LAUSR

AVWS (acquired von Willebrand syndrome) has been reported in patients with congenital heart diseases (CHD) associated with shear stress caused by significant blood flow gradients. Its etiology and impact on intraoperative bleeding during pediatric cardiac surgery have not been systematically studied. This single-center, prospective, observational study investigated appropriate diagnostic tools of aVWS compared to multimer analysis as diagnostic gold standard and aimed to clarify the role of aVWS in intraoperative hemorrhage. A total of 65 newborns and infants aged 0-12 months scheduled for cardiac surgery at our tertiary referral center during 03/18 to 07/19 were included in the analysis. The GPIbM/VWF:Ag ratio provided the best predictability of aVWS (area under the curve (AUC) 0.81[0.75-0.86]), followed by VWF:CB/VWF:Ag ratio (AUC 0.70[0.63-0.77]) and peak systolic echocardiographic gradients (AUC 0.69[0.62-0.76]). A cutoff value of 0.83 was proposed for the GPIbM/VWF:Ag ratio. Intraoperative high molecular weight multimer (HMWM) ratios were inversely correlated with cardiopulmonary bypass (CPB) time (r=-0.57) and aortic cross clamp (ACC) time (r=-0.54). Patients with intraoperative aVWS received significantly more fresh frozen plasma (FFP) (p=0.016) and fibrinogen concentrate (FIB) (p=0.011) compared to those without. The amounts of other administered blood components and chest closure times did not differ significantly. CPB appears to trigger aVWS in pediatric cardiac surgery. The GPIbM/VWF:Ag ratio is a reliable test that can be included in routine intraoperative laboratory workup. Our data provide the basis for further studies in larger patient cohorts to achieve definitive clarification of the effects of aVWS and its potential treatment on intraoperative bleeding.