Abstract
The pterional approach was described in 1975 by Yaşargil and became thereafter the gold standard for the treatment of anterior circulation aneurysms [11]. During the last decade, minimally invasive surgical approaches such as the lateral supraorbital [1, 9] and the mini-pterional [5] have been reported [1, 10]. Aim of this chapter is to describe and illustrate the most common craniotomies nowadays used for clipping aneurysms of the anterior circulation: pterional (PT), lateral supraorbital (LS), mini-pterional (MP) and parasagittal (PS) approaches.