Is Thrombectomy Effective for Large Vessel Occlusion Stroke Patients with Mild Symptoms? Meta-Analysis and Trial Sequential Analysis

Abstract

Background: Endovascular treatment (EVT) is an established method for managing large vessel occlusion (LVO), but its efficacy in patients with mild stroke (National Institutes of Health Stroke Scale [NIHSS] score < 6) remains debated. Given the clinical problem of early neurological deterioration in approximately 10% of mild stroke patients, understanding the role of EVT in managing these patients is crucial. Our objective was to perform a meta-analysis with trial sequential analysis (TSA) focusing on mild stroke patients with LVO to determine whether EVT offers better outcomes than best medical therapy alone. Methods: A comprehensive search of PubMed, Cochrane, and Embase databases up to 12 December 2023 identified 14 retrospective and prospective cohort studies, including a total of 4436 patients with NIHSS scores less than 6 and presenting with LVO. Studies were categorized into crossover and non-crossover groups to prevent overestimation of the treatment effect. In the crossover group, patients initially treated with BMT were moved to EVT upon clinical deterioration. In the non-crossover group, patients remained in their initially assigned treatment. Meta-analysis and data extraction followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome was achieving an excellent functional outcome, defined as a modified Rankin scale (mRS) score of 0–1 at 3 months. Secondary outcomes included good (mRS 0–2) and favorable (mRS 0–3) functional outcomes. Safety outcomes were symptomatic intracerebral hemorrhage (sICH) and mortality at 3 months. Results: In the crossover group, EVT did not significantly improve excellent functional outcomes, and TSA results were inconclusive. Conversely, in the non-crossover group, EVT significantly improved the excellent functional outcome rates at 3 months (65.0% vs. 53.7%; OR 1.62; 95% CI 1.13 to 2.32), supported by TSA. EVT increased the risk of sICH in both crossover and non-crossover groups, while mortality rates did not significantly differ between EVT and BMT groups. Conclusions: Our research indicates that thrombectomy may not significantly help mild stroke patients in recovering functional status and could increase the risk of sICH. The disparity in results between crossover and non-crossover studies highlights the critical need for the prompt identification of patients at risk of early neurological deterioration to minimize negative outcomes. Additional randomized controlled trials are essential to optimize the application of EVT in this patient population.

Keywords

• acute ischemic stroke
• endovascular thrombectomy
• large vessel occlusion
• low NIHSS score
• meta-analysis