Cohort
Members of the American Society of Pediatric Hematology/Oncology (ASPHO) Vascular Anomalies Special Interest Group (VA SIG) were invited to participate by submitting clinical data of patients diagnosed with KHE/TA between January 2005 and January 2020 with at least 6 months of follow-up. Subjects who died within 6 months of diagnosis and met all other eligibility criteria were included. This study was IRB approved at each local institution, and patient clinical and treatment information was collected securely in a REDCap database.29 Data from each center, excluding protected health information, were adjudicated by Drs. Borst, Jeng, and Adams and sent to the coordinating center for analysis.