Why would somebody need to have surgery to fix a heart valve?
Think of the heart as a pump. Any pump needs a valve to keep the fluid going in the right direction. The heart has a number of valves and we will talk about two of them today. The first is the aortic valve, and that's the main valve that basically keeps blood from flowing back into the main pumping chamber or the left ventricle. Imagine if the valve is stuck; the heart then has to squeeze much harder to push blood through. If it's leaky, then the blood that leaks back in causes the heart to swell. So you either have a muscle builder-type of heart, or you have a heart that dilates because it's too leaky, and both conditions are not good for the heart.
At the University of Maryland we feel that a lot of progress has been made in valves that are made of tissue. A lot of people might have heard of the pig valve. We have tissue valves that are made from human parts and we have valves that are made from cow parts. They are manufactured and placed on stents that permit them to be formed in the shape of a valve.
Tissue valves are softer and more lifelike than metal valves. The relative advantage of tissue valves are that patients who receive these valves do not require a blood thinner. Blood thinners are necessary for metal valves and that's a lifelong prescription.
The reason for this is that blood clots can form if you have a metal valve, but with the tissue of more natural type valve, you're not at high risk of that. Our bodies see the metal valve as foreign. It doesn't really reject it, but clots on it. So we have to keep the blood slippery by taking a medication or a blood thinner.
Another type of valve that heart surgeons will help people with is the mitral valve. The new twist with mitral valve surgery is that instead of replacing the mitral valve, surgeons will actually go in and repair it, right?
Right. The mitral valve is the valve that stops blood from backing up in the lungs. If the mitral valve is leaky, which is the usual condition in this country when this valve goes crummy on us, the blood will go partially back up into the lung and partially back into the body. The blood going back up into the lung can cause shortness of breath, fatigue, and swelling of the legs when it gets really bad. It's a form of heart failure.
And sometimes people would need to get this replaced?
Even though we think tissue and mechanical (metal) valves are good alternatives to a very diseased aortic valve, we always like to maintain the natural valve whenever possible because that's the best thing. There are now numerous techniques that we learned that help us repair a leaky mitral valve.
And this can be done in a minimally invasive way?
Exactly. Even though the mitral valve is on the left side of the heart, believe it or not, we make a very tiny incision on the right side of the chest to fix it.
Have mitral valve repairs stood the test of time?
Yes. Every patient wants to know ‘Will I be back in for a redo?’ and nobody wants that prospect. Mitral valve repairs are durable, and about 90% of our patients that come to the University of Maryland with mitral valve problems end up with a very, very sound repair that we believe is durable.