SUMMARY: Flow diversion to treat cerebral aneurysms has revolutionized neurointerventional surgery. Because the addition of coils potentially increases the time and complexity of endovascular procedures, we sought to determine whether adjunctive coil use is associated with an increase in complications. Patients in the International Retrospective Study of Pipeline Embolization Device registry were divided into those treated with the Pipeline Embolization Device alone (n ϭ 689 patients; n ϭ 797 aneurysms; mean aneurysm size, 10.3 Ϯ 7.6 mm) versus those treated with the Pipeline Embolization Device and concurrent coil embolization (n ϭ 104 patients; n ϭ 109 aneurysms; mean aneurysm size, 13.6 Ϯ 7.8 mm). Patient demographics and aneurysm characteristics were examined. Rates of neurologic morbidity and mortality were compared between groups. The Pipeline Embolization Device with versus without coiling required a significantly longer procedure time (135.8 Ϯ 63.9 versus 96.7 Ϯ 46.2 min; P Ͻ .0001) and resulted in higher neurological morbidity (12.5% versus 7.8%; P ϭ .13). These data suggest that either strategy represents an acceptable risk profile in the treatment of complex cerebral aneurysms and warrants further investigation.

BACKGROUND AND PURPOSE:The rate of PICA occlusion after flow-diverting stent placement for vertebral and vertebrobasilar artery aneurysms is not known. The purpose of this study is to determine the medium-term rate of PICA patency and risk factors for occlusion after such aneurysm treatment.