Occlusion Type, Number of Recanalization Passages and Dose Program Determine Radiation Dose in Endovascular Stroke Thrombectomy.

Purpose: Identification of independent treatment factors associated with high radiation exposure during endovascular mechanical thrombectomy (EMT) in acute ischemic stroke.

Methods: This retrospective analysis included all patients treated by means of EMT during the 2‑year period 2017-2018 in a comprehensive stroke center. The EMT were performed by four internal and three external certified neuroradiologists in a clinic overlapping on call system. Radiation exposure as the dependent variable (dose area product DAP, Gy ⋅ cm) was dichotomized in < 100 Gy ⋅ cm and ≥ 100 Gy ⋅ cm. Independent variables were age (< 75 years vs. ≥ 75 years), time of intervention (during vs. beyond workday), treating neuroradiologist (internal vs. external), occlusion type ("mono" vs. "tandem"), reperfusion success (TICI 0-2A vs. TICI 2B/3), recanalization attempts (≤ 2 vs. > 2) and dose protocol (normal dose in 2017 vs. low dose in 2018).

Results: The EMT treatment of 208 patients (111 female, 97 male, mean age 71.6 years) was analyzed. Median DAP was 86.6 Gy ⋅ cm and could be reduced from 104.8 Gy ⋅ cm (N = 105 in 2017) to 73.3 Gy ⋅ cm (N = 103 in 2018) with LD program. Univariable and multivariable binary logistic regression analysis revealed a significantly increased radiation exposure (≥ 100 Gy ⋅ cm) in tandem occlusion type (P < 0.001), > 2 recanalization attempts (P < 0.001) and normal dose protocol (P = 0.002).

Conclusion: Low dose programs can significantly reduce the radiation exposure in EMT. High radiation exposure is significantly associated with more than two recanalization attempts and in cases of tandem occlusions.