A repositionable valved stent for endovascular treatment of deteriorated bioprostheses

We report our animal experience of endovascular valve replacement (VR) of failed bioprosthesis (BP) using an original delivery catheter allowing repositioning of the valved stent (VS).

Among the different devices designed for percutaneous VR, none has the potential for repositioning of a fully deployed VS.

Five sheep underwent, on beating heart, tricuspid VR with a stented BP. Prolapse of 1 leaflet was induced by tearing. For the endovascular tricuspid VR, we used a VS constructed with a nitinol self-expandable stent and a porcine stentless aortic valve. We also used an original delivery catheter, allowing repositioning of the VS through a compression or relaxation mechanism of the stent.

Epicardial echocardiography and right ventriculography showed severe tricuspid regurgitation, with a regurgitant jet extending to the inferior vena cava. After surgical exposure to the infrarenal inferior vena cava, the VS was successfully implanted inside the failed BP in all cases. Repositioning of the fully deployed VS was always possible. Echocardiographic and macroscopic studies revealed adequate VS positioning, excellent leaflet opening, and absence of any intraprosthetic or periprosthetic leak.

Endovascular VR was easily performed in sheep with failed BP in the tricuspid position. The novel delivery catheter allowed adequate repositioning of our fully deployed VS before its definitive release. One may anticipate that the safety improvement conferred by this new technology will certainly favor the development of percutaneous VR in clinical practice.