Department of Cardiovascular Surgery, University Heart Center Freiburg-Bad Krozingen, Hugstetter Str. 55, 79106 Freiburg, Germany.
Intensive Care Med. 2012 Jan;38(1):62-8. doi: 10.1007/s00134-011-2370-6. Epub 2011 Oct 1.
Extracorporeal life support (ECLS) is used for patients with refractory heart failure with or without respiratory failure. This temporary support is provided by blood pumps which are connected to large vessels. Bleeding episodes are a typical complication in patients with ECLS. Recently, several studies illustrated that acquired von Willebrand syndrome (AVWS) can contribute to bleeding tendencies in patients with long-term ventricular assist devices (VAD). AVWS is characterized by loss of the high molecular weight (HMW) multimers of von Willebrand factor (VWF) as a result of high shear stress and leads to impaired binding of VWF to platelets and to subendothelial matrix. Since ECLS and VAD share several features, we investigated patients with ECLS for AVWS.
We analyzed 32 patients with ECLS and 19 of them without support. To diagnose AVWS, ratios of ristocetin cofactor activity (VWF:RCo) and collagen binding capacity (VWF:CB) to VWF antigen (VWF:Ag) were employed in conjunction with multimeric analysis.
Reduced VWF:RCo/VWF:Ag ratios were identified in 28 ECLS patients. Furthermore, VWF:CB/VWF:Ag ratios were decreased in 31 patients. HMW multimers of VWF were missing in the same 31 patients. Thus, 31 of 32 ECLS patients presented with AVWS. Twenty-two of the 32 patients suffered from bleeding complications. Without support, AVWS was not detectable in any analyzed patient.
Our data indicate that AVWS is a typical disorder in patients with ECLS. We hypothesize that AVWS could contribute to aggravation of bleeding tendencies in ECLS patients.
体外生命支持 (ECLS) 用于治疗伴有或不伴有呼吸衰竭的难治性心力衰竭患者。这种临时支持是通过与大血管相连的血液泵提供的。出血事件是 ECLS 患者的一种常见并发症。最近，几项研究表明，获得性血管性血友病综合征 (AVWS) 可导致长期心室辅助装置 (VAD) 患者的出血倾向。AVWS 的特征是由于高剪切应力导致 von Willebrand 因子 (VWF) 的高分子量 (HMW) 多聚体丢失，从而导致 VWF 与血小板和内皮下基质的结合受损。由于 ECLS 和 VAD 具有许多共同特征，我们调查了接受 ECLS 治疗的患者的 AVWS 情况。
我们分析了 32 名接受 ECLS 治疗的患者和 19 名未接受支持的患者。为了诊断 AVWS，我们结合多聚体分析，使用瑞斯托霉素辅因子活性 (VWF:RCo) 和胶原结合能力 (VWF:CB) 与 VWF 抗原 (VWF:Ag) 的比值来诊断。
我们在 28 名 ECLS 患者中发现 VWF:RCo/VWF:Ag 比值降低。此外，31 名患者的 VWF:CB/VWF:Ag 比值降低。在相同的 31 名患者中，VWF 的 HMW 多聚体缺失。因此，32 名 ECLS 患者中有 31 名存在 AVWS。32 名患者中有 22 名发生出血并发症。在没有支持的情况下，在任何分析的患者中均未检测到 AVWS。
我们的数据表明，AVWS 是 ECLS 患者的一种典型疾病。我们假设 AVWS 可能导致 ECLS 患者出血倾向加重。
