[Individualized imaging analysis of anatomic landmarks of parapharyngeal internal carotid artery via maxillary sinus approach].

Objective:To investigate the morphology of bone markers around the parapharyngeal internal carotid artery and its adjacent relationship. Methods:The imaging date of 30 cases which had normal structure of the skull by CTA were randomly selected. Through maxillary sinus approach, the morphology of peripheral bony landmarks （sphenoid spine, vaginal process of the tympanic bone, tympanic crest） from the parapharyngeal internal carotid artery to the entrance of the internal carotid artery and the adjacent relationship with the parapharyngeal internal carotid artery were observed for imaging anatomy. Results:With the external opening of the internal carotid artery as the reference point, the parapharyngeal internal carotid artery was divided into 10 sides （16.7%） in the direction of atlas and 6 sides（10%） in the direction of temporomandibular joint, 44 sides （73.3%） were close to midline. On 53 sides （88.3%）, the morphology of sphenoid spine became triangular shape with upper width and lower width, 6 sides （10%） became irregular type with terminal bifurcation, and 1 side （1.7%） had sphenoid spine missing. The shape of the vaginal process of the tympanic bone （VPTB） was a flat, irregular polygon with a smooth surface and no loss on 60 sides （100%）. The tympanic crest （TC） was a continuation of the VPTB to the sphenoid spine. It was located between the sphenoid spine and the VPTB. 51 sides （85%） of the TC and 9 sides （15%） of the TC were missing. The three constituted a special anatomical structure located in front of the internal carotid artery of the parapharyngeal segment, which can be divided into 43 inverted J-types （71.7%） and 17 irregular types （28.3%）. Conclusion:The special anatomical area composed of sphenoid spine, vaginal process of the tympanic bone, tympanic crest is closely related to the parapharyngeal internal carotid artery observed by maxillary sinus approach, which is the anatomical basis for endoscopic surgery to find the parapharyngeal internal carotid artery. CTA can provide individualized surgical basis.