Aortic mitral surgery
The heart has four valves. These are:
- Aortic valve. This is located between the lower left chamber or left ventricle and the aorta, which is the big blood vessel through which blood from the heart passes to other parts of the body. It has three flaps or leaflets.
- Tricuspid valve (also called the right atrioventricular valve). This is located between the right upper chamber and right lower chamber. It has three flaps.
- Pulmonary valve (also called pulmonic valve). This is located between the right lower chamber and the pulmonary artery. It has three flaps.
For efficient heart function, the valves must be able to open fully while the blood is passing through, then close tightly afterwards. Simply put, blood should flow only in one direction.
Abnormal or sick valves allow less blood to pass through and/or make it leak backwards. This may be due to:
- Weakened flaps
- Fusion of the flaps
- Holes or tears on the flaps
- Deformity on the valve due to scar tissue
- Hardening of the valve due to deposits that are either waxy or calcified (called plaques)
To resume efficient function, sick valves need to undergo a surgical procedure called valve repair or valve replacement.
This is the preferred treatment because results have been proven good. The faulty valve is repaired by:
- Cutting through and separating fused flaps
- Patching holes and sewing tears on flaps
- Reshaping deformed valves by removing excess tissue, scars and plaque deposits
This is done only when repair is not possible. The diseased valve is removed and replaced with either a man-made metallic valve or a biological valve (from pig, cow or human tissue).
Metal valve vs. biological (or bioprosthetic) valve
- Metal valves last longer while bioprosthetic valves need to be replaced in 10-15 years
- Persons with metal valves are maintained on lifelong warfarin (a blood-thinning medicine) while those with biological valves are not
- Metal valves are recommended for younger individuals; Bioprosthetic valves are recommended for the elderly and for women of childbearing age
Conditions that may require mitral valve repair or replacement
When the heart beats and blood in the left lower chamber, which is supposed to be pumped out towards the other parts of the body, leaks back to the left upper chamber, a condition called mitral regurgitation exists. It could be due to weak valve flaps (the mitral valve has two). Sometimes the flaps even protrude backwards, a condition known as mitral prolapse.
Mitral stenosis is a condition when the mitral valve does not fully open thereby allowing only a small amount of blood to pass through from the left auricle to the left ventricle. It could be that the flaps of the valve got stuck to each other (fused), or they may have stiffened or hardened due to scars, calcified deposits or plaques.
Conditions that may require aortic valve repair or replacement
Aortic insufficiency (also known as aortic regurgitation)
The aortic valve is unable to snugly close, allowing blood that has already flowed out to the aorta to flow back to the left ventricle of the heart. This might be due to softening or weakening, tear, or a disfigurement of the flaps.
The aortic valve is unable to open fully, thereby allowing only a small amount of blood to pass through towards the aorta. This might be due to scarring, adhesion or sticking together (fusion) of the flaps of the valve, or the presence of waxy deposits or plaques in the valves.
How the procedure is done
The procedure is performed in the operating room by a heart surgeon under general anaesthesia. Tubes for delivery of oxygen and IV fluids are hooked up and the middle part of the front of the chest is opened to expose the heart. The patient is put on heart-lung bypass machine (also called cardiopulmonary bypass pump) to ensure continuous oxygenated blood flow to all parts of the body except, of course, the heart.
Meanwhile, the heart is made to stop beating by either lowering its temperature or injecting a substance to make it stop. Actual repair or replacement of the faulty valve is done (utilizing any of the specific procedures listed under valve repair and valve replacement above).
The heart resumes its beating either by itself or through the use of mild electric shocks.
When the heart is seen to be beating normally again, the heart-lung bypass pump is withdrawn and excess blood around the operation area is suctioned off and a drainage system is set up.
The chest opening is then closed and dressed, and the surgery is considered officially over.
After heart surgery, the patient is made to recover for a few days in an intensive care unit where his vital signs are closely monitored. Once he awakens and is stronger, he is transferred to the post-surgery unit. Most often, pain medication, antibiotics and anti-coagulant are given. When the range and duration of movement and physical activity have increased (usually in 5-15 days), the patient is made to go home. In a month or two, the patient may feel stronger than he was before the operation.
Recuperating at home, the patient needs to consider certain things, such as:
- Medications. He may be made to continue certain medications for a lifetime (such as the anti-clotting medicine warfarin)
- Wound care
- Exercise and physiotherapy
- Complications to watch out for
- When to go back to work
- Check ups
- Lifestyle modifications
- Cardiac rehab
It is best to have a detailed talk with Dr Michael Harden regarding these before going home. So, make sure that all necessary contact numbers are listed down.
Nowadays, the success rate of open heart surgeries, valve repair and replacement included, has gone up. More so if the disorder or defect is corrected at a stage before severe irreversible complications have set in. Other determining factors for the success of valve repair and replacement are age (the younger the better), previous lifestyle (those who didn’t smoke, drink, and used to eat healthy diets tend to fare well), and, of course, the new lifestyle the patient chooses.