In vitro models of intracranial arteriovenous fistulas for the evaluation of new endovascular treatment materials.

BACKGROUND AND PURPOSE: The purpose of this study was to create and test an in vitro model of intracranial arteriovenous fistulas (AVFs) that simulates the geometry of human vasculature and allows realistic testing of devices used in endovascular therapy. METHODS: The models were derived from corrosion casts of the main cervicocranial arteries and veins obtained from two nonfixed human specimens. Wax copies of the casts were produced and combined to create complex models simulating various types of intracranial AVFs. Wax assemblies were embedded with liquid silicone solidified into transparent blocks containing, after wax evacuation, hollow reproductions of the original vascular trees. The models were connected to a pulsatile pump and their compatibility with various imaging techniques and endovascular treatment materials was evaluated. RESULTS: The models were compatible with digital subtraction angiography, CT, MR imaging, and transcranial Doppler sonography. They provided a realistic endovascular environment for the simulation of interventional neuroradiologic procedures. CONCLUSION: Anatomically accurate and reproducible in vitro models of intracranial AVFs provide a valuable method for evaluating new endovascular treatment materials and for teaching purposes.