Cardiac Valve Replacement

Heart valve diseases occur due to improper functioning of the valves. Sometimes a valve does not open or does not close proper. In this condition, the blood does not flow properly and requires valve replacement. The important valves present in human body are aortic valve, mitral valve, tricuspid valve and pulmonary valve. If a valve cannot be repaired, then a heart valve replacement surgery is performed.

Heart valve replacement surgery is the replacement of heart valves with artificial valves or bioprosthesis. It is an alternative treatment to valve repair.

Valve replacement includes four procedures:

• Aortic valve replacement (AVR)
• Mitral valve replacement (MVR)
• Tricuspid valve replacement (TVR)
• Pulmonary valve replacement (PVR)

The aortic valve and the mitral valve replacements are the most common. Pulmonary and tricuspid valve replacements are uncommon in adults.

Aortic valve replacement (AVR)

It is a procedure in which a diseased aortic valve is replaced with an artificial heart valve. Many diseases affect the aortic valve; the valve can either become leaky or partially blocked. Recent aortic valve replacement procedures include open-heart surgery via a sternotomy, minimally invasive cardiac surgery (MICS) and transcatheter aortic valve replacement (TAVR).

Aortic Valve Replacement (AVR)

Surgical procedure– In Aortic valve replacement the incision is made by cutting through the sternum. After the pericardium is opened, the patient is put on a cardiopulmonary bypass machine, which is also known as the heart-lung machine. This machine performs the task of breathing for the patient and pumping their blood around while the surgeon replaces the heart valve.

The surgeon makes a cut in the aorta when the patient is on bypass and applies a crossclamp. The patient’s diseased aortic valve is removed and is replaced by a mechanical or tissue valve. After the placement of artificial valve and closing the aorta, the heart-lung machine is taken off from the patient. A transesophageal echocardiogram helps to confirm whether the new valve is functioning properly.

Mitral Valve Replacement (MVR)

Surgical procedure- General anaesthesia is given to the patient before mitral valve replacement. Incision is made horizontally under the left breast, or vertically through the sternum. After exposing the heart, cannula is placed and blood is directed to the heart-lung machine for cardiopulmonary bypass. The mitral valve is exposed by creating an incision in the left atrium. Then the valve is replaced. Left atrium is closed and cardiopulmonary bypass is removed. The patient is taken to an intensive care unit after the surgery.

Postoperative complications and risks-

The most common complication after mitral valve replacement is atrial fibrillation. The other complications are bleeding and infection.

Benefits of heart valve replacement-

The patient can engage in his or her normal activities again. The replaced new valve will help the heart to function more efficiently.
Risks associated with heart valve replacement-

Blood clot formation can occur after surgery. These clots move to the lungs and cause shortness of breath and chest pain. Arrhythmias or abnormal heart beats can happen after surgery.

Follow up care-

Regular check-ups from a heart specialist is required after the surgery. The patient is instructed good diet and regular exercise in the follow up appointments.

Pros and cons of mechanical valves used in replacement

Pro’s of mechanical valves-

• Less reoperation rates
• Lasts for lifetime
• Better survival rates

Con’s of mechanical valves-

• Changes in doses of anticoagulant medication
• Sleep disturbance due to noise of mechanical valve
• Fluctuations in INR value.