, though some UK patient information gives a broader estimate of less than 1 in 100
• a small persisting hole between the heart's upper chambers (atrial septal defect): less than 1 in 100, usually needing no treatment
• damage to a blood vessel needing surgical repair: less than 1 in 100
• damage to the heart muscle or valve serious enough to need emergency open-heart surgery: rare, but possible
• damage to teeth, throat or gullet from the ultrasound probe passed down your throat: estimates vary between sources, from about 1 in 10,000 up to fewer than 1 in 1,000
• a small radiation-related cancer risk from the X-ray equipment used: less than 1 in 1,000 to 1 in 10,000.

There's also a small, unquantified chance of infection at the catheter site, an allergic reaction to the contrast dye used for X-ray imaging, or the need for a blood transfusion if bleeding is excessive.