The aortic valve regulates blood flow between the lower left chamber (left ventricle) of the heart and the aorta. Transcatheter aortic valve insertion or TAVI involves the replacement of a damaged aortic valve without the need for open heart surgery. The replacement valve is delivered to the valve site via a catheter in a minimally invasive surgical procedure. Once the new valve is in place it permanently takes over the job of regulating blood flow.