Acknowledgments
Five of the authors of this publication are members of the Vascular Anomalies Working Group (VASCA WG) of the European Reference Network for Rare Multisystemic Vascular Diseases (VASCERN) - Project ID: 769036. This work was supported in part by the Center for Vascular Anomalies, Freiburg Center for Rare Diseases. F.G.K. was supported by an EXCEL-Fellowship of the Faculty of Medicine, University of Freiburg, funded by the Else–Kröner–Fresenius–Stiftung.