It is defined by complex osteomeningeal edges but at the top, it opens onto the supratentorial sector, at the bottom onto the peribulbar area, and behind onto the area of the cerebellopontine angle.
Numerous surgical approaches have been developed to access the petroclival region. The Kawase approach, through the middle fossa, is a well-described option for addressing cranial base lesions of the petroclival region.
Early attempts to expose this region consisted primarily of an extended suboccipital craniectomy, with opening of the tentorium and ligation of the sigmoid sinus for additional exposure. During the 1960s, technological innovations including the surgical microscope and the pneumatic drill allowed surgeons to gain additional exposure by removing more bone from the skull base. This let surgeons define combined infra- and supratentorial approaches, which rely less on brain retraction to resect these difficult tumors successfully. These approaches rely on a combined posterior mastoid approach with an anterior petrosectomy 1).