Acquired von Willebrand disease in children undergoing extracorporeal membrane oxygenation: a prospective observational study

Background: Extracorporeal membrane oxygenation (ECMO) provides cardiopulmo-nary support for children with severe cardiac and/or pulmonary failure. The incidence of bleeding complications during ECMO support is high. Acquired von Willebrand disease (AVWD) might contribute to the development of bleeding complications. Objective: To study the incidence and longitudinal profile of AVWD during the first 14 days of ECMO support in children and to investigate the association between AVWD and bleeding complications. Methods: This prospective observational study included pediatric patients (0-17 years) receiving ECMO. Blood was sampled prior to and after ECMO start, daily and 12 to 24 hours after stopping ECMO. von Willebrand factor (VWF) parameters and multimer patterns were determined. Clinical data were collected for each patient. AVWD was defined as loss of high -molecular weight multimers (ie, decreased compared with baseline) or a VWF:collagen binding/VWF: antigen (Ag) ratio or VWF:activity/VWF:Ag ratio below 0.7. Results: All of 50 (100%) patients developed AVWD during ECMO. The VWF:collagen binding /VWF:Ag ratio, VWF:activity/VWF:Ag ratio, and high-molecular weight multi-mers decreased during the initial days and recovered to baseline level within 24 hours after stopping ECMO. The incidence and longitudinal profile of AVWD were similar in patients with and without major bleeding complications. Conclusion: Children receiving ECMO support commonly develop AVWD. AVWD develops rapidly after ECMO initiation and recovers quickly after ECMO cessation. Importantly, AVWD appears to be independent of major bleeding.