Beating-Heart Surgery for Heart Valve Replacement

描述（由申请人提供）：美国每年有超过115,000名患者需要用人工设备替换患病的心脏瓣膜。虽然生物假体瓣膜被认为是理想的，但它们在大约15年内就会磨损，因此主要用于那些预计不会比瓣膜更长寿的老年人。年轻患者接受更耐用的机械瓣膜，但需要长期抗凝。这使得患者无法参加大多数运动，并使患者面临致命出血和中风的风险增加。VXi正在开发一种由两部分组成的心脏瓣膜，包括一个永久性的底座和一个插入式的可交换生物假体组织。因此，VXi装置是一种不需要抗凝血的终身生物假体瓣膜系统。当小叶套开始出现磨损的迹象时，可以使用微创无泵心脏跳动手术快速更换。快速、微创的小叶交换术大大减少了重做手术的时间，并消除了对初始人工瓣膜进行技术要求高和潜在危险的再次切除的需要。当小叶组交换时，对接站保持原位，避免破坏主动脉根部和附近的心脏传导系统。VXi已经成功地开发了瓣膜的原型，并在慢性动物模型中证明了它们的互换性。在这个快速通道申请中，我们建议开发(i)用于微创、无泵、心脏跳动手术的心脏瓣膜置换术的工具和技术，以及（ii）初始对接站的完全经根尖植入。瓣膜植入和小叶交换的工具是从我们现有的开放手术工具集发展而来的。通过尖端进入瓣膜将通过一种由Gerard Guiraudon博士首创的新型可折叠端口技术。与传统的套管针不同，我们的引入器技术可以通过灵活的心脏端口插入多个工具，从而实现高度的关节和快速的工具交换。我们建议发展跨根尖对接站、端口和交换工具技术，并在幼年羊模型上进行一系列急慢性瓣膜交换实验，评价其功能。

DESCRIPTION (provided by applicant): Each year, over 115,000 patients in the US need to have their diseased heart valves replaced with artificial devices. Although bioprosthetic valves are considered ideal, they wear out in about 15 years and are thus used primarily in the elderly who are not expected to outlive the valve. Younger patients receive mechanical valves that are more durable, but require chronic anticoagulation. This makes participation in most sports impossible and exposes the patient to increased risk for fatal bleeds and strokes. VXi is developing a two-part heart valve consisting of a permanent base and a plug-in exchangeable bioprosthetic tissue leaflet set. The VXi device is thus a lifetime bioprosthetic valve system that does not require anticoagulation. As the leaflet set begins to show signs of wear it can be exchanged rapidly, using a minimally invasive off-pump, beating heart procedure. Rapid, minimally invasive leaflet exchange significantly reduces the duration of redo surgery and eliminates the need for the technically demanding and potentially dangerous re-excision of the initial prosthetic valve. As the leaflet set is exchanged, the docking station remains in place, avoiding disruption of the aortic root and the nearby conduction system of the heart. VXi has successfully developed prototypes of its valves and demonstrated their exchangeability in a chronic animal model. In this Fast Track application, we propose to develop (i) the tools and techniques for minimally invasive, off-pump, beating-heart surgery for heart valve replacement, and (ii) a fully transapical implant of the initial docking station. The tools for valve implant and leaflet exchange evolve from our existing open surgery tool set. Access to the valve through the apex will be by way of a novel collapsible port technology pioneered by Dr. Gerard Guiraudon. Unlike conventional trocars, our introducer technology enables multiple tools to be inserted through a flexible cardiac port that enables a high degree of articulation, and rapid tool exchange. We propose to develop the transapical docking station, the port and the exchange tool technology and evaluate their function in a series of acute and chronic valve exchange experiments in the juvenile sheep model. PUBLIC HEALTH RELEVANCE: The development of transcatheter valves has been the only major innovation in the heart valve field in the past 30 years. These devices provide the reduction in invasiveness, but at the price of increased strokes and other procedural complications, and much reduced durability of the valve itself. Our technology thus offers the best combination of least invasive valve implant and leaflet exchange, with the same long-term durability of established surgical valves. Once developed and adopted by the marketplace, it will improve the quality of life for the majority of the 100,000 patients suffering from heart valve disease in the U.S., and reduce the expensive treatment of complications related to long-term use of anticoagulants.