Abstract
Pain from slow-flow vascular malformations is common, attributed to localized intravascular coagulopathy (LIC), and has a negative impact on quality of life (QOL). The use of anticoagulation has been anecdotal. The objective of this study was to determine the impact of anticoagulation in slow-flow vascular malformations on QOL, pain, and/or laboratory markers of LIC. A multi-institutional, prospective, nonrandomized institutional review board-approved observational study enrolled patients with slow-flow vascular malformation-related pain for whom anticoagulation was prescribed. Patient assessments (history, Pediatric Quality of Life survey, laboratory data) occurred at study entry, 2 weeks, 4 weeks, and 12 weeks (optional) after starting anticoagulation. A total of 45 patients were enrolled, with a median age of 18 years (range, 5-59). The cohort consisted of 14 males (31.1%) and 31 females (68.9%). All patients were naive to anticoagulation, prescribed low-molecular-weight heparin (n = 2), rivaroxaban (n = 40), or apixaban (n = 3). Six patients (13%) were on sirolimus and 2 on daily aspirin before starting anticoagulation. Eleven patients (24%) experienced minor bleeding events, including 6 with heavy menstrual bleeding. Two patients experienced clinically relevant nonmajor bleeding leading to cessation of anticoagulation. D-dimer and pain scores decreased, and QOL survey scores increased, with all changes being statistically significant from baseline to 2 and 4 weeks. Patients with slow-flow vascular malformations had less pain and improved QOL scores and coagulation parameters when treated with anticoagulation. Nonmajor bleeding occurred, especially menorrhagia, in ∼24% of patients, demonstrating the need to monitor and balance risks against benefits.