Zou Yu, Teng Peng, Ma Liang
Department of Cardiovascular Surgery, the First Affiliated Hospital, College of Medicine, Zhejiang University, 79 Qing Chun Road, Hang Zhou, 310003, Zhejiang Province, China.
J Cardiothorac Surg. 2021 Apr 21;16(1):101. doi: 10.1186/s13019-021-01483-1.
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.
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.
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 cm. 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.
Transcatheter mitral replacement of the new valved stent was confirmed feasible in acute preclinical models. The new stent reveals optimal design parameters.
许多二尖瓣反流患者因被认为手术风险高而被拒绝接受心脏直视手术。经导管二尖瓣置换术是高手术风险患者的一种治疗选择。本研究旨在评估一种新型自膨胀带瓣支架经心尖进行经导管二尖瓣置换术在急性动物模型中的可行性。
在急性研究中进行了8例猪实验。实施左胸切开术，并在荧光透视引导下经心尖将新型自膨胀经导管带瓣支架植入天然二尖瓣环。记录植入前后的血流动力学数据。使用超声心动图测量二尖瓣环直径和瓣膜面积。使用侵入性方法测量跨瓣和左心室流出道压力梯度。
7只动物成功进行了经心尖二尖瓣置换术；1只动物植入失败。从放置到收紧荷包缝合线定义的平均手术时间为17.14±7.86分钟。经心尖二尖瓣置换术前后的血流动力学数据在统计学分析中无差异。植入后自膨胀装置的平均直径为2.58±1.04厘米；平均功能面积为2.70±0.26平方厘米。在7个瓣膜中检测到微量至轻度的中心和瓣周漏血。跨自膨胀装置的平均压力梯度为2.00±0.82毫米汞柱；跨左心室流出道的相应梯度为3.28±1.11毫米汞柱。尸检评估证实7只动物的装置定位准确，无左心室流出道梗阻迹象。
新型带瓣支架经导管二尖瓣置换术在急性临床前模型中被证实可行。新型支架显示出最佳设计参数。
