Doty D B, Cafferty A, Kon N D, Huysmans H A, Krause A H, Westaby S
The Medtronic Freestyle Multicenter Clinical Trial Centers.
J Card Surg. 1998 Sep-Oct;13(5):369-75. doi: 10.1111/j.1540-8191.1998.tb01099.x.
The Medtronic Freestyle aortic root bioprosthesis is a complete porcine aortic root to allow implantation (1) as a subcoronary valve replacement by removing graft sinus aorta, (2) as a cylinder with the sinotubular junction intact within the aorta (root inclusion), or (3) as a complete aortic root replacement. The choice among the three implant techniques depends on surgeon preference or upon the pathology encountered. The advantages and differences among the three implant techniques are examined.
The Medtronic Freestyle bioprosthesis was implanted in 1163 patients in a Food and Drug administration (FDA) clinical trial between August 1992 and October 1997. There were 21 centers in the international trial using a single data repository. Clinical data was collected prior to and at operation, at 3 to 6 months and annually. The data were compiled and statistical analysis performed at the data center.
Patients having subcoronary valve implants were older (80% > 65 years) and aortic occlusion time was about 20 minutes less than the other methods. Patients having aortic root replacement presented with more aortic valve insufficiency (20%). Pathology of the aortic root and ascending aorta requiring repair was 26%, and larger (27 mm) valves were used in 40% of patients. Risk of operation was lowest (5.0%) with subcoronary valve implants and highest (11.7%) with root replacement technique. Thromboembolism was higher, early and late, with root inclusion (3.0, 3.9%/patient per year) and root replacement (3.2, 3.0%/patient per year) than for subcoronary implants (1.8, 1.6%/patient per year). There were more patients taking warfarin at the 4-year point with root inclusion (20%) or root replacement techniques (24%) than among patients having subcoronary implants (14%). Explants of the valve occurred in 2% of patients, none of whom had aortic root replacement.
The Medtronic Freestyle bioprosthesis is an effective and versatile device for replacement of the aortic valve. It offers implant techniques that can treat the aortic root pathology encountered at surgery and allows the operation to proceed according to surgeon preference.
美敦力自由式主动脉根部生物假体是一个完整的猪主动脉根部，可用于以下几种植入方式：（1）通过切除移植的主动脉窦作为冠状动脉下瓣膜置换；（2）作为主动脉内窦管交界处完整的圆柱体（根部植入）；（3）作为完整的主动脉根部置换。三种植入技术的选择取决于外科医生的偏好或所遇到的病理情况。本文对三种植入技术的优缺点及差异进行了研究。
在1992年8月至1997年10月的一项食品药品监督管理局（FDA）临床试验中，1163例患者植入了美敦力自由式生物假体。国际试验中有21个中心使用单一数据存储库。在手术前、手术时、3至6个月及每年收集临床数据。数据在数据中心进行汇总和统计分析。
接受冠状动脉下瓣膜植入的患者年龄较大（80%＞65岁），主动脉阻断时间比其他方法短约20分钟。接受主动脉根部置换的患者主动脉瓣关闭不全更多（20%）。需要修复的主动脉根部和升主动脉病变占26%，40%的患者使用了较大（27mm）的瓣膜。冠状动脉下瓣膜植入的手术风险最低（5.0%），根部置换技术的手术风险最高（11.7%）。与冠状动脉下植入（每年1.8%、1.6%/患者）相比，根部植入（每年3.0%、3.9%/患者）和根部置换（每年3.2%、3.0%/患者）的早期和晚期血栓栓塞发生率更高。在4年时，采用根部植入（20%）或根部置换技术（24%）的患者服用华法林的人数多于接受冠状动脉下植入的患者（14%）。2%的患者出现瓣膜取出情况，其中无一例接受主动脉根部置换。
美敦力自由式生物假体是一种有效且通用的主动脉瓣置换装置。它提供了多种植入技术，能够治疗手术中遇到的主动脉根部病变，并可根据外科医生的偏好进行手术。
