Retrosigmoid Craniectomy for Clip Ligation of Flow-Diverted Posterior Inferior Cerebellar Artery Aneurysm

Abstract

Flow diversion (FD) has revolutionized treatment of cerebral aneurysms. Since the introduction of the Pipeline Embolization Device (PED) there has been a significant shift in the management of cerebral aneurysms with increasing emphasis being placed on use of endoluminal reconstruction as a means of long-term, durable treatment of aneurysms. Increasingly, FD stents are being used as primary treatment for aneurysms, including those who present with subarachnoid hemorrhage1. Improper use of FD stents, however, may create havoc as access to the aneurysm sac is blocked with placement of these devices. Aneurysms that are incompletely treated with FD may continue to grow and rupture. The inability to use coils or endosaccular devices for treatment of these aneurysms means the only options for treatment are placement of additional FD devices, deconstructive strategies with or without bypass or microsurgical clipping2, thereby making an aneurysm, which may have been straight forward to treat with another strategy, a complex lesion to treat with the presence of the FD stent. Although deconstructive techniques can be used for treatment of failed aneurysm occlusion with flow diversion, where possible, surgical clipping can result in the simplest, most durable solution. Herein we present a case of a patient with a posterior inferior cerebellar artery (PICA) aneurysm, who was previously treated with flow diversion using a single pipeline embolization device, without aneurysm occlusion over one year of follow-up, who was treated with retrosigmoid craniotomy and clipping of aneurysm. Nuances of the approach selection, clipping of the aneurysm and preservation of the stent are discussed.