Endovascular treatment of recurrent intracranial aneurysms following previous microsurgical clipping with the Pipeline Embolization Device

Abstract

The treatment of intracranial aneurysms with microsurgical clipping is associated with a very low rate of recurrence. However, in cases of aneurysm recurrence after previous clipping, microsurgical dissection due to adhesions and fibrosis may be challenging, and it may be difficult to safely occlude the recurrent lesion without the risk of significant morbidity. Flow-diverting stents have drastically changed the landscape of endovascular neurosurgery. We present two patients with large, recurrent supraclinoid internal carotid artery (ICA) aneurysms which were previously clipped 17 and 23years ago at outside institutions. Both recurrent lesions were treated with the Pipeline Embolization Device (PED; ev3 Endovascular, Irvine, CA, USA) without radiographic or clinical complications. In the first patient, the 15mm aneurysm significantly decreased in size at 6month angiographic follow-up. The 21mm aneurysm in the second patient was completely occluded 7months following PED treatment. The moderate degree of in-stent stenosis present on initial follow-up imaging resolved on angiography 11months post-treatment. The management of recurrent aneurysms after clipping is sparsely reported in the literature due to its infrequent occurrence. In carefully selected cases, flow-diverting stents may be used for complex aneurysms of the distal ICA, even for those which have recurred following microsurgical clipping.