Impact of Successful Recanalization and Clinical Outcomes of Patients With Acute Ischemic Stroke with 5 or More Thrombectomy Passes

BACKGROUND: As the number of thrombectomy passes increases during endovascular therapy (EVT) for acute stroke, neurointerventionalists must weigh the risks of potential complications against the risk of failing to recanalize the affected vessel. Thus, we investigated the effectiveness and safety of EVT for patients with acute stroke in which >= 5 EVT passes were performed. METHODS: This retrospective cohort study from January 2013 to December 2022 included 31 thrombectomy-capable centers. Patients in whom >= 5 EVT passes were made were included in the analysis. The patients with successful recanalization defined as modified Thrombolysis in Cerebral Infarction >= 2b at 5, 6, 7, or more passes were compared with unsuccessful recanalization. We also compared procedure time, separated by 30 minutes. Primary outcome was a favorable 90-day outcome (modified Rankin scale score of 0-2). Secondary outcomes were intracranial hemorrhage and death. RESULTS: A total of 407 patients met the inclusion criteria, of which 175 were women (43.1%); the mean age was 67.3 years. In 265 (65.1%) patients, successful recanalization was achieved: 134 patients with 5 passes, 67 patients with 6 passes, and 64 with >= 7 passes. Intravenous recombinant tissue plasminogen activator administration was more common in the unsuccessful recanalization group (successful recanalization with 5, 6, and >= 7 EVT passes and unsuccessful recanalization: 35.3%, 30.3%, 18.8%, and 45.4%, respectively). Successful recanalization with 5, 6, and >= 7 EVT passes was associated with favorable outcome compared with unsuccessful recanalization group (adjusted odds ratio successful recanalization with 5, 6, and >= 7 EVT passes to unsuccessful recanalization [95% CIs]: 8.29 [2.13-32.3]; 14.0 [3.27-60.3]; and 5.26 [1.12-24.8], respectively). However, symptomatic intracranial hemorrhage was not significantly different between the groups. Regarding procedure time, favorable outcome was not significantly different in each group, while symptomatic intracranial hemorrhage occurred more frequently in the 60 to 89 minutes group compared with the <30 minutes group (adjusted odds ratio, 60-89 minutes group to <30 minutes group [95% CI]: 5.86 [1.09-31.6]). CONCLUSION: These findings suggest that a benefit in outcome persists for recanalization, without significant increase in complications. In addition, there was no significant difference in favorable outcomes among procedure time.