(Open Heart Surgery)
What is heart valve repair or replacement surgery?
Heart valve repair or replacement surgery is a treatment option for valvular heart disease. When heart valves become damaged or diseased, they may not function properly. Conditions which may cause heart valve dysfunction are valvular stenosis and valvular insufficiency (regurgitation).
When one (or more) valve(s) becomes stenotic (stiff), the heart muscle must work harder to pump the blood through the valve. Some reasons why heart valves become stenotic include infection (such as rheumatic fever or staphylococcus infections) and aging. If one or more valves become insufficient (leaky), blood leaks backwards, which means that less blood is pumped in the proper direction. The physician may decide that the diseased valve(s) needs to be surgically repaired or replaced.
Traditionally, repair or replacement of heart valves has involved open-heart surgery, which means that the chest is opened in the operating room and the heart stopped for a time so that the surgeon may repair or replace the valve(s). In order to open the chest, the breastbone, or sternum, is cut in half and spread apart. Once the heart is exposed, large tubes are inserted into the heart so that the blood could be pumped through the body during the surgery by a cardiopulmonary bypass machine (heart-lung machine). The bypass machine is necessary to pump blood because the heart is stopped and kept still while the surgeon performs the valve repair or replacement procedure.
Newer, less invasive techniques have been developed to replace or repair heart valves. Minimally-invasive procedures in which the incision is much smaller often mean less pain post-operatively and shorter hospital stays. Valvuloplasty is another method that may be used to treat valve stenosis in some cases.
The diseased valve may be repaired using a ring to support a person's own valve, or the entire valve may be removed and replaced by an artificial valve. Artificial valves may be mechanical (made of metal or plastic) or tissue (made from animal valves or human valves taken from cadavers).
Other related procedures that may be used to assess the heart include resting and exercise electrocardiogram (ECG), Holter monitor, signal-averaged ECG, cardiac catheterization, chest x-ray, computed tomography (CT scan) of the chest, echocardiography, electrophysiological studies, magnetic resonance imaging (MRI) of the heart, myocardial perfusion scans, radionuclide angiography, and ultrafast CT scan. Please see these procedures for additional information.
Valves of the heart:
To better understand how valvular heart disease affects the heart, a review of basic heart anatomy and valve function follows.
The heart is a pump made of muscle tissue. The heart has four pumping chambers: two upper chambers, called atria, and two lower chambers, called ventricles. The right atrium pumps blood into the right ventricle, which then pumps the blood into the lungs where wastes such as carbon dioxide are given off and oxygen and other nutrients are taken into the blood.
From the lungs, the blood flows back into the left atrium, is pumped into the left ventricle, and then is pumped through the aorta out to the rest of the body and the coronary arteries. When the atria are pumping, the ventricles are relaxed in order to receive the blood from the atria. Once the atria have pumped their entire blood load into the ventricles, they relax while the ventricles pump the blood out to the lungs and to the rest of the body.
In order to keep the blood flowing forward during its journey through the heart, there are valves between each of the heart's pumping chambers:
tricuspid valve - located between the right atrium and the right ventricle
pulmonary (or pulmonic) valve - located between the right ventricle and the pulmonary artery
mitral valve - located between the left atrium and the left ventricle
aortic valve - located between the left ventricle and the aorta