Simplified stroke imaging selection modality for endovascular thrombectomy in the extended time window: systematic review and meta-analysis

Background The impact of imaging selection modality on clinical outcomes of endovascular thrombectomy (EVT) in the 6–24-hour time window remains undetermined. We compared the clinical outcomes of a simplified stroke imaging selection modality using non-contrast computed tomography (NCCT)±CT angiography (CTA) with using advanced CT perfusion (CTP). Methods PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception to 1 May 2022 to compare NCCT±CTA and CTP for patient selection for EVT in late-presenting stroke with large vessel occlusions (LVO). The primary outcome was the proportion of patients achieving functional independence (modified Rankin Scale score 0–2) within 180 days. The secondary outcomes included mortality within 90 days, successful recanalization, and any intracranial hemorrhage. Results A total of 3419 patients in six articles were included in this meta-analysis. There was no significant difference between NCCT±CTA (no-CTP) and CTP in functional independence either in overall or subgroup analysis. However, the mortality in the no-CTP group was higher than in the CTP group. Furthermore, within the DAWN/DEFUSE 3-like subgroup, there were no significant differences in mortality, successful recanalization, and any intracranial hemorrhage between the two groups. Conclusion There was no significant difference between the simplified NCCT±CTA modality and the advanced CTP modality. The use of NCCT±CTA may represent a reasonable option for selecting patients for EVT in the extended time window, especially in the absence of CTP and acute phase MRI capabilities.