Introduction: The shape and position of the cavernous segment of the internal carotid artery (CSICA) are complicated, which makes the surgeries around it difficult. There were many reports about the primary event of internal carotid artery injury resulting in hemorrhage during transsphenoidal resection of pituitary tumors. The anatomical relationship between CSICA and the structures in the sella region around can explain its mechanism.
Purpose: We study the CSICA and its positional relationship to some stationary structures in the sellar region to locate CSICA and prevent it from injuring in the process of transsphenoidal surgery.
Material and methods: Computed topographic angiography images of 144 internal carotid arteries in individuals were reviewed. The distance from CSICA to midpoint of sella bottom (SB) and the angle between line BA and line BM were measured in the coronal plane, which is across the middle point of SB. The vertical distance from the anterior curve segment of CSICA to the top edge of the sphenoid sinus was measured in people with sphenoid sinus of types III and IV. The horizontal distance between the midpoint of the posterior curve segment and the coronal middle line of SB was measured in the sagittal plane after multiplanar reformation.
Results: The mean (SD) distances from the CSICA to the midpoint of SB were 11.25 (3.35) mm in the right and 11.06 (2.98) mm in the left, and the mean (SD) angles between line BA and line BM were 74.2 (2.16) degrees in the right and 73.5 (2.33) degrees in the left. The mean (SD) vertical distance between the anterior curve segment of the CSICA and the top edge of the sphenoid sinus was -0.62 (0.96) mm, the mean (SD) of the right side was -0.68 (1.24) mm, and the mean (SD) of the left was -0.54 (1.15) mm. The mean (SD) horizontal distance between the midpoint of PS segment and the coronal middle line of SB was 6.41 (1.94) mm in the right and 6.31 (1.33) mm in the left.
Conclusions: The data in our study are valuable for surgeons in real clinical practice to achieve the best possible surgical outcome and maximize safety, and they also contribute to the understanding of the anatomy of CSICA and the structures around.