Radiologic exploration of the morphometric and morphological features of the carotid canal

Objectives: The carotid canal is a foramen located in the petrous part of the temporal bone. Detailed knowledge about the anatomy of the base of the skull is important, as many surgeries are done there for various malignancies and aneurysms. The aim of this study was to collect various morphometric measurements of the carotid canal to aid neurosurgeons with various surgical approaches to easily locate the second fragment of the internal carotid artery. Methods: A retrospective study was done, and 500 CT scans on both sides of the skull were analysed. Various morphometric parameters related to the carotid canal were measured. The shape of the carotid canal was also noted. Statistical analysis was done for all the parameters. Results: The mean anteroposterior diameter and width of the carotid canal was 0.535 and 0.683 cm, respectively. The mean distance of the carotid canal from the external acoustic meatus, zygomatic arch, and mandible was 2.27, 3.28, and 2.34 cm, respectively. The mean distance of the carotid canal from the midline of the base of the skull was 2.97 cm. The mean angle between the zygoma root, external aperture of the carotid canal, and external acoustic meatus was 27.08°. The mean angle between the external acoustic meatus, external aperture of the carotid canal, and supramastoid crest was 26.74°. The carotid canal was round in most cases (50.5%). Conclusion: These measurements will aid neurosurgeons to identify various surgical approaches to easily locate the second part of the internal carotid artery, and they can serve as a reference to guide surgeries at the base of the skull.