Carney John P, Schappa Faustich Jill, Lahti Matthew T, Ashworth Paul E, Dalmasso Agustin P, Moklyak Yuriy, Bianco Richard W
Experimental Surgical Services Laboratory, Department of Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
Abbott Laboratories, St Paul, Minnesota, USA.
J Invest Surg. 2022 Feb;35(2):371-377. doi: 10.1080/08941939.2020.1864796. Epub 2020 Dec 28.
Transcatheter aortic valve replacement (TAVR) is an effective therapy in treating high-risk patients suffering from aortic stenosis. Animal models used to evaluate safety and efficacy of TAVR devices prior to clinical use lack a stenotic aortic annulus, a critical impediment to long-term TAVR device evaluation. We sought to create a reproducible model of aortic stenosis using a modified aortic annuloplasty (MAA) procedure in sheep, followed by deployment and long-term evaluation of TAVR devices using this model.
Twelve sheep underwent the MAA procedure and were recovered. Transthoracic echocardiography (TTE) was used to monitor changes in the aortic annulus in the postoperative period. At 60 days post-MAA, Test group animals were anesthetized for TAVR insertion and Control animals underwent a necropsy. Test animals were recovered following TAVR insertion and observed for a postoperative period of 140 days.
Twelve sheep survived the annuloplasty procedure and the 60-day recovery period. Gross examination of seven Control group animals revealed the implanted annuloplasty ring segments formed hard protrusions into the aortic annulus. Five sheep in the Test group underwent successful deployment of Abbott's experimental TAVR device without evidence of migration. Examination at 140 days post-TAVR insertion showed all devices tightly anchored within the modified aortic annulus.
The MAA procedure creates stenotic segments in the aortic annulus with adequate rigidity for anchorage and long-term evaluation of TAVR devices. This represents the first model that successfully mimics human aortic stenosis and provides a clinically relevant TAVR deployment platform for long-term evaluation in sheep.
经导管主动脉瓣置换术（TAVR）是治疗高危主动脉瓣狭窄患者的有效疗法。在临床应用前用于评估TAVR装置安全性和有效性的动物模型缺乏狭窄的主动脉瓣环，这是长期评估TAVR装置的关键障碍。我们试图通过改良的主动脉瓣环成形术（MAA）在绵羊中创建一个可重复的主动脉瓣狭窄模型，然后使用该模型进行TAVR装置的植入和长期评估。
12只绵羊接受了MAA手术并恢复。经胸超声心动图（TTE）用于监测术后主动脉瓣环的变化。在MAA术后60天，对试验组动物进行麻醉以植入TAVR，对照组动物进行尸检。试验动物在植入TAVR后恢复，并观察140天的术后时间。
12只绵羊在瓣环成形术后和60天的恢复期内存活。对7只对照组动物的大体检查显示，植入的瓣环成形环段在主动脉瓣环内形成硬突起。试验组中的5只绵羊成功植入了雅培公司的实验性TAVR装置，且无移位迹象。在TAVR植入后140天的检查显示，所有装置都紧密固定在改良的主动脉瓣环内。
MAA手术在主动脉瓣环中创建了具有足够刚性的狭窄段，用于TAVR装置的锚固和长期评估。这是第一个成功模拟人类主动脉瓣狭窄并为绵羊长期评估提供临床相关TAVR植入平台的模型。
