Department of Cardiothoracic Surgery, University Medical Center Regensburg, Regensburg, Germany.
Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany.
Artif Organs. 2019 Nov;43(11):1065-1076. doi: 10.1111/aor.13513. Epub 2019 Jul 30.
Clot formation within membrane oxygenators (MOs) remains a critical problem during extracorporeal membrane oxygenation (ECMO). The composition of the clots-in particular, the presence of von Willebrand factor (vWF)-may be an indicator for prevalent nonphysiological flow conditions, foreign body reactions, or coagulation abnormalities in critically ill patients. Mats of interwoven gas exchange fibers from randomly collected MOs (PLS, Maquet, Rastatt, Germany) of 21 patients were stained with antibodies (anti-vWF and anti-P-selectin) and counterstained with 4',6-diamidino-2-phenylindole. The extent of vWF-loading was correlated with patient and technical data. While 12 MOs showed low vWF-loadings, 9 MOs showed high vWF-loading with highest accumulations close to crossing points of adjacent gas fibers. The presence and the extent of vWF-fibers/"cobwebs," leukocytes, platelet-leukocyte aggregates (PLAs), and P-selectin-positive platelet aggregates were independent of the extent of vWF-loading. However, the highly loaded MOs were obtained from patients with a significantly elevated SOFA score, severe thrombocytopenia, and persistent liver dysfunction. The coagulation abnormalities of these critically ill patients may cause an accumulation of the highly thrombogenic and elongated high-molecular-weight vWF multimers in the plasma which will be trapped in the MOs during the ECMO therapy.
在体外膜肺氧合(ECMO)过程中,膜式氧合器(MO)内的血栓形成仍然是一个关键问题。血栓的组成——尤其是血管性血友病因子(vWF)的存在——可能是普遍存在的非生理流动条件、异物反应或危重病患者凝血异常的指标。从 21 名患者的随机收集的 MO(PLS,Maquet,Rastatt,德国)的交织气体交换纤维垫上用抗体(抗 vWF 和抗 P-选择素)染色,并与 4',6-二脒基-2-苯吲哚复染。vWF 负荷的程度与患者和技术数据相关。虽然 12 个 MO 显示低 vWF 负荷,9 个 MO 显示高 vWF 负荷,最高积聚接近相邻气体纤维的交叉点。vWF 纤维/“蜘蛛网”、白细胞、血小板-白细胞聚集物(PLAs)和 P-选择素阳性血小板聚集物的存在和程度与 vWF 负荷的程度无关。然而,高负荷 MO 是从 SOFA 评分显著升高、严重血小板减少和持续肝功能障碍的患者中获得的。这些危重病患者的凝血异常可能导致高血栓形成和延长的高分子量 vWF 多聚体在血浆中的积聚,这些多聚体在 ECMO 治疗期间将被困在 MO 中。