Introduction: Aneurysm configuration is known to correlate with outcome and success of treatment modality. The aim of this retrospective analysis is to evaluate the effect of an aneurysm's configuration on initial occlusion rates and recurrence rates after coil embolization.

Method: This study enrolled 203 patients with 214 aneurysms who underwent detachable microcoil embolization between August 2002 and September 2008. Aneurysm configuration was determined by the authors' review of the initial angiograms. The configurations were classified as follows: regular spherical (RS) when the aneurysm had one spherical lobe with or without small blisters; regular long (RL) when …