Kaiqin Wu

and 8 more

Background: Transcatheter mitral valve implantation (TMVI) is a promising and minimally invasive treatment for high-risk mitral regurgitation (MR). The purpose of this study was to investigate the feasibility of a novel self-expanding valved stent for transcatheter mitral valve implantation via apical access. Methods: A novel self-expanding mitral valved stent system was designed and fabricated for the in vivo evaluation. It is consists of an atrial flange and a saddle-shaped ventricular body connected by two opposing anchors and two opposing extensions. During the valve deployment, each anchor is controlled by a recurrent string. TMVI was performed in ten pigs using the valve prosthesis through the apical access to verify technical feasibility. Echocardiography and ventricular angiography were used to assess hemodynamic data and valve function. The surviving pigs were sacrificed four weeks later to confirm stent deployment. Results: Ten animals underwent transapical mitral valve implantation with the novel mitral valved stent. Optimal valve deployment and accurate anatomical adjustment were obtained in nine animals. Implantation failed in one case, and the animal died one day later due to stent mismatch. After stent implantation, the hemodynamic parameter of other animals was stable and valve function was normal. The mean pressure across the mitral valve and left ventricular outflow tract (LVOT) were 2.98±0.91mmHg and 3.42±0.66 mmHg, respectively. The macroscopic evaluation confirmed the stable and secure positioning of the stents in the mitral valve. No obvious valve displacement, embolism, and paravalvular leakage were observed four weeks after valve implantation. Conclusions: This study proved that the novel mitral valved valve stent is technically feasible in animals. This device features opposing anchors, opposing recurrent strings, and saddle-like ventricular portions, providing structural design details for reducing TMVI complications. However, the long-term feasibility and durability of this valved stent need to be improved and verified.