TAVI/TAVR is a novel, innovative approach to implantation of aortic valve without actually having to open the chest in order to expose the heart.
It is designed primarily to help alleviate symptoms and improve quality of life and survival in patients with damaged or degenerated aortic valves for whom surgery risk is unacceptably high.
This is particularly true among the elderly population. As the world is growing older, the number of people of advanced age, say over 75, is rapidly increasing.
As such, valvular degeneration is becoming more and more common, especially aortic valve stenosis (degenerated and hardened valves that fail to open fully when the left ventricle contracts) that diminishes the supply of blood to the body outside of the heart, causing fatigue, fainting, dizziness and ultimately, heart failure. Although the gold standard for the treatment of this condition is still open heart surgery, this elderly group of patients often has other debilitating medical conditions apart from age, such as diabetes, stroke, chronic lung disease and others, that make a very unattractive choice.
In this high risk population, TAVI has become viable choice whereby, through a small opening in the groin, the artery in the leg is entered with a catheter pre-mounted with an artificial valve at the trip. This can be achieved by needle puncture or a small incision to open the artery.
The catheter is carefully and gradually advanced and meticulously positioned so that the valve aligns exactly with the valve ring of the natural valve. It is then deployed where it would stay, clamping down on the non-functional valve and completely excluding it from the aorta. Its function is taken over by the artificial one. This artificial valve is made of metal rings and struts that support the leaflets made of bovine pericardial tissue.
Occasionally, blood vessels in the legs are diseased or narrowed, making this entry site invalid. Here alternative access will be via auxiliary artery, the aorta itself, or in extreme cases, the apex of the heart through a small hole made surgically.
Easy as it may sound, it is actually not that simple. It requires a great deal of preparation and assessment by the whole heart team comprising cardiologists, cardiothoracic surgeon, cardiac anesthetist, sonographer, CT-physician, nurses and technologists who will each have a role to play.
The team reviews pre-operative investigation together to determine the surgical risk, suitability of the patient, access site and other aspects, which are reviewed and rehearsed again and again.
The procedure itself can take from a couple of hours to 5-6 hours, depending on the difficult of access. If all goes well, the patient stays in hospital for 3-5 days, depending upon their pre-operative risk and the actual procedure.
Each patient is then followed up at regular intervals to ensure that recovery is prompt and the desired goal of improving quality of life is achieved.
Having said that, a healthy lifestyle and other preventive measures form an integral part of this program. Risk factors such as blood pressure, smoking cessation and diabetic control are closely monitored. Regular and appropriate exercise is encouraged. This will ensure that these patients remain in good general health to enjoy their remaining years with children and grandchildren.