Anterior Petrosal Approach

The anterior petrosal approach (APA) is one of the pillars of skull base surgery and one of the most challenging approaches. It offers indirect access to the posterior fossa through the temporal fossa floor and under the temporal lobe. It is therefore a looking-down approach. Initially described by ENT, it was popularized in the neurosurgery community as the “Kawase approach.” Once the dura is elevated, several landmarks, along the temporal fossa floors, help the surgeon delineate the volume of bone to be drilled to expose the posterior fossa dura while preserving critical neurovascular structures. These key landmarks are variable in shape and location and should be carefully evaluated preoperatively. The numerous potential complications require adequate surgical skills and a perfect knowledge of the key surgical steps. In this manuscript, the surgical anatomy, relevant anatomical variations, key surgical landmarks and steps, complications, and tips and tricks to avoid them, as well as indication for use, are presented.