機械的血栓回収における放射線線量低減：シングル対デュアルオペレーターアプローチ

Objective: The number of operators performing mechanical thrombectomy (MT) may influence procedural outcomes; however, evidence remains limited and conflicting. This study aimed to comprehensively evaluate the impact of single versus dual operators on procedure time, radiation dose, and angiographic success in patients undergoing MT for acute ischemic stroke. Methods: In this single-center, retrospective cohort study, 285 consecutive patients who underwent MT for large-vessel occlusion between January 2020 and December 2024 were included. Patients were grouped according to institutional workflow: single-operator procedures (n = 157) and dual-operator procedures (n = 128). The primary endpoints were procedure time and radiation dose parameters, including total Kerma-Area Product (PKA). Secondary endpoints included successful reperfusion (TICI ≥ 2b), complete reperfusion (TICI 3), and first-pass success (FPS, defined as TICI 2c/3 with a single pass). Results: Baseline characteristics were comparable between groups. The dual-operator group had significantly shorter median procedure times (52.5 vs. 85.0 min, p < 0.001) and lower total PKA (p < 0.001). Reperfusion rates were significantly higher in the dual-operator group, both for successful reperfusion (TICI ≥ 2b: 80.5% vs. 64.3%, p = 0.004) and complete reperfusion (TICI 3: 76.6% vs. 58.5%, p = 0.002). First-pass success was also more frequent (60.0% vs. 44.5%, p = 0.0146), and the mean number of passes was lower (1.66 vs. 2.00, p = 0.0057). Conclusions: Mechanical thrombectomy performed with two experienced operators was associated with greater procedural efficiency, reduced patient radiation exposure, and higher angiographic success compared with single-operator procedures. These findings support considering the dual-operator model as an approach that may inform workforce planning and workflow decisions in stroke centers.