Classification of venous malformations in children and implications for sclerotherapy

The purpose of this work is to present a simple and descriptive classification system for venous malformations (VMs) that may serve as a basis for interventional therapy, and to test its usefulness in a sample of consecutively referred paediatric patients. The classification system we developed includes four types: type I, isolated malformation without peripheral drainage; type II, malformation that drains into normal veins; type III, malformation that drains into dilated veins; and type IV, malformation that represents dysplastic venous ectasia. The system was prospectively tested using phlebography in a sample of 43 children and adolescents with VMs who were referred for treatment during a 10-month period. Our hypothesis was that the type of VM would determine whether low-risk sclerotherapy was indicated. Thirteen (30%) patients had a type-I VM, 16 (37%) had a type-II, 9 (21%) had a type-III, and 5 (12%) had a type-IV malformation. In more than 90% of patients with a type-I or type-II lesion, sclerotherapy could be performed without any problems. In one third of patients with a type-III VM, sclerotherapy had to be withheld and one of nine (11%) developed a severe complication after therapy. Of the five patients with type-IV lesions, three (60%) had to be excluded from sclerotherapy. Our initial results indicate that sclerotherapeutic intervention in patients with type-III and type-IV VMs must be carefully considered, while it can be safely performed in low-risk patients with type-I and type-II lesions. (orig.)