The human heart consists of four chambers. The two small chambers present at the top are known as atria, while the larger chambers present near the base are known as ventricles. Each of the ventricles of the heart consists of two one-way valves, one of which controls the blood flowing into the ventricle, while the other controls the blood flowing out of the ventricle. The aortic valve controls the flow of blood out of the left ventricle into the aorta, which is the largest artery in the body. It is the aorta from where oxygenated blood reaches all parts of the body. Thus, the valve opens to allow passage of blood from the heart into the aorta, and then closes to restrict blood from leaking back into the heart. Aortic valve replacement is required in case of a heart disease that is characterized by stenosis (narrowing of the valve) or regurgitation (leaking of the valve).
Types of Valves
- Tissue Valves: These valves are developed from animal tissues, that is, either from animal heart valve tissue, or from animal pericardial tissue. Initially, they are treated, so as to prevent rejection and calcification. However, there are alternatives to animal tissue valves like a homograft, which is a human valve taken from a donor or human heart transplant recipient whose replaced heart had a healthy aortic valve. Their durability is probably the same as that of porcine tissue valves. According to the Ross procedure of replacement, at times, the valve is removed and replaced with the affected person's own pulmonary valve.
- Mechanical Valves: Mechanical valves are those valves that are supposed to outlast the affected people, and have typically been stress-tested to last for over a hundred years. Despite the fact that mechanical valves are long-lasting, there is an increased risk of blood clots associated with them.
The Aortic Replacement Surgery
Median sternotomy is used most frequently for aortic valve replacement surgery
, wherein the incision is made by cutting through the sternum (breastbone). Once the pericardium, which is the outermost layer of the heart, has been opened, the affected person is placed on a cardiopulmonary bypass machine, which is also referred to as the heart-lung machine. This machine helps the affected person in breathing, and pumps the blood to all parts of the body, while the surgeon replaces the heart valve.
Once the affected person is on bypass, an incision is made in the aorta and a cross clamp is attached. The surgeon then removes the diseased valve, and a mechanical or tissue valve is placed in that location. Once the valve is in place and the aorta has been closed securely, the patient is slowly taken off the heart-lung machine. Transesophageal echocardiogram
, which is an ultrasound of the heart done through the oesophagus, can be used to verify whether or not the new valve is functioning properly. Pacing wires are usually put in place, so that the heart can be manually paced in case of any complications after aortic valve replacement surgery. Drainage tubes are also inserted so as to drain fluids from the chest and pericardium. These are usually removed within 36 hours while the pacing wires are left in place until just before the affected person is discharged from the hospital.
As a part of the recovery, immediately after the replacement of the valve, the affected person will need to stay in a cardiac surgery intensive care unit for 12 to 36 hours. After this, the affected person is generally moved to a cardiac surgery
ward. Total time spent in the hospital following surgery is usually around a week, unless post surgical complications arise. Complete recovery from aortic valve replacement surgery will take about one to three months, provided the person with the condition takes proper care. The affected person is advised not to do any heavy lifting for around two months following surgery, so as to avoid damaging the sternum while it heals.
The aortic valve replacement success rate is quite high, as each year around 200,000 valves are replaced worldwide, with a success rate at around 98%. Thus, the life expectancy is also quite high, as a person can go on to live a perfectly long and healthy life, provided he takes care of his health by regularly exercising and eating right
Once upon a time, heart disease
was a devastating diagnosis, but with the tremendous advancements in medicine, there are plenty of new treatments available that extend the lives and continuing to provide better quality of life. When facing an Aortic Valve Replacement Surgery, take a look at all the options and understand that doctors have make great strides in repairing the damage to the heart