Mohamed Amad Jamaluddin2021-03-122021-03-122019-12https://dspace.sctimst.ac.in/handle/123456789/11039The anterior petrous apex has been considered as a gateway to the posterior cranial fossa. The anterior petrosectomy as described by Kawase converts this deep narrow operative corridors into wider shallower exposures, improves manoeuvrability and minimizes retraction. It comprises of a sub-temporal craniotomy followed by extradural drilling of the petrous apex to reach the posterior fossa. The traditional Kawase approach provides a 10×5 mm fenestration at the petrous apex of the temporal bone between the 5th cranial nerve and internal auditory canal and the greater superficial petrosal nerve. Complications of this approach include palsies of facial, trigeminal and abducent nerve, CSF leak, hearing loss, injury to the vein of Labbe, etc. This study aims to calculate the amount of bone resected in an anterior petrosectomy done in this institute and with this knowledge, quantify the differential variations used in each surgery while achieving adequate exposure with respect to the local complications will provide a better understanding of this approach. The study ought to define minimal safe resection for a lesion with the best local outcome while preserving the adequacy of exposureenThesis