The Influence of Embolization of Internal Carotid Artery Aneurysms on Arterial Tortuosity: A Prospective Cohort Study.

ABSTRACT

PURPOSE: To measure changes in quantitative tortuosity descriptors of the internal carotid artery (ICA) after intracranial aneurysm embolization, and to determine possible factors associated with changes in tortuosity. MATERIALS AND METHODS: An analysis of 52 patients with embolized intracranial aneurysms was performed. ICA tortuosity was assessed by digital subtraction angiograms obtained prior to the embolization and after the first follow-up examination. For each patient, tortuosity descriptors were calculated relative length (RL), sum of angle metrics (SOAM), triangular index, product of angle distance (PAD), and inflection count metric (ICM). To represent changes in tortuosity for each descriptor, delta (Δ) value was defined as value of the descriptor prior to embolization minus value of the descriptor on follow-up examination. RESULTS: In a median follow-up of 14 months, no statistically significant changes in tortuosity were observed on the nonembolized side. On the embolized side, SOAM (2.89 [SD ± 0.92] vs 2.38 [SD ± 0.94]; P < .001), PAD (5.01 [SD ± 1.83] vs 3.95 [SD ± 1.72]; P < .001), and ICM (12.18 [SD ± 4.55] vs 9.76 [SD ± 4.04]; P = .006) were significantly higher after embolization than before embolization. Median ΔRL (-0.02 [-0.045 to 0.002] vs -0.01 [-0.02 to 0.003]; P = .003), ΔPAD (0.84 [0.30-1.82] vs 0.10 [-0.001 to 1.10]; P < .001), and ΔICM (2.05 [0.42-3.50] vs 0.27 [0.02-2.16]; P = .004) were significantly higher on the embolized side. Tortuosity correlated with elapsed time after embolization. CONCLUSIONS: Tortuosity of the ipsilateral ICA increased after intracranial aneurysm embolization.