Heart valve replacement surgery is performed in cases of severe dysfunction or disease to the heart valves that require the valves to be either repaired or replaced in order to maintain life.
The heart valves control blood flow from the heart to the body or from the body to the heart. The valves open to allow blood to flow through and close to prevent blood from flowing backward.
In most cases, heart valve replacement surgery requires an open heart surgical procedure. Open heart surgery is, by definition, any surgical procedure that requires the chest to be opened in order to operate. However, in some cases, the replacement surgery is able to be performed through minimally invasive surgery.
About the Heart Valves
There are four types of valves in the heart, each with its own function: aortic valve, mitral valve, tricuspid valve, and pulmonary valve.
Aortic valve: Located between the left ventricle and the aorta. In a properly functioning aortic valve, when pressure rises in the left ventricle over that of the aorta, the aortic valve opens to allow blood to exit the left ventricle and flow into the aorta
Mitral valve: This valve opens as a result of increased pressure from the left atrium as it fills with blood. When the valve opens, it facilitates passive blood flow to the left ventricle
Tricuspid valve: This valve functions to prevent blood from flowing back into the right ventricle
Pulmonary valve: When the pressure in the right ventricle rises above the pressure in the pulmonary artery, the pulmonary valve will open; it will close once the pressure in the right ventricle falls
Though each valve has a different function, they all prevent blood from flowing in the opposite direction and are essential to a fully functioning heart.
CAUSES FOR HEART VALVE REPLACEMENT SURGERY
Improperly functioning valves require repair – valves that do not properly close will allow blood to flow backward in a problem called regurgitation. In contrast, valves that do not properly open will limit blood flow to the body – this is called stenosis.
A heart valve replacement surgery may become necessary if tests prove that the changes in heart valves are beginning to significantly affect the heart’s functionality. Additional causes include an infected heart valve, the need to replace a heart valve already replaced during a previous procedure, or problems such as blood clots, infections, or bleeding. Other heart valve defects may cause extreme symptoms, such as angina (chest pains), shortness of breath, syncope (fainting spells), and heart failure. Doctors may opt to replace heart valves if there are already existing causes for open-heart surgery.
The Heart Valve Replacement Surgery
In preparation for the heart surgery, an anesthesiologist will administer general anesthesia to ensure that you are in a deep sleep and will feel no pain or other sensations during the course of the surgery. The surgical team will administer a cut approximately eight to 10 inches long down the chest before opening the breastbone to access the heart.
In most cases, a heart-lung bypass machine will take over the function of the heart during the procedure, pumping oxygen and blood through the body while the heart is stopped.
Alternately, minimally invasive surgery will utilize several much smaller cuts or a catheter through the skin.
Once the Cardiac surgeon has access to inspect the valves, they can assess whether the valve is repairable or will require replacement due to too much damage.
In the case that the valve(s) is repairable, the surgeon will likely utilize one of the following:
- Ring annuloplasty — The surgeon will sew a plastic, cloth, or tissue ring around the valve to repair the ring-like portion
- Valve repair – The surgeon shapes, trims, or rebuilds one or more valve leaflets, which open and close the valve.
If the surgeon determines that the valve has sustained too much damage and will require replacement, the surgeon will remove the existing valve and replace it with a mechanical, biological, or pulmonary valve.
- Mechanical – This type of valve is made from man-made materials, such as stainless steel or titanium metals, or ceramic. This type of valve typically has the longest longevity but requires the recipient to take blood-thinning medicine for the remainder of their life
- Biological – Biological valves are made from human or animal tissue. This type of valve lasts 12 to 15 years on average, so may require future replacement surgery, but do not require the recipient to take blood-thinning medications for the rest of their life
- Pulmonary – In this option, the surgeon will use the recipient’s own pulmonary valve to replace the damaged valve. This requires a second valve replacement to substitute the now missing pulmonary valve which is typically done using an artificial valve. This procedure, known as the Ross Procedure, is not always possible, but when it is can be ideal for patients wishing to avoid lifelong commitments to blood-thinning medications