de Sousa described his experience with 123 operated patients of basilar bifurcation aneurysms from January 1977 till December 1995. In these 123 consecutive surgeries the results were 85% good outcome, 8.1% morbidity, and 6.5% mortality. In the first years of this series the [[pterional]] or [[subtemporal approach]]es were used, depending on the level of the basilar bifurcation, the exact origin of the sac, its projection and size. From 1987 on all patients were operated by a modified pterional approach described initially by Sano as [[temporopolar approach]]
((de Sousa AA. Basilar bifurcation aneurysms. Neurol Med Chir (Tokyo). 1998;38
Suppl:70-3. PubMed PMID: 10234981.
)).