Experimental pseudo arteriovenous malformation. A model for training and research

There are few experimental models of arteriovenous malformations (AVM). The following study was designed to evaluate an easy-to-perform method in a canine model. Bilateral high-flow carotid to external jugular vein arteriovenous fistulae (AVF) were created in three adult dogs. 21 days after surgery one AVF was occluded by a coated stent, whereas the contralateral side remained patent. Frequent angiograms of the carotid and the vertebral arteries were performed in the nine months after surgery to investigate the effects of long-standing high-flow AVF. Because of a significant steal effect, the fistulae recruited arterial blood flow at a rapid rate from the ipsilateral vertebral artery and to lesser extent from the contralateral side, which was only disclosed after occlusion of the contralateral AVF. These cephalic pseudo AVMs were seen in all three dogs. The model presented is easy to establish and shows angioma-like morphological components comparable to human AVM. It is useful for the testing of new catheters and embolic materials as well as in the training of superselective navigation with micro catheters. However, it is unsuitable for examination of intracranial pathophysiology.