Software-enabled computed tomography analysis of the carotid artery and sphenoid sinus pneumatization patterns

Background: The critical relationship of the carotid artery with the sphenoid sinus has been long established. Sophisticated imaging software in conjunction with three-dimensional high-resolution computed tomography (CT) imaging now facilitates detailed analysis of these anatomic relationships. Methods: Siemens VolumeZoom CT scanner was used to obtain high-resolution computed tomography data that was subsequently transferred to the CBYON Suite Doctor Station version 2.6 for analysis. Various surgical planning tools were used for evaluating the CT scans. The relationship of the carotid artery with the sphenoid sinus was delineated. Results: One-hundred twenty-eight sides in 64 cadaveric specimens were reviewed. Pneumatization of the sphenoid sinus was classified into four categories: conchal, presellar, sellar, and postsellar. The incidence of these four types was 4.7, 4.7, 25, and 65%, respectively. Carotid artery exposure was categorized as follows: no exposure, <90degrees, >90 to <180degrees, and <180degrees. The incidence of the carotid exposure was 12.5, 32.8, 50, and 4.7%, respectively. Septal insertions onto the carotid artery were noted in 37.5% and dehiscences in 19.5% of the specimens. Conclusion: Computer-aided CT analysis allows for a detailed study of the critical relationship of sphenoid pneumatization and carotid artery position. Such technology can be invaluable in surgical planning and navigation during endoscopic sinus surgery. In lieu of these findings, sinus surgeons must exercise extreme caution when operating in this region to prevent unintentional injury to the carotid artery.