Retrograde stenting through the posterior cerebral artery in coil embolization of the posterior communicating artery aneurysm

Protection techniques using stents or balloons are occasionally limited in coil embolization of wide-necked posterior communicating artery (PcomA) aneurysms in which the PcomA originated from the aneurysm neck at an acute angle. Here, we present two cases undergoing retrograde stenting through the posterior cerebral artery in coil embolization of the PcomA aneurysms. To perform retrograde stenting, a microcatheter used for stent delivery was advanced from the vertebral artery (VA) to the terminal internal carotid artery (ICA) via the ipsilateral P1 and the PcomA. The aneurysm sac was selected with another microcatheter for coil delivery through the ipsilateral ICA. Coil embolization was performed under the protection of a stent placed from the terminal ICA to the PcomA. Deployment of the stent was successful in both aneurysms treated using retrograde stenting by the VA approach. Coil deployment was performed through the jailed microcatheter at first. The microcatheter was repositioned through the stent struts later in one case and another microcatheter was inserted into the sac through the stent struts in the other case. Both aneurysms were occluded properly with the coils without procedure-related complications. By providing complete neck coverage, retrograde stenting for coil embolization in wide-necked PcomA aneurysms seems to be a good alternative treatment strategy, when the aneurysms are incorporating extended parts of the PcomA, and the PcomA and P1 are big enough to allow passage of the microcatheter for delivery of the stent. However, this technique should be reserved for those cases with the specific vascular anatomy.