BACKGROUND: Historically, the surgical implantation of a mechanical valvein the descending aorta permitted the reduction of regurgitant flow in chronic aortic insufficiency.Long term clinical results were excellent but with the development of the pump oxygenators, orthotopicvalvar replacement has become the conventional treatment of aortic valve diseases. We wanted to reconsiderthe ectopic position in sheep using a new percutaneous technique. MATERIAL/METHODS: A biological valveharvested from a bovine jugular vein was sutured into a vascular stent. After the creation of a severeaortic insufficiency, the valved stent was percutaneously implanted according to standard stent placementtechniques. Hemodynamic and angiographic evaluations were carried out during the procedure; finally,anatomic evaluation was performed. RESULTS: A severe aortic insufficiency was created in all animals(9/9). 3 had a single stent in the descending aorta and 3 had an additional stent in the brachiocephalictrunk. A control group of 3 animals had no valve implantation. One sheep had an additional valve implantbecause one overdilated stent had become insufficient. Early evaluation of the implanted valve functionconfirmed the perfect competence of 9 out of 10 valved stents. However, for unknown reasons all the animalsdied within 24 hours after the procedure. CONCLUSIONS: Percutaneously implanted valves in the thoracicaorta of sheep with massive aortic insufficiency function well in the acute study. In comparison to previoussurgical results, this technique might become an alternative to surgery in patients with chronic aorticinsufficiency in whom perioperative risks are high.

Keywords: Aorta, Thoracic, Aortic Valve Insufficiency, Balloon Dilatation, Bioprosthesis, Cattle, Heart Valve Prosthesis, Heart Valve Prosthesis Implantation, Hemodynamic Processes, Prosthesis Design, Research Support, Non-U.S. Gov, Sheep, Stents