Blood flows between your left atrium and left ventricle through the mitral valve (MV). Normally, the sinoatrial node produces electrical impulses that travel through the atria (your heart's upper chambers) before reaching the ventricles (the lower chambers). The impulses trigger contractions. As the left atrium contracts, blood is sent through the mitral valve. The valve opens and allows blood to flow through, then closes to prevent backflow from the ventricle.
The MV can malfunction by narrowing (called stenosis) or leaking (referred to as regurgitation). Both problems can be caused by congenital defects, disease, or rheumatic fever. A regurgitant mitral valve may also be caused by coronary artery disease. Below, we'll take a look at mitral valve repair for both stenosis and regurgitation. We'll also explain why repairing the valve is usually preferable to replacing it.
How Narrowing Is Resolved
Mitral stenosis, whether due to a congenital defect or rheumatic fever, is characterized by the valve's flaps (or leaflets) being fused together. Because the opening between the atrium and ventricle is narrowed, the atrium is forced to work harder than it should to propel blood into the ventricle. The condition is not immediately life-threatening, but can eventually lead to heart failure.
When the MV suffers stenosis, a procedure called mitral commissurotomy can be performed. It can be done through open surgery (i.e. cutting through the breastbone) or by catheterization. In the latter case, a balloon is affixed to a catheter which is threaded to the mitral valve. Once the catheter arrives at the site, the balloon is inflated and stretches the valvular opening.
How Regurgitation Is Resolved
Regurgitation is more common than stenosis. It is often due to a cleft in the valve (also called leaflet prolapse). Because the valve fails to completely seal the opening between the left atrium and left ventricle, blood can leak from one chamber to the other (in both directions). In many cases, the cleft can simply be sewn closed, thereby resolving the leakage.
Another approach is annuloplasty. The valve's leaflets are naturally attached to the heart by a ring-shaped annulus. Annuloplasty is a procedure during which a surgeon positions a synthetic ring around the annulus to provide support for the leaflets.
Advantages Of Repairing Over Replacing
There are circumstances in which the mitral valve is so defective or damaged that it cannot be repaired. In such cases, it must be replaced. That said, whenever possible, a surgeon will recommend repairing the valve over replacing it. There are many advantages to doing so.
For example, there is less likelihood of infection or stroke due to the absence of foreign material. There is also no need for anticoagulants, which must be taken by the patient when a replacement valve is used. Moreover, the survival rate among patients who undergo mitral valve repair is higher than the survival rate for those who receive replacements.
Mitral valve repair surgery is an effective approach for resolving stenosis or regurgitation. While valvular defects rarely present immediate danger to a patient's life, the surgery can provide an improved lifestyle.