Severity-Based Triage for Direct Transportation to Nearest Comprehensive Stroke Center: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES: The efficacy of endovascular thrombectomy (EVT) for acute ischemic stroke due to large vessel occlusion (LVO) is time dependent. Patients initially transported to a primary stroke center (PSC) may require secondary transfer, potentially delaying EVT. For severely affected patients, bypassing the PSC for direct transport to a comprehensive stroke center may expedite EVT but risks delaying IV thrombolysis. Effects of prehospital bypass strategies on functional outcomes are thus uncertain. METHODS: For this systematic review and meta-analysis, PubMed and Web of Science were searched until December 2025. Randomized and nonrandomized studies comparing transport to the nearest stroke center with transport to a more distant comprehensive stroke center in patients with suspected stroke were included. Two investigators independently screened records, selected eligible studies, extracted summary data, and assessed risk of bias. Random-effects meta-analysis was used to quantify associations between prehospital bypass, endovascular therapy, and functional outcomes. RESULTS: Literature search identified 1,991 distinct reports. Of 18 eligible studies, 2 were randomized controlled trials (RCTs, n = 1,540 patients), 11 before-after studies (n = 11,837), and 5 cross-sectional studies (n = 1,139), comprising a total of 14,516 patients (52% men/48% women). Risk of bias was high in nonrandomized studies. Patients undergoing prehospital bypass and control patients had similar likelihoods of receiving EVT (odds ratio [OR] 1.52, 95% CI 0.98-2.35) or thrombolysis (OR 1.12, 0.92-1.35). Prehospital bypass was associated with earlier groin puncture (median difference -63.9 minutes, 95% CI -84.1 to -43.7). Time to needle in bypass patients was longer than in control patients in RCTs (median delay 34 minutes, 23.1-44.9 minutes), but similar in nonrandomized studies. Functional independence (modified Rankin Scale 0-2) at 90 days was more frequent in bypass patients (OR 1.23, 1.04-1.45). In patients with intracerebral hemorrhage, bypass was associated with increased mortality (risk ratio 1.30, 1.02-1.64). DISCUSSION: For patients with LVO stroke, benefits of expedited thrombectomy may outweigh possible risks associated with longer prehospital transport times. However, evidence is insufficient to recommend the routine implementation of prehospital bypass protocols. Further research is needed to determine circumstances under which direct access to comprehensive stroke centers should be prioritized for patients with severe stroke symptoms.