Mitral Valve Surgery
The heart is a complex pump with 4 one-way valves. The mitral valve is located between the left atrium and the left ventricle. Valves cease to function appropriately when the valve fails to open properly limiting the blood flow (mitral stenosis) or when the valve fails to close causing a large backwards leak (mitral regurgitation). Mitral regurgitation (MR) or a leaking mitral valve is most commonly caused by mitral valve prolapse where a section of the valve does not close properly. This is the most common cause of mitral valve disease in Australia.

The faulty mitral valve is replaced with a new valve. This is an example of a bioprosthetic or tissue valve which is constructed from the lining of a cow heart (bovine pericardium).
The Mitral Valve
The mitral valve is made of two leaflets than usually open and close freely. They are similar to a double-door and are prevented from opening in the opposite direction by chords that are attached to the edges of the leaflets (the doors). The leaflets are hinged on the annulus which is akin to the doorframe.
There are a number of causes for a mitral valve to leak. The annulus can be dilated so that the ‘doorframe’ is too wide for the doors (leaflets) causing a leak at the centre of the valve. The chords can rupture so that the leaflet swings back too far, or leaflet can have a hole in it (usually from infection).
With significant mitral regurgitation some of the blood is being pushed back towards the lungs instead of flowing out of the heart into the body. This results in a number of deleterious effects including significant shortness of breath, enlargement of the heart, palpitations, and ultimately heart failure. Regardless of the cause, if a patient has severe mitral regurgitation and especially if they have symptoms, surgery should be considered.
Diagnosis
Mitral valve disease may be picked up incidentally with a routine check up when a doctor can hear a ‘murmur’ in the heart with their stethoscope. This can often be discovered during childhood checks and many patients are aware that they have had mitral valve disease many years before they require surgery.
In other situations patients may present to their general practitioner with shortness of breath on exertion and a new heart murmur is discovered. They will be referred to a cardiologist who will perform an ultrasound of the heart – an echocardiogram. This will provide a detailed look of the interior of the heart – its function and the degree of mitral regurgitation or stenosis.
If someone has severe mitral regurgitation or stenosis they may be referred to a cardiothoracic surgeon for consideration of valve repair or replacement.
Who needs this procedure?
If someone has severe mitral regurgitation or mitral stenosis they may require surgery to repair or replace the mitral valve. Symptoms that can be noticed with mitral valve disease include shortness of breath, particularly on exertion or when walking up a hill or stairs. Other common symptoms are heart palpitations when the heart feels like it is ‘racing’ or beating irregularly.
Mitral valve disease can ultimately result in heart failure and this can present shortness of breath at rest, the inability to lie flat, waking up in the middle of the night short of breath and leg swelling.
Patients who have severe mitral regurgitation and have symptoms should undergo assessment by a cardiothoracic surgeon for consideration of mitral valve repair or replacement. Patients who don’t have symptoms are monitored regularly by their cardiologist. If the heart starts to fail or enlarge even without symptoms, surgery should be considered.
What is involved?
Mitral regurgitation or mitral valve prolapse can be corrected with either a valve replacement or valve repair. An excellent mitral valve repair is a superior option to replacement with better survival and decreased chance of infection.
Open mitral valve surgery is performed under general anaesthetic through a vertical incision down the middle of the breastbone (sternum) to expose the heart. The patient is connected to a heart-lung machine, which pumps blood through the body whilst the heart is stopped to operate on it. The mitral valve is accessed and repaired or replaced according to its condition. The operation takes approximately 3-4 hours.
Certain patients may be able to have their valve repaired or replaced without fully opening the chest (mini mitral). Dr Bassin will perform the surgery using minimally invasive techniques which ensures less pain and trauma for the patient and a far quicker recovery.
Mitral Valve Repair
In most cases of mitral regurgitation, the valve can be repaired by using a number of complex techniques to reconstruct its function.
Mitral valve repair has been associated with improved long-term survival because the heart function is preserved with the more natural function of a repaired native valve. There is also a reduced chance of infection compared with replacement as there is far less foreign material for bacteria to grow on.
Another significant consideration is that for younger patients, valve repair means that they can live without the blood thinner warfarin which would have been required for a mechanical (metal) valve replacement.
A successful mitral valve repair provides better long-term survival.
Mitral Valve Replacement
Mitral valve replacement is indicated for patients with mitral stenosis and in some cases for mitral regurgitation. The faulty valve is replaced with an artificial valve from these two broad categories: tissue valves and mechanical valves.
Generally, patients under the age of 60 will choose a mechanical valve and patients older than 65 will choose a tissue valve due to the differences in longevity of the valves and the need to be on blood thinners. In younger patients, tissue valves are found to be less durable for reasons that aren’t completely clear but may relate to their stronger immune system. When the valve fails a repeat surgery is generally required to place a new valve.
A mechanical valve will essentially last forever mechanically but requires the blood thinner warfarin for life. This is because the natural blood clotting system ‘sees’ the mechanical valve as foreign and will form a clot. If there is clot formation on a valve it can cause a catastrophic failure. Warfarin is a strong blood thinner that requires regular blood testing to monitor its effect and increases the risk of bleeding with trauma and surgery.
Ultimately, the choice of valve is individual and Dr Bassin will discuss this with each patient in detail.
Tissue Valve
A tissue valve is made from cow or pig material. This type of valve is usually more suitable for patients over the age of 65 as it lasts for approximately 10 years before needing a replacement and redo valve surgery. There is also no long-term requirements for the patient to take blood thinners.
Mechanical Valve
A mechanical valve is sometimes referred to as a metal valve, but is actually constructed from pyrolytic carbon. This valve more suitable for patients under the ago of 60, as they can last forever and don’t need a redo operation. The patient will need to take the blood thinner ‘warfarin’ to ensure the valve functions properly.
What is the recovery like?
What are the benefits and risks of this procedure?
When can I drive?
You may drive 4 weeks following surgery, according to the national guidelines.