Mitral Valve Surgery

Mitral valve prolapse

Mitral valve prolapse is where the mitral valve is too floppy and does not close tightly. Many people with a mitral valve prolapse do not have symptoms and it may only be spotted during a heart scan (echocardiogram) carried out for another reason.

Mitral valve prolapse can sometimes cause:

• dizziness
• breathlessness
• tiredness and lethargy
• an irregular heartbeat (arrhythmia) or noticeable heartbeats (palpitations)

Mitral regurgitation happens if the mitral valve can't close properly. This is usually due to either:

• the mitral valve becoming too floppy (mitral valve prolapse)
• the ring of muscle around the valve becoming too wide

These problems often develop with age - for example, because of "wear and tear" over time or damage caused by untreated high blood pressure.

Mitral regurgitation can sometimes be caused by a problem such as:

• cardiomyopathy - where the walls of the heart become stretched, thickened or stiff
• endocarditis - infection of the inner lining of the heart
• congenital heart disease - birth defects affecting the heart

If not treated, it can lead to atrial fibrillation - an irregular and fast heartbeat or pulmonary hypertension - high blood pressure in the blood vessels that supply the lungs or eventually heart failure - where the heart can't pump blood around the body properly.

Mitral stenosis

Mitral valve stenosis is where the mitral valve doesn't open as wide as it should, restricting the flow of blood through the heart.

Mitral valve stenosis may not have any symptoms. Sometimes it can cause:

• dizziness
• breathlessness
• tiredness
• noticeable heartbeats (palpitations)
• chest pain

If not treated, it can lead to atrial fibrillation - an irregular and fast heartbeat or pulmonary hypertension - high blood pressure in the blood vessels that supply the lungs or eventually heart failure - where the heart can't pump blood around the body properly

One of the main causes of mitral valve stenosis is rheumatic heart disease.

This is where an infection causes the heart to become inflamed. Over time, it can cause the flaps of the mitral valve to become hard and thick.

Other causes include hard deposits that form around the valve with age or a problem with the heart from birth (congenital heart disease).

Almost all operations on the heart will be performed under general anaesthetic. Your anaesthetist will review you before the operation and discuss the anaesthesia and the risks involved. The anaesthetist will outline what lines will be used for the procedure but usually these involve:

• A drip in your arm to put you to sleep
• A radial artery pressure monitoring line in your wrist
• An endotracheal tube (breathing tube) to help your breathing under anaesthesia
• A line in your neck to administer drugs
• A Transoesophageal (TOE) probe to assess your heart during surgery
• A catheter in your bladder
• Pad protection for your eyes

During the procedure a cut (incision) about 25cm long is made in your chest to access your heart – although sometimes a smaller cut (Keyhole incision- see below) may be made. The surgeon uses a heart-lung machine (cardiopulmonary bypass machine) to take over the work of the heart and lungs whilst the mitral valve surgery is being performed.

Mitral valve repair

One of the most common disease pathologies (degenerative disease) causing the mitral valve to leak, is usually best repaired. This helps to maintain the overall structure of the mitral valve and preserve the heart function. If the valve cannot be repaired, then a replacement is the only alternative.

The operation is carried out under general anaesthetic (where you're asleep). Your surgeon will usually get to your heart through a single cut along the middle of your chest, but smaller cuts between your ribs are sometimes used - minimally invasive or 'Keyhole surgery'.

The flaps of the mitral valve are then repaired, and a supporting ring (equivalent to a doorframe) inserted. The valve is tested during the operation to ensure that it is working properly, and a TOE performed at the end of the operation, again, to ensure that the repair is working well.

Mitral valve replacement

The operation is carried out under general anaesthetic. Your surgeon will usually get to your heart through a single cut along the middle of your chest, but smaller cuts between your ribs are sometimes used - minimally invasive or 'Keyhole surgery'.

The Mitral valve is replaced with either synthetic materials (mechanical) or animal tissue (tissue). Your surgeon should discuss with you the advantages and disadvantage of each type of valve taking into account your preference.

