The effect of cavernous internal carotid artery tortuosity on mechanical thrombectomy outcomes: analysis of a single center 5-year cohort and validation of prior scales.

Abstract

Introduction: Tortuosity of the cavernous internal carotid artery (cICA) complicates neuro-endovascular access. Improved assessment of cICA tortuosity could improve procedural outcomes. This study attempts to refine cICA tortuosity classification through analysis of its effect on mechanical thrombectomy (MT) outcomes and to externally validate previously scales.

Methods: Retrospective single center review of 191 patients who underwent transfemoral anterior circulation MT over 5 years. Four parameters of cICA tortuosity were measured. Regression analysis was performed on cICA parameters influencing first pass revascularization success and time to revascularization. Significant cICA parameters were then divided into a 3-tier ordinal scale. Three existing cICA tortuosity scales (Lang-Reiter, Lin, and Chen) were similarly analyzed. All scales were compared using area under receiver operator characteristic curve (AUROC).

Results: None of the cICA parameters were associated with first pass success. Revascularization times were longer with higher true genu height (TGH) (p = 0.04) and lower posterior genu angle (PGA) (p = 0.04). TGH and PGA had a strong inverse correlation. In predicting revascularization time, the TGH and PGA scales found statistically significant differences when comparing mild versus severe classifications. The Lin, Chen, and TGH scales found statistically significant differences between their mild versus moderate classifications. AUROC for all scales ranged from 0.57 to 0.59 for first pass success with Chen, TGH, and PGA scales statistically superior to chance.

Conclusions: Two single metrics obtained on lateral angiography, TGH and PGA, performed as well as more complex scales for predicting MT outcomes. Further external validation of these metrics is warranted.