Vertebrobasilar artery junction aneurysm associated with fenestration.

MD, Resident, Honorio Delgado Hospital Universidad Nacional de San Augustin, Orequipa, Peru; MD, PHD, Supervisor, Head of Cerebrovacular Surgery, Division of Neurological Surgery University of Sao Paulo School of Medicine, Sao Paulo SP, Brazil; MD, Resident, Division of Neurological Surgery University of Sao Paulo School of Medicine, Sao Paulo SP, Brazil; MD, PHD, Chairman and Director, Division of Neurological Surgery University of Sao Paulo School of Medicine, Sao Paulo SP, Brazil. Fenestration of an intracranial artery is a rare occurrence. After the vertebral artery, the basilar artery is the second most frequent site of fenestration of intracranial arteries. Alike arterial bifurcations, fenestrations resulting from developmental anomalies have a tendency to develop aneurysms. Fenestration of the proximal basilar artery aneurysms located at the vertebrobasilar junction may be associated with aneurysms. Aneurysms arising from the posterior circulation are estimated to be less than 15% of all intracranial aneurysms. The morbidity and mortality of open surgery for posterior circulation aneurysms are higher than those of the anterior circulation. Endovascular treatment of vertebrobasilar junction aneurysms with Guglielmi Detachable Coils (GDC) can provide an alternative method of treatment. We present a fenestration of vertebral artery associated with intracranial aneurysm and discuss its pathogenesis and management.