Pipeline embolization device for the treatment of vertebral artery aneurysms: the fate of covered branch vessels

Introduction Preliminary studies suggest that flow-diverting stents may be suitable for the treatment of aneurysms of the posterior circulation. The safety and efficacy of using flow-diverting stents for vertebral artery (VA) aneurysms is not well defined. Objective To examine the fate of covering the posterior inferior cerebellar artery (PICA) in patients undergoing placement of a flow-diverting stent for VA aneurysm. Methods Consecutive patients who underwent placement of a Pipeline Embolization Device (PED) for treatment of an aneurysm of the V4 segment of the VA between April 2012 and June 2015 at our institution were retrospectively evaluated. Angiograms were reviewed to determine the patency of the PICA when the vessel origin was covered by the PED. Results 11 patients with VA aneurysms who underwent treatment with the PED were identified. In each case the device covered the origin of the PICA. Follow-up angiography in eight patients demonstrated thrombosis of the aneurysm with patency of the PICA. Conclusions Flow-diverting stents can be used for the treatment of VA aneurysms. When appropriately sized to the vessel wall and positioned in the VA, the device may cover the origin of the PICA without impairing flow through the branching artery.