Clinical presentation — Arteriovenous malformation

Arteriovenous malformations (AVM) tend to progress, which usually leads to clinical manifestations of the disease in the second or third decade of life.

Superficial arteriovenous malformations typically appear as excessively warm, pulsating lesions on palpation because of the high blood flow. The overlying skin may be erythematous, very much like a capillary malformation, but it is overly warm unlike a capillary malformation. If the arteriovenous malformation is located on a limb, the palpable pulse of the supplying limb arteries is stronger on palpation − usually compared to the opposite side as well.

This increased pulsatility as well as the somewhat space-occupying character of the arteriovenous malformation can sometimes be perceived just by inspection in the advanced course of the disease. In addition, as a result of the steadily and slowly increasing blood flow through the arteriovenous malformation with increased venous pressure, dilated, superficial, drainage veins or phlebedema can also appear as venous hypertension progresses.

Sometimes tissue hyperplasia can also occur as an accompanying condition. Other possible clinical manifestations result from complications which occur in the natural course of the disease. These mainly affect the surrounding soft tissue in terms  of surrounding tissue ischemia leading to the development of gangrene, venous stasis with dilated, insufficient veins, chronic venous insufficiency with congestive dermatitis or the development of ulcers. In advanced stages, cardiac overload may become clinically manifest.

At an ISSVA meeting in 1990, Schobinger proposed a clinical classification system for arteriovenous malformations, which is still used by several experts: