Percutaneous valved stent implantation in the ascending aorta for the treatment of very high-risk aortic regurgitation: an animal study.

Abstract

PURPOSE: We investigated the effects of percutaneous valved stent implantation in the ascending aorta as an alternative treatment for aortic regurgitation in a canine model. MATERIALS AND METHODS: A total of 16 healthy dogs weighing an average of 18.3 &#xb1; 2.1&#xa0;kg were used for the establishment of animal models of chronic aortic regurgitation by percutaneous aortic valve perforation and balloon dilation. At 2&#xa0;mo after successful model establishment, all experimental animals underwent valved stent implantation in the ascending aorta and then were followed up for 3&#xa0;mo. RESULTS: Experimental models of chronic aortic regurgitation were successfully established in 10 dogs. Surviving dogs underwent successful valved stent implantation in the ascending aorta and were subsequently followed up for 3&#xa0;mo. The level of instantaneous aortic regurgitation at 3-mo follow-up was significantly reduced compared with that before valved stent implantation (2.4 &#xb1; 0.9 versus 10.6&#xa0;&#xb1;&#xa0;2.1&#xa0;mL/s, P < 0.05). The left ventricular ejection fraction was significantly increased (53.8 &#xb1; 4.2% versus 37.8&#xa0;&#xb1;&#xa0;3.7%, P < 0.05), and the left ventricular end-diastolic volume was also significantly reduced (30.3 &#xb1; 2.2 versus 40.1&#xa0;&#xb1;&#xa0;3.6&#xa0;mL, P < 0.05). No paravalvular leak, stroke, atrioventricular block, or other complications occurred in dogs undergoing valved stent implantation. CONCLUSIONS: Percutaneous valved stent implantation in the ascending aorta is feasible, effective, and safe as an alternative treatment for very high-risk aortic regurgitation in a canine model.