Comprehensive assessment of internal carotid artery tortuosity combined with stenosis regarding the indications for surgical treatment

Objective. To evaluate diagnostic significance of tortuosity index (TI) and blood flow velocity gradient (BVG) in comprehensive assessment of patients with internal carotid artery (ICA) tortuosity with minor atherosclerotic stenosis and critical stenosis of ICA regarding the indications for surgical treatment. Material and methods. A retrospective single-center study included 135 patients with unilateral ICA tortuosity divided into 2 groups: 55 patients with ICA tortuosity and stenosis<50% (NASCET), 80 patients with ICA tortuosity and stenosis >70%. Mean age was 63.5±10.3 years. All patients underwent CT angiography of extracranial arteries and Doppler ultrasound. TI, BVG and deformation type (C-type, S-type, coiling, and kinking) were assessed. TI ≥1.2 and/or BVG >2.5 determined hemodynamically significant tortuosity. These parameters were compared between groups using descriptive statistics, correlation and ROC analysis. Results. Both groups were comparable in age and gender. Smoking (OR=4.6; p<0.001) and arterial hypertension (OR=1.5; p=0.035) were significant risk factors for stenosis. S-deformity prevailed among patients without stenosis (58% vs 24%; p<0.001), while coiling was more common in another group (22% vs 4%; p=0.002). TI and BVG correlated with severity of stenosis (r=0.342 and r=0.706; p<0.001). Coiling was associated with the highest TI (p<0.001), while kinking was associated with high BVG (p<0.001). ROC analysis demonstrated high diagnostic value of TI for coiling (AUC=0.939) and BVG for kinking (AUC=0.714). BVG was a key predictor of stenosis (OR=19.1; p<0.001), while TI was a key predictor of stroke (OR=8.65; p=0.003). Surgical treatment reduced the risk of stroke (plog-rank=0.04). Conclusion. A comprehensive assessment of patients with ICA tortuosity using TI and BVG together with CT angiography and Doppler ultrasound data allows for a more accurate diagnosis and informed decision-making regarding the need for surgical intervention.