Former first lady Barbara Bush and comedian Robin Williams made headlines recently because both underwent aortic valve replacement surgery. Although open-heart surgery sounds scary, Dr. John V. Conte, associate director in the division of cardiac surgery and a professor of surgery at the Johns Hopkins Heart and Vascular Institute, says aortic valve replacement is one of the most common procedures heart surgeons perform. Most patients can expect a full recovery.
What is the aortic valve?
It is the main valve that regulates the flow of blood from the heart's pumping chamber out to the rest of the body.
How does it become defective?
There is a lot of wear and tear on the valves. Once the protective outer layer of cells is worn off, you begin to get deposits of calcium. Over time, that causes the valves to stick together. Over time, this calcium becomes very hard and forms a stony cover over the valve. If it is stuck together, the blood doesn't flow as easily.
What causes the wear and tear on the aortic valve?
High blood pressure contributes significantly. There are other problems; people can be born with abnormal heart valves that wear out more easily. There are genetic causes as well.
What are the symptoms?
Patients can get short of breath, lightheaded or can even pass out. If you have any of those symptoms, you need to see a doctor. It can be a very insidious onset.
How is the problem diagnosed?
The doctor listens with a stethoscope and hears a murmur. Then he gets a echo cardiogram, which looks at all of the heart valves. It is like a sonogram, which women get when they're pregnant to look at the baby in the womb.
What are the treatment options?
If the problem is not too severe, the treatments are generally supportive. You take medicine to control blood pressure. Many people retain fluid, and you take a diuretic to help you get rid of the fluid. You are just trying to bide time. But over time, it is almost certain that, if you live long enough, you will need surgery.
What is involved in the surgery?
There are three ways to reach the heart: You can divide all of the breastbone, you can divide part of the breastbone, or you can cut beside the breastbone. We stop the heart and put the patient on the heart/lung machine. Once we open up the aorta, we cut out the valve, we get rid of all the calcium that has built up and sew the new valve in.
What are replacement valves made of?
There are two kinds: mechanical and biological. And there are two kinds are biological valves: one made of pig heart valve or the other made of pericardium, a leathery structure that surrounds the heart of all mammals. They treat it with chemicals to strengthen it and remove all of the animal proteins on it, and then mount it on struts. Once you put these valves in, they should last 10 to 20 years. And most people need to just take an aspirin, not blood thinners. The mechanical valves are made of metal and will last forever, but you have to take a blood thinner after the operation. That makes the postoperative care more complicated.
How do you determine who gets which kind of valve?
We look at the overall health and age of the patient. Older patients tend to get biological valves. Younger patients tend to get mechanical valves. You don't want to have to do the surgery again.
After surgery, can a person resume normal activities?
Not right away. The length of time will depend on the approach that is used. If I divide the breastbone completely, the patient cannot drive for a month and activity is restricted for eight weeks. If I do a partial, they are back to full activity in four to six weeks.
What is the prognosis for recovery after surgery?
The overwhelming majority of patients do very well. It is the second most common thing heart surgeons do. Thousands of these procedures are done every year.
What is the risk of the surgery?
The risk of any cardiac surgical operation runs the gamut from serious things like heart attack, stroke, kidney failure and dying to minor things like wound infections and needing a blood transfusion. For a healthy 65- to 70-year-old patient, the risk of having a major complication is in the low single digits. Unless you're sick and have a lot of risk factors, the risk is very, very low.