Off-Pump Transapical Mitral Valved Stent Implantation: a Case Video
Saskia Pokorny, MSc.1, Katharina Huenges, MS1, Telse Bähr, DVM1, Matthias Gegenwart, MS1, Martin Marczynski-Bühlow, PhD1, Lucian Lozonschi, MD2, Jochen Cremer, PhD1, Georg Lutter, PhD MD1.
1University Hospital Schleswig-Holstein, Campus Kiel, Department of Cardiovascular Surgery, Kiel, Germany, 2University of Wisconsin, School of Medicine and Public Health, Department of Cardiothoracic Surgery, Madison, WI, USA.
OBJECTIVE: Implantation of a valved stent into the beating heart is a novel experimental approach to the treatment of mitral regurgitation. In this video the transapical implantation technique of a mitral valved stent in the beating heart is presented.
METHODS: A self-expanding mitral valved stent was implanted in a pig (46 kg) under general anaesthesia following a standardized protocol. The valved stent was comprised of an atrial element, a tubular ventricular body accommodating a bioprosthetic heart valve and an apical fixation system.
A lower ministernotomy was performed through a 1.5 inch skin incision, the pericardium was opened and the apex of the heart thereby exposed. Two rows of purse-string sutures were placed on the apex. The valved stent was crimped into the proximal tip of the delivery system. Following apical incision, the delivery system was inserted and advanced to midatrial position guided by real-time three-dimensional transesophageal echocardiography (TEE). The stent was deployed in a double-staged procedure and apically fixated after correct positioning.
Correct stent position was determined by evaluation of TEE images, pulmonary capillary wedge pressure (PCWP) and mitral annular plane systolic excursion (MAPSE).
Hemodynamic stability and stent function were assessed before and one hour after implantation. The thorax was closed, the pig was transferred to the animal facility and followed up after one month.
RESULTS: The stent was successfully implanted showing no paravalvular leakage (PVL). The mean transvalvular gradient of the mitral / aortic valve after implantation and after one month were 2.5mmHg / 2.0mmHg and 2.0mmHg/3.3 mmHg, respectively. The E/A ratio was stable. The pig recovered well from surgery and was fit on the post-operative day and was at good health throughout the observation period. One month follow up showed none to trace PVL, a normal EF (67%), no obstruction of the left ventricular outflow tract, a physiological MAPSE and slightly increased PCWP (post implant: 11mmHg, 1 month: 15mmHg).
CONCLUSIONS: The implantation technique of a novel mitral valved stent into the beating heart via transapical approach is presented. TEE guidance, reliable stent stability, minimal gradients and good valvular function were achieved and the pig recovered well from surgery.
Back to Cardiac Track Day Program