Vascular malformation

A vascular malformation ( vascular malformation ) is a malformation of blood or lymphatic vessels. Vascular malformations are among the most vascular anomalies. Various forms of vascular malformations include arteriovenous malformations, venous malformations, capillary malformations and lymphatic malformations. Vascular malformations are congenital, and which in the course of life is often a Größenprogredienz.

Classification

We distinguish:

• Arteriovenous malformations ( AV malformation, AVM): these are direct vascular connections between arteries and veins without capillary bed. The arterial ( oxygenated ) blood comes from an artery and flows directly into a vein, without disrupting the tissue oxygen contained therein is consumed. With the appropriate size of AVM may lead to a transfer of a considerable volume of blood that can be relevant as Steal syndrome clinically.
• Venous malformations ( VM): The VM is the most common form of vascular malformation. She has, in contrast to the AV malformations always only a small flow of blood. It is abnormally shaped and enlarged veins. The wall of this canal system is unusually thin due to a lack of smooth muscle cells, however, they are lined by endothelium. They are livid blue, blood- filled and there is no parenchyma between the vascular spaces. Often thrombi are within the Kavernomes.
• Capillary malformations: These are vascular malformations of the smallest blood vessels ( capillaries). An example of a manifestation on the skin is the nevus flammeus, in the digestive tract of Osler's disease.

Clinical Significance

Whether a vascular malformation belongs clinical significance depends on the location, size, and of a possible bleeding. AVM can be hemodynamically relevant in very strong blood flow, in addition they are bleeding risk. VM have mainly through the mass effect clinical significance, but also they can cause significant bleeding. Capillary malformations and lymphatic malformations are especially bothersome for cosmetic reasons, but mostly they are harmless.