Transcatheter Aortic Valve Implantation
What is it?
Transcatheter Aortic Valve Implantation (TAVI), now being performed in clinical trials at Loyola and other hospitals in the United States, replaces a heart valve in a minimally invasive procedure that involves inserting a new valve into the heart through a catheter (a thin, flexible tube) threaded through a leg artery. Sometimes called a percutaneous valve replacement, it is an alternative to traditional open-heart surgery for patients who have severe heart valve disease and need one or more new aortic valves.
TAVI is being performed in more than 40 countries, but it is still undergoing clinical trials in the United States and is considered an investigational procedure. Therefore, it is not yet widely available. However, Loyola Hospital has been enrolling patients in a clinical trial that offers percutaneous valve replacement as an alternative to traditional open-heart surgery.
The valve device used in TAVI through the trial is a self-expanding prosthetic, tri-leaflet valve made from the pericardium (membrane enclosing the heart) of pigs with a nickel-titanium frame.
How is it done?
The CoreValve aortic prosthesis is designed to be inserted in a specialized delivery tube that is 6 millimeter in diameter. During the TAVI procedure, the delivery catheter containing the core valve is inserted into an introducing sheath. That sheath is in turn placed into the patient’s groin vessels or directly into the ascending aorta through a small 1-inch incision.
Initially a 2-centimeter diameter balloon is positioned across the diseased aortic valve and inflated to make room for the new valve. An interventional cardiologist and a heart surgeon then place the prosthetic valve directly over the diseased aortic valve; when the core valve is in the proper place, a control knob in the delivery catheter is activated, releasing it. The frame of the CoreValve expands within the aorta, firmly attaching itself to the aortic wall. Once the new valve is secured, the operators remove the delivery catheter and the new valve takes over the function of the old aortic valve. The prosthetic valve helps ensure that the oxygen-rich blood flows freely from the heart to the aorta and throughout the rest of the body.
Until this procedure has been approved for regular use in the United States, the risks and benefits cannot be adequately expressed. Once the safety and efficacy of transcatheter aortic valve implantation has been proven through clinical trials, however, it could become a new standard of care for patients who have severe aortic valve stenosis and are too high-risk for traditional open-heart surgery. There is hope that this technology could be the next great advance in the minimally invasive treatment of patients with heart disease, and Loyola is proud to be a part of the clinical trials testing its safety and effectiveness.
Because transcatheter valve replacement is a minimally invasive procedure, it may offer benefits similar to other less invasive heart procedures, including smaller incisions and less scar tissue.
Other possible benefits may include:
- Shorter hospital stays after surgery
- Reduced risk of infection
- Low risk of bleeding and the subsequent need for blood transfusions
- Shorter recovery time and faster return to normal activities