The influence of embolization of internal carotid artery aneurysms on arterial tortuosity: a prospective cohort study.

PURPOSE: To compare quantitative tortuosity descriptors of Internal Carotid Artery (ICA) on aneurysmal and non-aneurysmal side before and after embolization of aneurysm and to determine possible factors associated with its change.

MATERIAL AND METHODS: An analysis of 52 patients with intracranial aneurysm, treated with endovascular procedure, was performed. Based on their Digital Subtraction Angiography images, obtained prior to the procedure and after first follow-up examination, tortuosity of ICA, both on the side of embolization and on the other side was analysed. For each patient tortuosity descriptors were calculated: Relative Length, Sum of Angle Metrics, Triangular Index, Product of Angle Distance, and Inflection Count Metric. To represent changes in tortuosity, for each descriptor delta value (Δ) was defined as value of the descriptor prior to embolization - value of the descriptor on follow-up examination.

RESULTS: In the follow-up We found no statistically significant changes in tortuosity on non-embolized side. On the embolized side SOAM (2.89±0.92 vs. 2.38±0.94;p<0.001), PAD (5.01±1.83 vs. 3.95±1.72 ;p<0.001) and ICM (12.18±4.55 vs. 9.76±4.04 vs.;p = 0.006) was significantly higher after embolization than before embolization. Mean ΔRelative Length (-0.02 [-0.045--0.002] vs. -0.01 [-0.02-0.003];p - 0.003),ΔProduct of Angle Distance (0.84 [0.30 - 1.82] vs. 0.10 [-0.001 - 1.10];p<0.001) and ΔInflection Count Metric (2.05 [0.42 - 3.50] vs. 0.27 [0.02 - 2.16];p = 0.004) were significantly higher on the embolized side.

CONCLUSION: Following study showed that embolization may increase the tortuosity of ICA.