The partial labyrinthectomy petrous apicectomy approach to petroclival meningiomas. A quantitative anatomic comparison with other approaches to the same region.

The partial labyrinthectomy petrous apicectomy (PLPA) approach is a transpetrous route that provides the advantages of the labyrinthine removal but with hearing preservation. Using seven temporal bone tissue blocks and three formaldehyde-fixed cadaveric heads we have made a morphometric and comparative study on this approach that summarizes the invasiveness, the optimal surgical exposure, the anatomic complexity of the skull base approaches and, on the other hand, the spirit of preservation that is the constant aim of modern neurosurgery. The morphometric analysis is designed to make the bony phase of the PLPA approach safer and to define the relationship between petrous landmarks. The comparative study is made between the PLPA and other neurosurgical routes enhancing the potentiality of the PLPA approach that permits a wider angle of incidence towards the brainstem than with the retrosigmoid routes.