Endoscopic access to the inferior petrous apex. Opening clival dura provides access to the ventrolateral aspect of the brainstem. The abducens nerve arises from the pontomedullary junction. The facial and vestibulocochlear nerves can be seen travelling toward the internal acoustic canal (IAC). The anterior-inferior cerebellar artery (AICA) arises from the basilar artery and makes a loop into the IAC. The lower cranial nerves can be seen running to the jugular foramen. Note in the top of the image the proximal root of the trigeminal nerve. (Image courtesy of JC Fernandez-Miranda)