GDC Embolization of Basilar Bifurcation Aneuryms; Consideration of Posterior Cerebral Artery Occlusion

ABSTRACT

OBJECTIVE: To access the risk factors of posterior cerebral artery(PCA) occlusion during endovascular treat-ment of basilar bifurcation aneurysm and importance of collateral circulation through posterior communicating artery(PCoA) after PCA occlusion, the authors review the results of 25 patients with basilar bifurcation aneurysms treated with Guglielmi detachable coils(GDCs). METHODS: Male to female ratio was 1: 3.2(6: 19) and the mean age of this group was 54. Nineteen patients were presented with subarachnoid hemorrhage, 1 patient had neurologic deficits of hemiplegia and dysarthria, and 5 patients had incidental aneurysms with headache and dizziness. All patients underwent GDC embolization and their clinical results were analyzed. RESULTS: Seven of nine patients who resulted in PCA occlusion had a collateral flow from the anterior circulation through PCoA. Six patients had a PCoA larger than 1mm and they had no symptoms of ischemia after PCA occlusion. One patient who had a PCoA with 0.53mm in diameter had transient ischemic symptoms. The PCA arouse from the aneurysm neck in seven patients, and six of them resulted in PCA occlusion. Four of five patients who had aneurysms with broad neck(<4mm) resulted in PCA occlusion. CONCLUSION: The aneurysm with either broad neck or PCA arising from the aneurysm neck have a high risk of PCA occlusion. After PCA occlusion, significant blood flow from anterior circulation through the PCoA larger than 1mm in diameter can minimize the ischemic result in PCA territories.