Ask Dr. Z

When choosing the code for repair of an AAA with a fenestrated device, is the code determined by the number of fenestrations or the number of stents placed in visceral arteries? The CPT code description says "including 1, 2, 3, or 4 visceral artery endoprostheses", which leads me to think the code is determined by the stents... but then how would I code a graft with four fenestrations and zero stents? My physician has done several cases where there are four fenestrations, and he only places stents in one, two, or three arteries.