An experimental approach to reversible 'endovascular aortic valve placement'

Beating heart aortic valve (re)placement without thoracotomy would be a desirable therapeutic strategy. In the present study, the feasibility of an endovascular aortic valve (re)placement was evaluated in an animal model.

A self-expandable stent-valve and two different non-obstructive delivery devices were designed. Initially, the stent-valve was temporarily placed via surgically dissected carotid and subclavian arteries. After retrieval of the stent-valve, an endovascular resection of the native aortic valve was performed, followed by definitive stent-valve implantation. All procedures were performed under echocardiographic guidance.

Non-aortic vascular access was obtained in all animals. Via the carotid artery, the stent-valve was first placed into, and then retrieved from, the subcoronary position. Next, the native aortic valve was resected endovascularly, resulting in at least partial resection in all cases. The final step, definitive stent-valve implantation, was successful in all animals. The biological heart valve became functional after only a partial release of the stent. All animals remained hemodynamically stable after definitive implantation. Correct subcoronary position of the stent-valve was confirmed in a post-mortem examination. There was marked thrombus formation.

The study results proved the feasibility of: (i) reversible stent-valve placement with a nonobstructive technique in the beating heart; and (ii) partial endovascular resection of the aortic valve, with both procedures achieved via non-aortic access.