Interventional Management of Arteriovenous Malformations

Abstract

Arteriovenous malformations (AVMs) are fast flow malformations characterized by the presence of arteriovenous shunting. These congenital lesions can be evolutive, leading to serious complications such as bleeding, skin ulceration, and cardiac failure. The interventional radiologist plays an important role in the management of these patients. He should be involved in the clinical evaluation to make the proper diagnosis, evaluate the symptoms and potential indication for endovascular treatment. This evaluation should be done in a multidisciplinary clinic with access to plastic surgeons, internal medicine and dermatologist, as well as specific specialists that might need to be implicated (ENT surgeon in the face and neck area, for example). The Schobinger clinical classification is important to assess patient evolution and indicate intervention. We recommend to treat symptomatic or evolutive AVMs. Doppler ultrasound is the first imaging examination that should be performed. Then, MR angiography or computed tomography angiography (CTA) can be proposed depending on the anatomic area involved. Embolization is currently the first line of treatment for these patients. There is currently promising research in the identification of genetic markers and molecular target(s) but there is no recognized pharmacologic treatment for AVM available yet. Digital substraction angiography (DSA) is usually performed for guidance during the embolization session but is also essential to properly classify a specific lesion, according to its anatomy. The anatomic classifications proposed by Cho and Yakes are both useful to choose the best therapeutic approach: Endovascular, direct puncture, retrograde venous approach or a combination of these techniques. Ethanol is the most efficient agent but is at higher risk of skin necrosis and nerve injury and should therefore be used with caution in dangerous territories. Glue and Onyx are liquid agents that are also well suited to occlude the nidus; they can be used in association with ethanol. On the venous side, mechanical occlusion with coils or Amplatzer plugs is mostly used. Again, they can be used in association with a liquid agent (Ethanol, glue or Onyx) to reflux in the nidus. Surgery can be indicated to resect residual AVM following embolization if residual symptoms are present and the planned surgery is feasible, with relative safety.