Identification of Genetic and Cellular Markers Associated With Vascular Endothelial Modifications in Cutaneous Arteriovenous Malformations

Cutaneous Arteriovenous malformations (AVM's) rare congenital high-flow vascular malformations in which arteries and veins are directly connected through a complex web of abnormal arteries and veins instead of a normal capillary network. Arterial feeders and enlarged draining veins directly connect through arteriovenous fistulas that create the "nidus". The natural history of AVMs is organized into a clinical staging system: during the first phase of quiescence, the arteriovenous malformation mimics a capillary malformation. After many years, the AVM may enlarge with loco-regional expansion and tissular destruction. At the ultimate stage, AVM may impact the heart function. They are considered non malignant but can expand and become a significant clinical risk when extensive. The management of these high flow AVM remains often problematic. Complete and large surgical excision of the nidus after hyperselective embolization is the only potential therapeutic solution but this, is often difficult if not impossible. There is no pathogenetic hypothesis for the development of these malformations. Histopathological examination (performed only on surgical resection specimen) is poor and does not provide sufficient evidence to assess the evolutivity or the severity of the MAV. Recent data hypothesize that these vascular malformations are associated with alterations of the vascular endothelium caused by genetic abnormalities involved in the control of angiogenesis and vascular homeostasis. The detection of these anomalies allows the search for cellular and genetic markers that might be useful to optimize the clinical classification, staging, predicting the evolution of these defects and some understanding of its pathophysiological mechanisms. To our knowledge, no studies to identify cellular markers / genetic and endothelial associated with the development of cutaneous AVMs have been published to date.