Cheng Allen, Williamitis Christine A, Slaughter Mark S
Department of Cardiovascular and Thoracic Surgery, University of Louisville, Louisville, Kentucky 40202, USA.
Ann Cardiothorac Surg. 2014 Nov;3(6):573-81. doi: 10.3978/j.issn.2225-319X.2014.08.24.
Continuous-flow left ventricular assist devices (CFVAD) are currently the most widely used type of mechanical circulatory support as bridge-to-transplant and destination therapy for end-stage congestive heart failure (HF). Compared to the first generation pulsatile-flow left ventricular assist devices (PFVADs), CFVADs have demonstrated improved reliability and durability. However, CFVADs have also been associated with certain complications thought to be linked with decreased arterial pulsatility. Previous studies comparing CFVADs and PFVADs have presented conflicting results. It is important to understand the outcome differences between CFVAD and PFVAD in order to further advance the current VAD technology.
In this review, we compared the outcomes of CFVADs and PFVADs and examined the need for arterial pulsatility for the future generation of mechanical circulatory support.
CVADs offer advantages of smaller size, increased reliability and durability, and subsequent improvements in survival. However, with the increasing duration of long-term support, it appears that CFVADs may have specific complications and a lower rate of left ventricular recovery associated with diminished pulsatility, increased pressure gradients on the aortic valve and decreased compliance in smaller arterial vessels. PFVAD support or pulsatility control algorithms in CFVADs could be beneficial and potentially necessary for long term support.
Given the relative advantages and disadvantages of CFVADs and PFVADs, the ultimate solution may lie in incorporating pulsatility into current and emerging CFVADs whilst retaining their existing benefits. Future studies examining physiologic responses, end-organ function and LV remodeling at varying degrees of pulsatility and device support levels are needed.
连续流左心室辅助装置（CFVAD）是目前应用最广泛的机械循环支持类型，用于终末期充血性心力衰竭（HF）的桥接移植和目标治疗。与第一代搏动流左心室辅助装置（PFVAD）相比，CFVAD已显示出更高的可靠性和耐用性。然而，CFVAD也与某些并发症相关，这些并发症被认为与动脉搏动性降低有关。先前比较CFVAD和PFVAD的研究结果相互矛盾。了解CFVAD和PFVAD之间的结果差异对于进一步推进当前的心室辅助装置技术很重要。
在本综述中，我们比较了CFVAD和PFVAD的结果，并研究了未来机械循环支持对动脉搏动性的需求。
CFVAD具有体积更小、可靠性和耐用性更高以及生存率随之提高的优点。然而，随着长期支持时间的增加，CFVAD似乎可能有特定的并发症，且左心室恢复率较低，这与搏动性减弱、主动脉瓣压力梯度增加以及较小动脉血管顺应性降低有关。PFVAD支持或CFVAD中的搏动性控制算法对于长期支持可能有益且可能是必要的。
鉴于CFVAD和PFVAD的相对优缺点，最终的解决方案可能在于在当前和新型CFVAD中引入搏动性，同时保留其现有优势。需要进一步开展研究，考察不同搏动程度和装置支持水平下的生理反应、终末器官功能和左心室重塑情况。
