Department of Cardiothoracic Surgery, Royal Brompton Hospital, Faculty of Medicine, Imperial College, UK.
Eur J Cardiothorac Surg. 2011 May;39(5):643-52. doi: 10.1016/j.ejcts.2010.08.013. Epub 2010 Sep 17.
Stentless aortic valve replacement has potential benefits in terms of valve hemodynamics and clinical outcomes, although these may be offset by greater technical complexity of implantation with longer cardiopulmonary bypass and cross-clamp times compared with stented valves. Meta-analyses of the small number of published randomized trials have been limited by their lack of critical synthesis of the literature, including evaluation of the Risk of Bias. Our objective was to determine whether stentless aortic valves increase perioperative risk of mortality. We also examined secondary clinical outcomes of neurological, renal and respiratory complications as well as hemodynamic changes reported by studies following implantation of the two types of aortic prosthesis. The methodology used to answer this question was a rigorous meta-analysis of randomized controlled trials, using bias-assessment techniques designed to address limitations of conventional meta-analysis. Our findings show that many of the existing randomized trials have a high or uncertain risk of bias. Analysis of studies with low risk of bias reveals that stentless valves do not increase perioperative risk in terms of 30-day mortality and morbidity though neither do they exhibit benefits in hemodynamics or clinical outcomes compared with stented valves. Larger, more stringent randomized studies would be required to identify any robust clinical difference.
无支架主动脉瓣置换术在瓣膜血流动力学和临床结果方面具有潜在的益处，尽管与带支架的瓣膜相比，其植入的技术复杂性更高，体外循环和主动脉阻断时间更长，可能会抵消这些益处。对少数已发表的随机试验的荟萃分析受到文献综合不足的限制，包括对偏倚风险的评估。我们的目的是确定无支架主动脉瓣是否会增加围手术期死亡率。我们还检查了神经、肾脏和呼吸并发症等次要临床结果，以及两种主动脉假体植入后研究报告的血流动力学变化。回答这个问题的方法是对随机对照试验进行严格的荟萃分析，使用旨在解决常规荟萃分析局限性的偏倚评估技术。我们的研究结果表明，许多现有的随机试验存在高或不确定的偏倚风险。对低偏倚风险的研究进行分析表明，无支架瓣膜不会增加围手术期 30 天死亡率和发病率的风险，尽管与带支架的瓣膜相比，它们在血流动力学或临床结果方面也没有优势。需要更大、更严格的随机研究来确定是否存在任何稳健的临床差异。
