The human heart is like a giant pump, pumping blood in and out and sending oxygen-filled blood throughout the body. When it is functioning correctly, it is a beautiful thing to behold, a perfectly-calibrated machine. But just as machines can have problems, so can the heart.
Blood flows in and out of the heart through tubes, arteries or vessels, the main one being the aorta. The flow of the blood into these tubes is controlled by valves made of three circular pieces or leaflets. When functioning properly, they come together to form a perfect seal, assuring that blood does not leak back into the heart. Two conditions affecting the aortic valve may require surgery. There is no procedure available to repair these valves, only to replace them.
Aortic Stenosis. This occurs when the aortic valve becomes narrowed. Blood pressure must increase to pump blood out of the heart and into the aorta. Doing this over and over makes the heart work harder and leads to increased muscle growth and congestive heart failure. The solution is to replace the valve to prevent the heart from failing.
Aortic Insufficiency or Regurgitation. With this condition, the valve leaflets no longer meet, and blood leaks back into the heart. The heart slowly increases the capacity of the ventricle, the left side of the heart. Over time, the heart can no longer stretch to accommodate the blood flow and the patient experiences congestive heart failure.
When the heart is damaged and can no longer pump blood effectively, the blood becomes congested in the heart, in the lungs, and in severe cases, in the rest of the body causing the following symptoms:
When medications are not effectively treating aortic stenosis, a balloon valvuloplasty may be performed. In this procedure a wire is guided into the aorta and through the narrowed valve. A balloon is placed across the valve and expanded to help open the valve. Results are usually temporary.
The standard surgical treatment is aortic valve replacement using a metal or mechanical valve, a tissue valve from either a pig or cow or a human aortic graft.
Metal valves are made of high-tech metal and are very dependable. Those who receive these valves must commit to taking anticoagulation medication to prevent them from clogging. These are usually recommended for patients younger than 50 to 60.
Tissue valves, either animal or human, work well. Because these valves are made of tissue, patients do not have to take anticoagulation medication long-term. However, tissue valves do not last as long as mechanical ones. Animal tissue is generally recommended for patients 65-70 years old, while human homografts are most frequently used for younger patients. The operation using human tissue is considered much more difficult than that with animal tissue. A procedure called TAVR (Trans catheter Aortic Valve Replacement) uses a cow stent valve and is a good option for patients who are too high risk for major heart surgery.
Aortic stenosis is usually treated with medications until the patient begins to show signs of congestive heart failure. As with aortic stenosis, three types of valves can be used: artificial, animal valve or human valve. The TAVR procedure is not used to treat aortic insufficiency.
When treating this condition, a valve may be repaired instead of replaced. The valve repair is always preferred if possible because the patient keeps his or her own valve and doesn’ t have to worry about anticoagulation medication. But of course, a tissue valve will still have the disadvantage of wearing out.
Most adult open heart surgery is performed with a vertical incision down the center of the patient’s chest and this is the typical incision for aortic valve replacement and repair, which is often performed in conjunction with coronary artery bypass surgery. It is called a full sternotomy because the incision goes down the patient’s breastbone or sternum.
This large vertical incision allows the surgeon full access to all parts of the heart and to deal with complications more easily. It may be less painful than an incision between the ribs, which is called a thoracotomy. Total recovery time is about six to ten weeks. The disadvantage of this surgery is a very visible scar.
Another option for aortic valve repair is one of two minimally-invasive approaches which feature smaller incisions.
A mini upper sternotomy starts at the top of the sternum but is only one-third to one-half as long as a full sternotomy.
A mini thoracotomy features a small 3 to 4-inch incision in the upper right chest wall, to the side of the sterum. It also features a small incision in the right of left groin to gain access to the artery and vein.
Using a minimally invasive approach generally causes less post-operative pain and offers quicker recovery time. Of course, the scars are not as apparent. The disadvantage is that minimally invasive procedures limit what can be seen by the surgeon and can hamper dealing with a complication. Not everyone is a candidate for minimally invasive surgery, namely those that have a severely dilated aorta, who are morbidly obese, have severely calicified aortas or femoral arteries, as well as patients who have had previous open heart surgery or who need more than just valve surgery.