Endovascular Coil Embolization of Unusual Posterior Inferior Cerebellar Artery Aneurysms

Three patients underwent transarterial platinum coil embolization of unusual posterior inferior cerebellar artery aneurysms. In one case, a giant, bilobed, partially thrombosed aneurysm exhibited marked mass effect on the adjacent medulla. In the second case, diffuse severe cerebral vasospasm, 3 days after subarachnoid hemorrhage, rendered transvascular treatment of the aneurysm difficult. Increasing vertigo and nausea caused by mass effect from an aneurysm previously coated with methyl methacrylate warranted treatment in the third case. Indications for transvascular coil treatment included relative surgical inaccessibility to the aneurysm, and, in our case, inability to perform transarterial detachable balloon therapy. The aneurysms were obliterated by endovascular coil embolization in each case. In the patient with vasospasm, aneurysm treatment followed angioplasty of the major affected cerebral vessels, resulting in significant neurological improvement within 24 hours. Two patients were neurologically intact at the time of discharge, and the third displayed persistent cerebellar signs despite a marked decrease in vertigo and nausea. Reports of transvascular coil embolization of intracranial aneurysms are very rare. Our experience with these patients demonstrates that this technique can be successfully utilized in selected cases.