ABSTRACT

The modified Hamburg classification is primarily an anatomical classification of vascular malformations, with an embryological subclassification. Using this simplified classification, physicians can make rapid assessment of the type and extent of the malformation that is helpful in management and particularly in selecting an intervention for treatment. The primary, anatomical classification distinguishes the subgroups based on predominant anatomy and includes arterial, venous, arteriovenous, capillary, lymphatic, and mixed vascular malformations. The embryological subclassification distinguishes two major groups based on the stages when abnormality in the development of the vascular system occurs. Extra-truncular malformations include a defect or arrest in the early development of the vascular system, while truncular malformations develop later in the embryo and affect major vascular channels, named arteries or veins. With progress in genetic research and the advent of effective drug therapy of vascular malformations, most elements of the Hamburg classification together with genetic classification have been incorporated into the complex, all-inclusive classification from the International Society for the Study of Vascular Anomalies (ISSVA).