Venous thrombosis and coagulation parameters in patients with pure venous malformations

Introduction: Venous malformations (VMs) are ubiquitous, low-flow vascular anomalies known to be occasionally painful due to thrombotic episodes within the lesion. The prevalence of superficial or deep vein thrombosis is unclear. Methods: A cross-sectional study among outpatients aged >= 12 years with pure VMs was performed, quantifying the prevalence of thrombosis by screening all patients with compression ultrasonography (CUS). Additionally, we evaluated whether coagulation alterations were related to thrombosis observed with CUS. Results: In total, 69 patients with pure VMs were eligible, median age was 30 years (range 12-63) and 52% were female. A total of 68 patients underwent CUS. Superficial vein thrombosis was observed in 10 (15%) cases; 1 patient had a current asymptomatic deep venous thrombosis. Residual superficial or deep thrombosis was observed in 25 patients (36%). In total, 49% had either a history or current signs of a thrombotic event and overall 10% had venous thromboembolism. In approximately 50% of the patients the D-dimer level was above 0.5 mg/l. Median P-selectin and Von Willebrand factor levels were 29 ng/ ml (interquartile range (IQR) 21-34) and 108% (IQR 83-132), respectively. No differences were observed in the coagulation parameters between the patients with and without current clots in their VM. Conclusion: This study shows that superficial or deep vein thrombosis is common among patients with a pure VM. Physicians should be aware of this high incidence, especially if other risk factors for thrombosis are present.