Transcatheter Mitral Valve Replacement (TMVR) for mitral valve diseases
Transcatheter Mitral Valve Replacement (TMVR)
Transcatheter Mitral Valve Replacement (TMVR) is a rare and complex procedure performed to replace the dysfunctional or leaking mitral valve. TMVR is a nonsurgical, minimally invasive procedure performed at very few centers in India. Yashoda Hospitals Secunderabad recently performed this procedure in a 75-year-old man who was having a dysfunctional mitral valve.
Why TMVR? How is it performed?
TMVR offers a nonsurgical, minimally invasive alternative. Not all can undergo heart surgery, especially patients with co-existing diseases, and patients in old age are benefited by TMVR. Also, the patient cannot undergo surgery if the mitral valve is leaking blood backward.
Interventional cardiologist or surgeon makes an opening in the femoral vein in the groin and guides the catheter (thin tube) to reach the heart. Then, he eases the clip through the catheter and guides into the atrium (upper chamber of the heart). Once reached, the surgeon opens the clip’s arm and places them over the flaps of the mitral valve. Finally, the surgeon creates 2 small channels to prevent backflow of blood into the upper chamber. After the procedure, he leaves the clip and gentl removes the catheter.
All this procedure is performed under anesthesia. The patient is usually able to go home in one or two days after the procedure. After the procedure, the patient feels much better and has improved QoL (quality of life).
What is mitral valve and its diseases?
The mitral valve or the bicuspid valve or left atrioventricular valve lies in the heart between the left atrium and the left ventricle. The closing of the mitral valve and the tricuspid valve constitutes the first heart sound (S1). It is not the valve closure itself which produces the sound but the sudden cessation of blood flow when the mitral and tricuspid valves close.
The diseases that affect mitral valve are mitral stenosis or narrowing of the valve and mitral valve prolapse which is caused by an excess of connective tissue.
Mitral stenosis is caused by rheumatic heart disease. An uncommon cause for mitral stenosis is calcification of the mitral valve leaflets which is a form of congenital heart disease. Other causes may be, infective endocarditis where the vegetation may favor increased risk of stenosis, mitral annular calcification, endomyocardial fibroelastosis, malignant carcinoid syndrome, systemic lupus erythematosus, Whipple disease, Fabry disease, and rheumatoid arthritis, hurler’ disease, hunter’s disease and myloidosis.
Thickened mitral valve means reduced mitral valve area below 2 Sq cm causes impediment to the flow of blood into the left ventricle. This creates a pressure gradient across the mitral valve resulting in an increase in heart rate or cardiac output. It may also lead to atrial fibrillation, a condition marked by abnormal heart rhythm, heart palpitations, fainting, shortness of breath, and chest pain.
RISK FACTORS & COMPLICATIONS
The risk factors and complications are evident as mitral valve prolapse and regurgitation. Mitral valve regurgitation is a condition where the valve leaks blood back into the left atrium. The complications are also evident as heart rhythm problems (arrhythmias), and heart valve infection (endocarditis).
TESTS AND DIAGNOSIS
The doctor listens to the heart by using a stethoscope. The existence of mitral valve diseases would mean hearing of clicking sounds or a heart murmur. These sounds occur due to blood leaking backward through the mitral valve. An echocardiogram is also advised by the doctor. The echocardiogram is a non-invasive process that evaluates the condition of the heart, creates images of the heart and its structures.
Chest X-ray and Electrocardiogram also help the doctor in the diagnosis of mitral valve diseases. Any irregularities in the heart’s rhythm and structure are identified by the doctor. Under certain conditions, the stress test is advised by the doctor. Stress test includes exercise or medications to increase the heart rate. The heart is made to work harder. Any condition of mitral valve regurgitation is sure to limit one’s ability to exercise.
MEDICATIONS AND TMVR
When a significant amount of blood is leaking through the mitral valve, the consulting doctor may recommend medications and TMVR. Medications are directed at correcting the heartbeat, relax the blood vessels and improve the blood flow. Diuretics are prescribed to drain water/fluid from the lungs. The risk of blood clots is reduced by appropriate medications.
In most cases of mitral valve prolapse or other diseases, surgical treatment may not be necessary. However, in conditions of mitral valve regurgitation, there are more chances for heart failure. The doctor recommends a TMVR which involves replacing or repairing the mitral valve. The surgical procedures for mitral valve replacement or repair may be open-heart surgery or minimally invasive surgery. The latter is considered as more patient-friendly, with promising scope for lesser blood loss and quicker recovery time.