Percutaneous (Minimally Invasive) Mitral Valve Repair
By Dr Paul Chaim
Published on Medical Grapevine on June 2015
The MitraClip device: A minimally invasive treatment option for mitral valve regurgitation
Mitral valve regurgitation (MR) (leaky mitral valve) is a common valvular abnormality. The mitral valve allows blood to enter the left ventricle where the blood is then pumped out of the heart to the rest of the body. When the mitral valve leaflets cannot close properly, leakage of the blood occurs from the left ventricle into the left atrium (mitral regurgitation) instead of being pumped out to the rest of the body.
Severe MR (leakage) leads to increasing breathlessness and heart failure. Open heart surgery to repair or replace the valve is recommended when patients experience breathlessness or heart failure due to the severe mitral valve leakage or if the heart function becomes impaired or if the heart chambers begin to enlarge due to the severe MR
Open chest surgical repair of the valve is preferred where possible over valve replacement as repair produces better long term outcomes. However, in many patients usually the very elderly or those with multiple coexisting diseases, open chest mitral valve repair or replacement carries with it a high surgical risk.
A minimally invasive option became available in 2007, where the leaky mitral valve could be “repaired” without the need for open heart surgery. Via a small incision in the groin and on a beating heart, a catheter (tube) is threaded into the heart and directed towards the mitral valve, and a clip (the MitraClip device) is applied to “catch and appose” the 2 mitral valve leaflets and reduce the leakage (MitraClip Figure).
A randomized trial showed that the in patients with symptoms due to severe MR, using the MitraClip device was safer than open chest surgery although it was less efficacious at reducing the leakage. However, symptoms and quality of life improvement were similar. Patients undergoing the MitraClip recovered faster and had a shorter hospital stay as expected.
Currently, the MitraClip therapy is used mainly in patients with symptomatic severe MR and at high risk for surgery. It could be considered in patients who truly refuse surgery but only as a last resort. For younger patients and in patients not at increased surgical risk, conventional open surgery to repair the mitral valve produces superior results and should remain the treatment option of choice.
Percutaneous Mitral Commisurotomy: A minimally invasive technique for mitral stenosis
Mitral valve stenosis (MS) is a condition where the mitral valve orifice becomes narrow. When this occurs, blood cannot flow properly from the left atrium into the left ventricle. The blood pools and distends the left atrium, and as the left atrium receives blood from the lungs, this eventually leads to congestion in the lungs. Mitral valve stenosis is caused mainly by childhood rheumatic fever. Therefore MS is common in developing countries but has become uncommon in developed countries like Singapore.
Severe MS (narrowing) leads to increasing breathlessness, atrial fibrillation (irregular chaotic heart rhythm) and heart failure. Medications can be used to relieve the symptoms and include diuretics (medications to increase excretion of fluid from the body) and drugs to slow the heart rate.
In patients with severe MS, medications are however, usually insufficient. Definitive therapeutic options include: open heart surgery to manually “split” the valve open or to replace the valve, and a percutaneous (minimally invasive) technique of “ballooning” the mitral valve. With the percutaneous approach, a small incision is made in the groin and a balloon catheter is threaded towards the heart and placed across the narrowed mitral valve. The balloon is then inflated to dilate and “split” the narrowed mitral valve leaflets (PMC figure). Studies have shown that in most patients with MS, percutaneous mitral commisurotomy (as the balloon technique is called) has been shown to produce as good symptom relief as open heart surgery but with a much faster recovery and much shorter hospital stay.
Currently, percutaneous mitral commisurotomy is the treatment of choice for patients with symptoms due to severe mitral valve stenosis. In some patients with a very damaged mitral valve, open heart surgery to replace the valve may be the only therapeutic option.