Mitral valved stent implantation: An overview

Abstract

To date, transcatheter valve implantation is limited to the replacement of pulmonary and aortic valves. The aim of this study was to analyze a valved stent for minimally invasive implantation in the mitral position. A self-expanding mitral valved stent was designed for transapical implantation. Thirty pigs underwent off-pump mitral valved stent implantation with follow-up times of 60 minutes (n = 17) and seven days (n = 13). Transesophageal echocardiography and computed tomography were used to evaluate stent function and positioning. After valved stent deployment, accurate adjustment of the intra-annular position reduced paravalvular leakage in all animals. Accurate positioning was established in all but five animals. The average mean transvalvular gradient across the mitral valve and the left ventricular outflow tract recorded immediately after deployment, six hours and one week were 1.85 ± 0.95 mmHg, 3.45 ± 1.65 mmHg, 4.15 ± 2.3 mmHg and 1.35 ± 1.35 mmHg, 1.45 ± 0.7 mmHg, 1.9 ± 0.65 mmHg, respectively. No valved stent migration, embolization, systolic anterior movement or left ventricular outflow tract obstruction was observed. The mitral valved stent can be deployed in a reproducible manner to achieve reliable stent stability, minimal gradients across the left ventricular outflow tract and adequate stent function in acute and short term experimental settings.

Key words::

• Mitral valve
• valved stent
• transapical
• beating heart
• valve surgery

Acknowledgements

We gratefully thank Christine Hass and Marion Krueger for their excellent technical assistance and Telse Baehr (VMD) for her contribution to the success of this study.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.