The relationship of the basilar artery bifurcation and dorsum sel­lae

Abstract

Aims: The aim of the study was to assess the position of the terminal basilar artery bifurcation (BAB) in relation to the dorsum sellae (DS) based on computed tomography scans of the head. The BAB is in most cases formed by two P1 segments of the posterior cerebral arteries at the level of the interpeduncular fossa, in close proximity to the DS. This type of division is called bifurcation. Numerous pathologies may develop in this region, including BAB aneurysms, which account for 5–8% of all intracranial aneurysms. The literature states that the position of an aneurysm in relation to the DS plays a significant role in planning surgical strategies for BAB aneurysms. Materials and methodology: The study involved 100 computed tomography angiography (CT angiography) scans of 54 women and 46 men aged 18–88 years (mean age 52.49 years). Multiplanar reconstructions were used. The position of the BAB in relation to the sagittal midline plane (MP) and the lowest DS point (LDSP) in the transverse plane (TP) was analysed in the coronal section. The distance between the BAB and DS was measured in the sagittal section. Results: In the studied patients ( n = 100), the BAB was located on the right of the MP in 57% of cases, on the left of the MP in 41% of cases and in the midline or median position in 2% of cases. The BAB was located above the LDSP (TP) in 47% of cases, and below it in 53% of cases. There were no cases of the BAB located in the TP. The average distance between the BAB and MP was 0.35 mm, SD 1.91 mm, and the average distance between the BAB and the TP was 1.01 mm, SD 4.47 mm. Moreover, the average distance between the BAB and the DS was 9.34 mm, SD 2.61 mm. Conclusions: The study revealed no statistically significant differences in BAB position depending on gender. However, a highly significant difference and higher location of the BAB in relation to the TP (in relation to the DS) was observed in persons older than 45 years of age.