The anatomical relationship between the eustachian tube and petrous internal carotid artery.

OBJECTIVES/HYPOTHESIS: The aim of the present study was to investigate the relationship between the eustachian tube (ET) and petrous internal carotid artery (ICA) in whole-mount human temporal bone specimens.

STUDY DESIGN: Descriptive study.

METHODS: Histologically prepared serial sections of 10 adult temporal bones were included in the study. Five specific landmarks were selected to evaluate relationships between the petrous segment of the ICA and the ET. The selected distances were measured using computer software (Metamorph 7.5.2.0; Molecular Devices, LLC, Sunnyvale, CA).

RESULTS: The ET and the ICA get close posteriorly, and the bony part of the ET and the ICA generally share the same wall.

CONCLUSIONS: The junctional part of the ET may be a safe landmark to identify and protect the ICA during endoscopic endonasal surgery of the cranial base. Knowledge of the anatomical relationships of the ET and petrous part of the ICA, as well as their relationship with other surgical and radiological landmarks, would be useful to surgeons.