Transcatheter Aortic Valve Implantation: from Experiment to Clinical Practice and Beyond

Abstract

The aim of this thesis is to understand the early and midterm safety and effectiveness of transcatheter aortic valve implantation (TAVI) for high or prohibitive surgical risk patients with severe aortic stenosis. Temporary transcatheter heart valves: The concept of transcatheter-based treatment of valvular heart disease can be dated back to 1965. At that time, Davies described a cathetermounted valve for the temporary relief of aortic insufficiency and tested it in dogs (Davies H. Lancet 1965;1 :250). A cone-shaped valve was attached to a 5-F catheter and positioned in the Hufnagel position (descending aorta). The extending catheter was fixed outside the body to the skin of the leg. The parachute-like valve collapsed and opened during antegrade systolic and retrograde diastolic blood flow, respectively. The intention was to use the device as a "bridge" to surgery while providing temporary relief of symptoms and signs of aortic insufficiency. Over the next 25-30 years, a number of investigators described similar transcatheter devices, positioned in either the descending or ascending aorta, for the temporary relief of aortic insufficiency.