The Efficacy and Safety of Intra-Arterial Thrombolysis in Mechanical Thrombectomy: A Systematic Review and Meta-Analysis

Introduction: Intra-arterial thrombolysis (IAT) after mechanical thrombectomy (MT) may improve microvascular reperfusion and reduce disability in patients with ischemic stroke. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational cohort studies to investigate the efficacy and safety of MT combined with IAT for the treatment of acute ischemic stroke. Methods: We searched PubMed, Embase, Cochrane Library, and Web of Science databases in all languages published from inception to May 30, 2025, using the search terms “stroke”, “thrombectomy”, “intra-arterial thrombolysis”. The primary efficacy outcome was excellent functional outcome (modified Rankin scale 0–1) at 90 days and the key safety outcomes were death and symptomatic intracerebral hemorrhage. Effect sizes were computed as risk ratio (RR) with random-effect or fixed-effect models. Results: Seven RCTs and 9 cohort studies with a total of 6,258 patients met the inclusion criteria. The results of the RCTs indicated that for patients with large vessel occlusion stroke who were treated with MT and achieved successful recanalization, the subsequent administration of IAT significantly increased the chances of excellent functional outcome (mRS 0–1, RR: 1.24, 95% CI: 1.12–1.37, p < 0.0001) without increasing the risk of sICH or death. While cohort studies lacked excellent functional outcome rates, other endpoints were consistent with RCTs. The results of subgroup analysis suggested that, in patients who did not receive IVT before MT, the combination of MT and IAT significantly improved the likelihood of achieving excellent functional outcomes (RR: 1.17, 95% CI: 1.04–1.32). Conclusion: This systematic review and meta-analysis indicated that MT combined with IAT could lead to a higher opportunity of excellent functional outcome (mRS 0–1) than MT alone in acute stroke. Importantly, adding IAT was safe and did not increase the risk of symptomatic intracranial hemorrhage and death.