This is usually only done if you have mitral stenosis, or you have mitral prolapse or regurgitation and are unable to have a valve repair. You will also need to take medication (Warfarin) to prevent blood clots for at least 3 months after this operation if you have had a bioprosthetic valve replacement. If you have a man-made valve, you'll need to take this medication for life.

The breastbone is put back together with steel wire until the bone heals itself in 4-6 weeks.

In some operations, not all of the breastbone needs to be cut. This is called keyhole surgery or minimally invasive surgery. This can be performed in some centres where the procedure is performed regularly. This is called a Mini-MVR and can be performed with a cut to the side of your breastbone between the ribs. The heart-lung machine (cardiopulmonary bypass machine) is still used to perform the procedure, but you may need a separate cut in your groin to help with this.

After your operation you will be moved to intensive care for close monitoring until you wake up. The intensive care staff will only wake you once they are satisfied that you are stable. When you wake up you will notice that you still have the various lines inserted by the anaesthetist at the start of the operation but not the TOE probe.

Pain is usually controlled with strong painkillers in the first 24-48 hours after the operation, but most patients find that the chest wound is comfortable after that with only paracetamol required to ease the discomfort.

You will also notice some drains at the bottom of your wound that help monitor any bleeding that invariably happens to a degree after heart surgery as the blood can be very thin and may not clot (stop bleeding) properly after surgery. Occasionally if there is excessive drainage from the tubes before you wake up, then the surgeon may decide to take you back to theatre to reopen the wound and wash out the area around your heart. Whilst the surgeon hopes not to have to do this, it is always safer to do this if needed. The drains are usually removed on the first or second day after the operation.

You may also notice thin wires near the drains called pacing wires. These are often placed onto the surface of your heart at the end of the operation to help regulate the heart rate. They are attached to a device called a pacing box which provides the electrical stimulus to regulate the heart rate during recovery. If they are no longer needed, then they are removed on the third or fourth day after surgery. Occasionally, if they are still needed after four or five days, a permanent pacemaker will be fitted before you leave for home. Your heart surgeon and cardiologist will discuss this with you if needed.

Once your condition is stable, you will be moved to the high dependency unit or the cardiac ward. You should be out of bed in a day or two and return home after a week, with full recovery after two or three months depending on your fitness, age and how complex the operation was.

Most people get excellent relief from breathlessness and other symptoms caused by your faulty valve, and improved quality of life. The operation will hopefully prevent your heart function from deteriorating in the near future and can often improve function if there has been a reduction in your heart pump function.

The risks of heart bypass surgery are different from person to person, depending on the severity of heart disease, type of operation, age, and current state of health. You can visit our risk page on this website to help you understand these risks [link].

In many hospitals, after a heart operation, a member of the cardiac rehabilitation team will see you on the ward to give you information about your condition and the treatment you have had.

They will talk to you about making lifestyle changes and how to reduce your risk factors (the things that increase your risk of heart disease) to help protect your heart in the future. You can also ask the rehabilitation staff any questions about your recovery.

There are a number of options for treating leakage (regurgitation) or narrowing (stenosis) of your mitral valve

1. Follow up – If your mitral valve is only mildly or moderately diseased, your team may wish to follow you up with further tests (heart scans) over a period of time. Although leakage of the valve tends to progress and not improve spontaneously over time, the rate at which the valve function deteriorates can vary widely between individuals and therefore follow-up and timing of surgery will be tailored to you.
2. Medication – If you are too frail or choose not to want any intervention on your heart then medication can help control a number of the symptoms. It is important to realise that medication will only treat the symptoms for a period of time and does not treat the actual valve. Many patients will however benefit from continuing with medication alone.
3. TMVR – (Transcatheter Mitral Valve Repair or Replacement) – There are a number of rapidly evolving technologies and procedures being developed to improve valve function (repair) or to insert a stent and valve within your diseased mitral valve (replacement) without opening the chest or using the heart-lung machine. Because of the complexity of the mitral valve, these technologies are still being assessed and are not widely available.