Late morphological progression of a dissecting basilar artery aneurysm after staged bilateral vertebral artery occlusion: Case report

Background: The authors present a patient who experienced late (5-year follow-up) morphological progression of a dissecting aneurysm of the distal basilar artery after treatment with a combined microsurgical and neuroendovascular Hunterian strategy. In addition to postulating about the possible reasons underlying the evolution of this lesion, the role of stenting is discussed. Case Description: The patient was 37 years old when she suffered a subarachnoid hemorrhage from spontaneous basilar artery dissection. At the time of the hemorrhage, minimal aneurysmal enlargement was noted angiographically, and she was therefore treated nonoperatively. On reimaging 5 months later, massive enlargement of the aneurysm was noted. The patient was treated with staged bilateral vertebral artery sacrifice using a combination of microsurgical and neuroendovascular techniques. The dominant vertebral artery was clip-ligated distal to the posteroinferior cerebellar artery, whereas the contralateral vertebral artery was coil-occluded cervically 1 week later. Conclusions: Despite the patient remaining asymptomatic, follow-up angiography 5 years after the initial hemorrhage revealed further enlargement of the aneurysm as well as a newly discovered inferiorly projecting daughter sac measuring 5 mm in diameter. Clearly, certain aneurysms exist for which indirect approaches involving hemodynamic attenuation fail to prevent progression. With greater refinements in stent technology, such lesions may be more effectively treated.