Landmark thrombectomy trials demonstrated improved functional outcomes after endovascular therapy (EVT) for large core strokes (LCSs). This study explored the impact of recanalization attempts and procedure time (PT) on outcomes in LCS patients.

This was a retrospective study of patients with LCSs who underwent EVT from a prospective multicentre cohort. LCS was defined as an Alberta Stroke Program Early Computed Tomography Score of 0 to 5. Patients were divided into 6 groups (unsuccessful reperfusion [modified Thrombolysis in Cerebral Infarction Scale (mTICI) 0-2a] and successful reperfusion [mTICI, 2b/3]) after 1, 2, 3, 4, or >4 attempts. The primary outcome was a favorable 90-day mRS score of 0–3. Secondary outcomes included mRS 0–4, 90-day mortality, and 48-hour rates of symptomatic (sICH) and any intracranial hemorrhage (aICH).

A total of 447 patients were analysed. 388 with successful reperfusion, 59 without.Successful reperfusion during the first 3 passes increased the odds of favourable functional outcomes [attempt 1: aOR, 4.454 (1.723-11.514),p=0.002; 2: aOR, 3.762 (1.437-9.847),p=0.07; or 3: aOR, 3.619 (1.254-10.440),p=0.017] and decreased mortality at 90 days [(attempt 1: aOR, 0.336 (0.155-0.727),p=0.006; 2: aOR, 0.346 (0.160-0.746),p=0.007; or 3: aOR, 0.395 (0.164-0.953),p=0.039]. A shorter PT increased the odds of a favourable functional outcome [aOR, 0.991 (0.985-0.997),p=0.002]. PT may reduce the association between the number of attempts and patient outcomes. No associations were found between the number of attempts and sICH or aICH, whereas there was an increasing trend in the proportion of aICH or sICH when the number of attempts was more than two.

In patients with LCSs who underwent EVT, successful reperfusion within the first 3 attempts and a shorter PT were associated with favourable functional outcomes. However, the effect size of the association between the number of attempts and clinical outcomes may gradually decrease with extension of the PT.