Transcatheter aortic valve implantation--update and evidence

Feasibility evaluation of the transapical saddle-shaped valved stent for transcatheter mitral valve implantation

Background and Aims of Study

Transcatheter mitral valve implantation (TMVI) is a promising and minimally invasive treatment for high‐risk mitral regurgitation. We aimed to investigate the feasibility of a novel self‐expanding valved stent for TMVI via apical access.

Methods

We designed a novel self‐expanding mitral valve stent system consisting of an atrial flange and saddle‐shaped ventricular body connected by two opposing anchors and two opposing extensions. During valve deployment, each anchor was controlled by a recurrent string. TMVI was performed in 10 pigs using the valve prosthesis through apical access to verify technical feasibility. Echocardiography and ventricular angiography were used to assess hemodynamic data and valve function. Surviving pigs were killed 4 weeks later to confirm stent deployment.

Results

Ten animals underwent TMVI using the novel mitral valve stent. Optimal valve deployment and accurate anatomical adjustments were obtained in nine animals. Implantation failed in one case, and the animal died 1 day later due to stent mismatch. After stent implantation, the hemodynamic parameters of the other animals were stable, and valve function was normal. The mean pressure across the mitral valve and left ventricular outflow tract were 2.98 ± 0.91 mmHg and 3.42 ± 0.66 mmHg, respectively. Macroscopic evaluation confirmed the stable and secure positioning of the stents. No obvious valve displacement, embolism, or paravalvular leakage was observed 4 weeks postvalve implantation.

Conclusions

This study demonstrated that the novel mitral valve is technically feasible in animals. However, the long‐term feasibility and durability of this valved stent must be improved and verified.

Cardiac Surgery: Beyond Conventional Sternotomy With Cardiopulmonary Bypass

Minimally invasive cardiac surgery options, which originated with off-pump coronary artery bypass grafting and aortic valve procedures, continue to evolve in order to address complex conditions, including those requiring mitral and tricuspid valve repair. Although these procedures are primarily indicated for high-risk patient populations, favorable patient outcomes have resulted in recommendations being expanded to include intermediate-risk groups. This article increases nursing-related knowledge of minimally invasive cardiac procedures, providing an overview of current minimally invasive cardiac surgeries and their associated risks and benefits.

In Vitro Hydrodynamic Assessment of a New Transcatheter Heart Valve Concept (the TRISKELE)

This study presents the in vitro hydrodynamic assessment of the TRISKELE, a new system suitable for transcatheter aortic valve implantation (TAVI), aiming to mitigate the procedural challenges experienced with current technologies. The TRISKELE valve comprises three polymeric leaflet and an adaptive sealing cuff, supported by a novel fully retrievable self-expanding nitinol wire frame. Valve prototypes were manufactured in three sizes of 23, 26, and 29 mm by automated dip-coating of a biostable polymer, and tested in a hydrodynamic bench setup in mock aortic roots of 21, 23, 25, and 27 mm annulus, and compared to two reference valves suitable for equivalent implantation ranges: Edwards SAPIEN XT and Medtronic CoreValve. The TRISKELE valves demonstrated a global hydrodynamic performance comparable or superior to the controls with significant reduction in paravalvular leakage. The TRISKELE valve exhibits enhanced anchoring and improved sealing. The valve is currently under preclinical investigation.

Modular aortic valve prosthesis for transcatheter aortic valve implantation: a novel concept with a new implantation method

Transcatheter aortic valve implantation (TAVI) is a relatively new medical intervention. Research on dedicated TAVI devices is an exciting and dynamic field to be explored by professionals involved in technological innovation. The authors describe in this article the first engineering concept and part of the US Patent of a new valve prosthesis. Divided into two pieces to be separately implanted using a single catheter by means of an innovative technique, this device aims at reducing prosthesis and delivery catheter profile. Miniaturization of the valve and delivery system is probably the best solution to reduce the morbidity and mortality that derive from vascular complications associated with TAVI.