Surgical Approaches to Basilar Tip Aneurysms

Rha, Hyung Kyun; Lee, Kyung Jin; Park, Hae Kwan; Park, Sung Chan; Cho, Kyung Keun; Lee, Sang Won; Baek, Min Woo; Kim, Dal Soo; Kang, Joon Ki; Choi, Chang Rak

Abstract

In an attempt to decide the surgical approach to basilar tip aneurysms, 27 cases of ruptured aneurysms were retrospectively analysed for size of aneurysm, direction of fundus and height of bifurcation. The fundus pointed superiorly in 18 cases, posteriorly in six, and anteriorly in three. The aneurysm neck was positioned as follows : very high(more than 20mm above midsellar) in one case, high(between 10mm and 20mm above midsellar) in 13, mid(from midsellar to 10mm above it) in nine, low(from midsellar to sellar floor) in two, and very low(below the sellar floor) in two. In 11 cases, surgery followed the conventional pterional approach ; in eight, the orbitozygomatic ; in three, the pterional-anterior temporal ; in two, the subtemporal ; in two, the anterior transpetrosal ; and in one, the temporopolar. In complex aneurysms or basilar bifurcation was at an unusual height, surgery involved a skull-base or modified technique based on a conventional pterional and subtemporal approach. On the basic of our surgical data and related findings, our suggestious are as follows : surgery involving basilar tip aneurysms with an extremely high-positioned neck should follow the transsylvian route above the carotid bifurcation, or use a transventricular or intravascular approach ; in cases with a high positioned-neck, the orbitozygomatic temporopolar or transzygomatic subtemporal approach should be used ; in cases with a normal-positioned neck, the combined pterional-anterior temporal approach, which has a much wider operative field and wider angle of vision than the classic pterional and subtemporal approach ; in cases with a low-positioned neck, the subtemporaltranstentorial) pterional, with resection of the posterior clinoid process ; and in cases with a very low-positioned neck, the transpetrosal approach.