RESUMO
Vascular malformations (VMs) are developmental abnormalities of the vascular system. Malformations may involve any segment of the vascular tree: arteries, capillaries, veins or lymphatics. High-flow arteriovenous malformations (AVMs) are associated with shunting of large amounts of arterial blood into the venous system; these lesions can have dynamic and dramatic hemodynamic manifestations, such as massive arteriolisation with gross venous engorgement, organomegaly of concerned anatomical region and high-output cardiac failure. Patients with Parkes Weber syndrome have clinically significant micro- or macrofistulous arteriovenous shunts, affecting usually one extremity. The patient has dilated, frequently visible pulsatile varicose veins and other visible signs of AV shunting. The abnormality is sporadic; it is likely a somatic mutation. There is frequent intraosseous involvement. The presence of high AV shunts differentiates Parkes Weber syndrome from Klippel-Trenaunay syndrome which is a clinical triad of capillary malformation, soft tissue and bone hypertrophy and venous and lymphatic malformations. The mutations in RASA 1 gene leads to Parkes Weber syndrome characterised by the presence of multiple, small (1-2 cm in diameter) capillary malformations mostly localized on the face and limbs. We report a case of congenital AVM of the lower limb causing cardiac decompensation. The patient was safely and successfully treated by performing a knee disarticulation.