Aortic valve replacement is a type of surgery done for the treatment of various diseases that may affect the aortic valve, which is one of the four valves that control the blood flow through the heart. The procedure involves the removal of a damaged or faulty valve and replacing it by a new valve that is made of animal tissue or synthetic materials.
The aortic valve is present between the left ventricle (the lower left side of the heart) and the aorta (the largest artery in the body). The function of the aortic valve is the maintenance of blood flow outwards from the heart to the other parts of the body.
Aortic valve replacement surgery is a major operation, and recovery may take a long time.
Types of Aortic Valve Replacements:
There are two types of aortic valve replacements:
1. Mechanical valves:
They are made up of metal, carbon, or plastic. They can last for a long time, but they increase the risk of developing blood clots. Blood-thinners will be prescribed by your doctor to be taken for the rest of your life. The dosage of the blood-thinning medications is closely monitored by the doctor, as too little will not help in preventing blood clots, and an increased dose could lead to heavy bleeding following an injury.
2. Biologic valves:
These types of valves are obtained from animal tissue. They can last for 10 to 20 years, which is not as long as the mechanical valves. These valves do not cause blood clots, and blood thinners will not be required.
Purpose: The aortic valve may need replacement in the following cases:
1. Aortic valve regurgitation:
This condition is seen when the blood flows backward through the aortic valve into the left ventricle every time the ventricle relaxes, instead of flowing in a unidirectional manner from the ventricle to the aorta.
The backflow can occur due to a leaky or dysfunctional valve, which could be due to an abnormal shape of the valve which may be congenital (present at birth), deterioration of the valve, or a bacterial infection.
2. Aortic valve stenosis:
The aortic valve becomes narrowed or obstructed, which makes it difficult for the heart to pump blood into the aorta.
This can occur due to a congenital heart disorder, thickening of the valve’s closure flaps, or due to inflammatory changes that occur due to rheumatic heart disease (a condition in which the heart valves get damaged permanently).
3. Congenital heart disease:
This condition may cause aortic valve stenosis or regurgitation, and may also result in other disorders that may prevent the aortic valve from functioning properly.
For example, an individual who is born with an aortic valve not having enough cusps or tissue flaps, atresia (absence of an opening to allow normal blood flow), wrong shape or size of the valve.
Symptoms of Aortic Valve Disease:
Most people having an aortic valve disease are not symptomatic, even when leak (insufficiency) or narrowing (stenosis) is severe.
However, sometimes the following symptoms could indicate the presence of an aortic valve disease, which may require an aortic valve replacement surgery:
Physical examination: The doctor will use a stethoscope to check for a murmur (a swishing sound heard due to abnormal or turbulent blood flow across the valve of the heart), which could indicate a possible heart condition.
Echocardiogram: This test uses an ultrasound, in which sound waves are used to produce video images of the heart. This helps in the evaluation of the structure of the heart, blood flow through the heart, and the condition of the heart valves.
Transesophageal echocardiogram: This procedure involves using a small wand-like device, known as a transducer, which is attached to the end of a tube, and inserted through the mouth, into the stomach via the esophagus (food pipe). This helps the doctor in having a closer look at the heart valves as compared to a regular echocardiogram.
Electrocardiogram: This test helps in measuring the electrical activity of the heart. It helps in detecting any heart diseases, abnormal heart rhythms, and enlarged chambers of the heart.
Chest x-ray: An x-ray helps the doctor in identifying if the heart is enlarged, which could indicate the presence of a heart valve disease. A chest x-ray also helps the doctor in evaluating the condition of the lungs.
Cardiac MRI: Some magnetic fields and radio waves are used to create detailed images of the heart. It helps in determining the size and function of the lower chambers of the heart, and assesses the severity of the condition.
Stress tests or exercise tests: The different exercise tests help in monitoring the response of the heart to physical exertion, and measuring your activity tolerance.
Cardiac catheterization: A thin tube known as a catheter is inserted through a blood vessel in the arm or groin region, and guided to an artery in the heart. A dye is injected through the catheter to make the artery visible on an x-ray. This helps the doctor in obtaining a clear image of the arteries in your heart, and how the heart functions. It also helps in measuring the pressure inside the chambers of the heart.
Aortic valve replacement surgery is done under general anesthesia (the patient is put to sleep during the procedure), and can be performed in the following ways:
1. Traditional Open-Heart Surgery:
A 6 to 8-inch incision is made by the surgeon in the chest region. The incision is made to split open the breastbone.
The heart of the patient is stopped, and a heart-lung (bypass) machine takes over the heart’s function, that is, of pumping blood during this time. The surgeon then replaces the damaged heart valve using a mechanical or biological valve. The patient’s heart function is then restarted and the chest is closed using stitches or sutures. The surgery takes approximately two to fours to complete.
2. Minimally Invasive Aortic Valve Surgery:
The surgeon makes small incisions of 2 to 4 inches without opening the whole chest. A J-shaped incision is made to keep the chest region stable. The surgeon then carries out the procedure of aortic valve replacement. A minimally-invasive surgery has an advantage over open-heart surgery, as it leads to less blood loss, less trauma, less pain, and has a rapid recovery.
3. Transcatheter Aortic Valve Replacement (TAVR) procedure:
This procedure involves the use of a thin tube that runs up from a tiny opening in the leg to the heart. This tube is used by the surgeon for the replacement of the aortic valve.
The risks associated with an aortic valve replacement surgery are:
Blood clot formation
Bleeding
Infection
Heart rhythm may get irregular once in a while
Stroke (a condition in which the blood supply to the brain gets interrupted)
New valve does not work properly
New valve wears out over time
Kidney problems
Contact your doctor if the following signs are observed after the surgery:
Fever of 100.4 F or more
Pus discharge from the wound
Swelling, pain, or redness around the wound gets worse
Shortness of breath, which may get worse
Chest pain
Dizziness
In the case of minimally invasive surgery, recovery will take only a few days.
In case of open-heart surgery, recovery will take more time.
It is normal to have soreness, swelling, and redness after the surgery.
You may have a loss of appetite, sleep disturbances, and weakness after the procedure. These symptoms usually get better with time.
The breastbone takes about six to eight weeks to heal.
Avoid strenuous activities and heavy lifting for a few weeks after the surgery.
It may take approximately three months before you can resume your normal physical activities, although you can resume a desk job after six to eight weeks.
The doctor may recommend cardiac rehab or an exercise program to help you feel better.
MS, DNB (Cardio Thoracic) - Surgical Cardiologist/Heart Surgeon