Anticoagulation and vascular anomalies.

A State of the Art lecture titled "Anticoagulation and Vascular Anomalies" was presented at the International Society on Thrombosis and Haemostasis (ISTH) Congress in 2023. Vascular anomalies have been classified by the International Society for the Study of Vascular Anomalies into vascular tumors and vascular malformations. Although some vascular tumors, such as tufted angioma and kaposiform hemangioendothelioma, and other vascular malformations can present with coagulation aberrancies, these are not generally managed with anticoagulation. A subclassification of vascular malformations includes slow-flow vascular malformations. It is this subgroup specifically that has a high risk of venous thromboembolism (VTE) and morbidity associated with coagulopathy that may be present. In these select cases, anticoagulation may be indicated to reduce the risk of VTE, treat VTE, or manage localized thrombosis in the malformation that causes significant pain and reduced quality of life. There are established risk factors for VTE in these patients that will be reviewed. Finally, we summarize relevant new data on this topic presented during the 2023 ISTH Congress.