Approaches to posterior circulation aneurysms and results of the operations.

Surgical approaches and operative results in 32 operations of aneurysms of the vertebrobasilar system are presented. The orbitozygomatic and temporopolar approach was used for aneurysms of the bifurcation of the basilar artery lying high in the interpeduncular fossa. In aneurysm which neck was located less than 10 mm above or less than 5 mm below the anterior and posterior clinoid processes the pterional transylvian subtemporal and pterional anterior temporal approaches were performed. A large aneurysm with the neck lying 5 mm below the line connecting the anterior and posterior clinoid processes was operated on via pterional transcavernous approach. The used approaches made it possible to clip the aneurysms. Good and very good results were obtained in 82 per cent of cases. The perioperative mortality was 9 per cent.