Endoscopic anatomy of the petrous segment of the internal carotid artery.

BACKGROUND: Exposure of the petrous (C2) segment of the internal carotid artery (ICA; petrous carotid) is necessary to treat lesions that have spread from the intracranial space or adjacent sinonasal region. Recent advancements in endonasal-endoscopic approaches to the anterior skull base raise the possibility of extending these approaches beyond the sinonasal cavity. In this cadaveric study, we evaluate the feasibility and extent of exposure of the petrous carotid artery via a combined endoscopic endonasal approach.

METHODS: Endoscopic dissection was performed in four formalin-fixed cadaver heads (eight sides). An endoscopic, endonasal, transmaxillary approach was used to identify the cervical and petrous carotid artery.

RESULTS: With the endoscopic endonasal, Caldwell-Luc approach, we could visualize the ventral petrous bone after dissecting the contents of the pterygopalatine fossa and infratemporal fossa. Careful dissection allowed exposure of the petrous carotid artery from the upper cervical carotid to the foramen lacerum.

CONCLUSION: In this cadaveric study using an endoscopic endonasal approach for exposure of the petrous carotid artery, combination with the transmaxillary-transpterygopalatine-transinfratemporal approaches permitted exposure of the ventral portion of the artery. The anatomy presented will assist experienced endoscopic skull base surgeons in the removal of lesions involving the ventral skull base.