PTMC is a semi-invasive procedure where a balloon is used to dilate the already narrowed mitral valve.

Indication

Treatment for mitral stenosis.

Mitral stenosis is a condition whereby the mitral valve (one of the 4 valves of the heart) becomes narrowed. It is a long-term complication of rheumatic fever. While rheumatic fever is becoming rare in the developed western world, in developing countries this is still a major health issue.

Preparation for PTMC

The diagnosis of mitral stenosis is made by using trans-thoracic echocardiogram. When PTMC is planned, the patient has got to trans-esophageal echocardiogram (TEE) to ensure that there was no clot in the left atrium. If the patient is on warfarin (coumadin), they have to stop the medication about 4 days before the procedure, and may be required to be admitted the day before the procedure to receive intravenous heparin.

How is PTMC done?

The procedure is carried out in the cardiovascular laboratory. The patient will be prepared the same way as PTCA. However, this procedure can only be carried out through the groin approach. Both the femoral vein and artery will be punctured and one sheath will be inserted through each vessel. A long pigtail catheter will be positioned in the left ventricle the same way as a coronary angiogram. Then a long puncture needle will be placed at the right atrium through the femoral vein. The inter-atrial septum (the wall that separates the two atria in the heart) is punctured by the needle. A long coil is then passed to the left atrium through the hole punctured. A balloon-tipped catheter (Inoue balloon) is then guided through the hole created to the left atrium and from there passed through the mitral valve. With careful positioning, the Inoue balloon is inflated several times to stretch the narrow segment of the mitral valve. The entire balloon, catheter, coil and other foreign bodies will be removed. The hole created in the inter-atrial septum will usually close off by itself. Even if it is not sealed, such a small hole should not cause any problem to the heart.

The patient will need antibiotics before and after the procedure. If he is on warfarin, this medication will be continued.