Novel stent design for transcatheter mitral valve implantation

Loger, Klaas; Pokorny, Saskia; Schaller, Tim; Haben, Irma; Frank, Derk; Lutter, Georg

doi:10.1093/icvts/ivx289

Cited by 7 publications

(7 citation statements)

References 9 publications

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“…Finally, we note that these experiments were conducted using normal porcine hearts. The normal porcine model is an established and appropriate tool for both in vitro and preclinical in vivo testing of heart valve devices, 11,12,20 but may differ from diseased human hearts in terms of anatomy and/or material properties.…”

Section: Discussionmentioning

confidence: 99%

Novel In Vitro Test Systems and Insights for Transcatheter Mitral Valve Design, Part I: Paravalvular Leakage

et al. 2018

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While transcatheter mitral valve (TMV) replacement technology has great clinical potential for surgically inoperable patients suffering from mitral regurgitation, no TMV has yet achieved regulatory approval. The diversity of devices currently under development reflects a lack of consensus regarding optimal design approaches. In Part I of this two-part study, a test system was developed for the quantification of paravalvular leakage (PVL) following deployment of a TMV or TMV-like device in pressurized, explanted porcine hearts (N=7). Using this system, PVL rate was investigated as a function of steady trans-mitral pressure (ΔP), TMV shape, and TMV-annular oversizing, using a series of "mock TMV plug" devices. Across all devices, PVL was found to approximately trend with the square of ΔP. PVL rates were approximately 0-15ml/sec under hypotensive pressure, 10-40ml/sec under normotension, and 30-85 ml/sec under severely hypertension. D-shaped devices significantly reduced PVL versus circular devices; however, this effect was diminished when the circular device was oversized to the annulus by 6mm inter-trigonal distance. In conclusion, this steady pressure, in vitro test system was effective to compare PVL performance across TMV-like designs. PVL exhibited complex dynamics in terms of its response to transvalvular pressure and TMV profile.

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Section: Discussionmentioning

confidence: 99%

Novel In Vitro Test Systems and Insights for Transcatheter Mitral Valve Design, Part I: Paravalvular Leakage

et al. 2018

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“…Transcatheter mitral valve replacement (TMVR) is currently in the early clinical stage of development with reports of several devices and delivery systems [10,11]. Although the results have been encouraging, the technique still faces many challenges due to the complex anatomy of the mitral apparatus, high ventricular pressure, and mitral annulus motion [12].…”

Section: Introductionmentioning

confidence: 99%

New stent for transapical mitral valve replacement in acute swine experiment

Zou

Teng

2021

J Cardiothorac Surg

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Background Many patients with mitral regurgitation are denied open-heart surgery due to perceived high risk. Transcatheter mitral valve replacement is a therapeutic alternative for patients at high surgical risk. This study aimed to assess the feasibility of a new self-expanding valved stent for transcatheter mitral valve replacement via apex in an acute animal model. Methods Eight porcine experiments were performed in the acute study. A left thoracotomy was performed, and the new self-expanding transcatheter valved stent was deployed under fluoroscopic guidance in the native mitral annulus via apex. Hemodynamic data were recorded before and after implantation. Mitral annulus diameter and valve area were measured using echocardiography. Transvalvular and left ventricular outflow tract pressure gradients were measured using invasive methods. Results Seven animals underwent successful transapical mitral valve replacement; the implantation was unsuccessful in one animal. The mean procedure time, defined from placement to tightening of the purse-string suture, was 17.14 ± 7.86 min. Hemodynamic data before and after transapical mitral valve replacement showed no difference in statistical analysis. The mean diameter of the self-expanding device after implantation was 2.58 ± 1.04 cm; the mean functional area was 2.70 ± 0.26 cm2. Trace-to-mild central and paravalvular leaks were detected in 7 valves. The mean pressure gradient across the self-expanding device was 2.00 ± 0.82 mmHg; the corresponding gradient across the LVOT was 3.28 ± 1.11 mmHg. Postmortem evaluation confirmed precise device positioning in 7 animals with no signs of LVOT obstruction. Conclusion Transcatheter mitral replacement of the new valved stent was confirmed feasible in acute preclinical models. The new stent reveals optimal design parameters.

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“…For instance, there exist numerous cardiac devices that require an anchoring system to be secured to the heart (e.g. leadless cardiac pacemakers, 4,11 pacemaker leads 17 or prosthetic heart valves 10 ). The complexity of mechanical anchoring systems increases further for valve repair procedures, 8,3 where the outcome also heavily depends on the operator's experience.…”

Section: Introductionmentioning

confidence: 99%

A Robot Mimicking Heart Motions: An Ex-Vivo Test Approach for Cardiac Devices

Zurbuchen

Pfenniger

Omari

et al. 2021

Cardiovasc Eng Tech

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Purpose The pre-clinical testing of cardiovascular implants gains increasing attention due to the complexity of novel implants and new medical device regulations. It often relies on large animal experiments that are afflicted with ethical and methodical challenges. Thus, a method for simulating physiological heart motions is desired but lacking so far. Methods We developed a robotic platform that allows simulating the trajectory of any point of the heart (one at a time) in six degrees of freedom. It uses heart motion trajectories acquired from cardiac magnetic resonance imaging or accelero-meter data. The rotations of the six motors are calculated based on the input trajectory. A closed-loop controller drives the platform and a graphical user interface monitors the functioning and accuracy of the robot using encoder data. Results The robotic platform can mimic physiological heart motions from large animals and humans. It offers a spherical work envelope with a radius of 29 mm, maximum acceleration of 20 m/s2 and maximum deflection of ±19° along all axes. The absolute mean positioning error in x-, y- and z-direction is 0.21 ±0.06, 0.31 ±0.11 and 0.17 ±0.12 mm, respectively. The absolute mean orientation error around x-, y- and z-axis (roll, pitch and yaw) is 0.24 ±0.18°, 0.23 ±0.13° and 0.18 ±0.18°, respectively. Conclusion The novel robotic approach allows reproducing heart motions with high accuracy and repeatability. This may benefit the device development process and allows re-using previously acquired heart motion data repeatedly, thus avoiding animal trials.

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Novel stent design for transcatheter mitral valve implantation

Abstract: This study indicates a sufficient annular fixation force of the tested transcatheter mitral valve implantation valved stent prototypes. Therefore, these mitral valved stents demonstrate a new type of mitral valved stent design.

Cited by 7 publications

References 9 publications

Novel In Vitro Test Systems and Insights for Transcatheter Mitral Valve Design, Part I: Paravalvular Leakage

Novel In Vitro Test Systems and Insights for Transcatheter Mitral Valve Design, Part I: Paravalvular Leakage

New stent for transapical mitral valve replacement in acute swine experiment

A Robot Mimicking Heart Motions: An Ex-Vivo Test Approach for Cardiac Devices

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