An in vivo arteriovenous malformation model in swine: preliminary feasibility and natural history study.

PURPOSE To assess the feasibility, natural history, and preliminary physiologic validation of creating an in vivo arteriovenous malformation model in swine. METHODS A transorbital puncture technique into the cavernous sinus was used to create an arteriovenous communication between the rostral rete and the cavernous sinus in eight swine. Short-term patency and hemodynamic behavior were assessed clinically and by serial angiography. Acute phase physiologic characterization of four models was also performed, using intravascular pressure and Doppler blood flow velocity measurements. RESULTS Large arteriovenous shunts between the rostral rete and cavernous sinus were consistently produced, which mimicked the angiographic features of cerebral arteriovenous malformations in humans. Classic changes in intraarterial and intravenous pressures and blood flow velocities were also observed. Early pathophysiologic evolution occurred in two animals, consisting of recruitment of previously unseen collateral vessels. Spontaneous occlusion of the arteriovenous shunt occurred in most animals within 7 days because of a rigorous fibroblastic response. CONCLUSIONS A simple technique for creating an arteriovenous malformation model in swine is now possible and is promising for future studies.