Preprocedural Curvature Assessment Can Stratify Recanalization Risk Before Device Selection in Mechanical Thrombectomy

Vascular geometry may impede catheter navigation during mechanical thrombectomy. We evaluated whether cervical curvature predicts recanalization success.

This is a retrospective single-center cohort of 160 anterior large vessel occlusion patients treated with mechanical thrombectomy at a comprehensive stroke center (Barnes-Jewish Hospital/Washington University School of Medicine, St. Louis, MO) from May 2019 to February 2021. Cervical curvature was computed using 3-dimensional vessel centerlines derived from preprocedural computed tomography angiography. Primary outcomes were successful recanalization (final modified Thrombolysis in Cerebral Infarction score ≥2b) and intracranial access time (puncture→first pass). Associations were evaluated with multivariable linear or logistic regression, adjusting for age, National Institutes of Health Stroke Scale, first-line device, and access route. Random Forest and Gradient Boosting models with Gini Importance and Shapley Additive Explanation explained feature importance.

Mean age was 67±15 years; median National Institutes of Health Stroke Scale 16; mean total curvature was 9.80±2.85. Median intracranial access time was 24 minutes (interquartile range, 17-32), with no correlation to cervical curvature (ρ=0.054; adjusted β=0.20 min/unit [95% CI, -0.75, 1.15]; P=0.676). Successful recanalization occurred in 86% and varied across curvature tertiles (low 91%, mid 93%, high 75%; P=0.017). Per-unit curvature increase was associated with recanalization failure (adjusted odds ratio, 1.21 [95% CI, 1.02-1.43]; P=0.028). Receiver operating characteristic-derived curvature threshold (>11.54) identified a high-risk group (adjusted odds ratio, 5.10 [95% CI, 1.88-13.84]; P=0.001). Machine learning confirmed cervical curvature as the dominant predictor, with a Shapley Additive Explanation peak effect at 11.65.

Cervical curvature independently predicts mechanical thrombectomy recanalization failure, with a threshold effect near 11.6 units. Preprocedural curvature assessment derived from routine computed tomography angiography may improve risk stratification and inform mechanical thrombectomy strategy.