=====Petroclival region=====
The petroclival region is a small [[cistern]]al space located in the most anterior part of the [[posterior cranial fossa]].

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]]
((Grossi PM, Nonaka Y, Watanabe K, Fukushima T. The history of the combined supra- and infratentorial approach to the petroclival region. Neurosurg Focus. 2012 Aug;33(2):E8. doi: 10.3171/2012.6.FOCUS12141. PubMed PMID: 22853839.)).

see [[Sphenopetroclival region]]

see [[Petroclival tumor]]