New classification of congenital vascular malformations (CVMs)

The congenital vascular malformation (CVM) remains a most difficult and confusing diagnostic and therapeutic clinical entity due to the wide range of clinical presentations, degree of severity, location, unpredictable clinical course and erratic response to treatment with high recurrence by its nature/pathogenesis.Despite tremendous efforts to control the CVMs through centuries, it has remained a significant challenge to clinicians and the CVM is often viewed as an enigma among the vascular disorders. Besides, old definition of the CVMs based on only the clinical findings and also the classification with name-based eponyms through the last century added more confusion and failed to provide proper information necessary for its advanced management.Through last two decades new classifications have been established to meet its mandate for the contemporary management: Hamburg Classification and ISSVA Classification. Both classifications were established based on new advanced knowledge of the anatomy, embryology and pathophysiology involved to the CVM pathogenesis as birth defects affecting entire vascular system: artery, vein, and lymphatics. The role of old classification became obsolete, no longer needed for contemporary management of the CVMs.Hamburg Classification is now able to provide safer clinical guide based on embryological characteristics of the CVM lesions depending upon the stage of embryogenesis when the developmental arrest occurs: ‘extratruncular’ type for the lesions originated from the ‘early’ classified with the potential for growth and proliferation to cause the recurrence and subsequent morbidity while ‘truncular’ type for the lesion from the’‘late’ stage with more serious hemodynamic impacts.ISSVA Classification also provides a clear guideline for the differentiation between the vascular tumor, known as hemangioma, and vascular malformation which was further subgrouped based on the flow characteristics.Therefore, correct understanding on these two new classifications are the prerequisite for proper management of every CVM lesion and correct identification and confirmation of each CVM lesion on this embryological subtype is extremely crucial for contemporary management.