Determination of the Pterional Approach Side According to the Direction of the Aneurysm and the Configuration of the H-complex in Anterior Communicating Artery Aneurysms

Kim, Ho Jae; Lee, Woo Chang; Min, Kyung Soo; Lee, Mou Seop; Kim, Young Gyu; Kim, Dong Ho

Abstract

OBJECTIVE
We proposed to study factors influencing the determination of operative side for easier and more successful clipping in the pterional approach to anterior communicating artery aneurysms and to determine the highest priority of factors in relation to the direction of the aneurysm. METHODS: The present study was conducted retrospectively in 91 patients with anterior communicating artery aneurysm who were operated on between January 1996 and December 2002. A1 dominancy, the size and the direction of aneurysms, the configuration of the H-complex especially the relative locations of both A2 segments in the coronal plane and the presence or absence of accompanying aneurysms were determined by angiogram. The degree of operative difficulty and factors influencing difficulty were reviewed with operative records and videos. RESULTS: In antero-inferior projecting aneurysms, when approached from the side of A1 dominancy, safe and easy clipping resulted(45/46cases). In superior projecting aneurysms, approaches from the side of the ipsilateral proximal A2 posterior to the contralateral A2 yielded favorable results(25/25cases), although the side was A1 non-dominant side. In some cases with posterior projecting aneurysms, approaches from the side of the posteriorly located A2 segment were inappropriate. CONCLUSION: In anterior communicating artery aneurysmal surgery, the A1 dominant side for antero-inferior projecting aneurysms and the side of the ipsilateral proximal A2 posterior to the contralateral A2 for superior projecting aneurysms should be considered prior to other factors. In posterior projecting aneurysms, angiographic analysis for the side where operator can observe the aneurysmal neck directly is required.