Vascular malformations: an update

Vascular malformations occur as a result of an arrest in the development of the vascular system. The modified Hamburg classification distinguishes arterial, venous, arteriovenous, capillary, lymphatic, and mixed vascular malformations. Each malformation is further subdivided based on anatomy and on the time when arrest in development of the embryogenesis occurred; malformations can be truncular or extratruncular. Progress in the last decade in management has been significant because of improvements in open surgical procedures and perfection of percutaneous and hybrid endovascular interventions and devices, such as balloons, stents, and stent-grafts. There has been increasing use of embolization for the treatment of malformations with coils, other particles, glue, or with endovascular placement of occlusive plugs. Absolute alcohol, detergent liquids, or foam have been used for sclerotherapy with improved efficacy. The agents are delivered percutaneously or through a catheter placed either into the feeding arteries or the draining veins. This review aims to aid vascular and endovascular specialists in staying familiar with vascular malformations. These specialists need to be able to evaluate the patients, perform treatment if appropriate, or refer complex cases to multidisciplinary vascular malformation clinics and vascular centers.