Mechanical Thrombectomy in Extended Time Window: Real-World Data from a Colombian Stroke Center

BackgroundMechanical thrombectomy (MT) has revolutionized the management of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), particularly when performed within the first 6 hours after symptom onset. The development of perfusion imaging software has enabled patient selection to thrombectomy for up to 24 hours in selected cases with salvageable brain tissue, following the criteria of trials such as DEFUSE 3. However, the real-world application of these criteria, remains understudied. ObjectiveTo determine the clinical outcomes of patients with AIS treated with MT in an extended window (>6 hours), comparing patients who met DEFUSE 3 perfusion criteria versus those who did not. MethodsA retrospective analysis was conducted on patients undergoing MT between 6 and 24 hours after symptom onset. Clinical outcomes were assessed at hospital discharge and 90 days using the modified Rankin Scale (mRS). Patients were divided into two groups based on whether they met DEFUSE 3 perfusion criteria. ResultsA total of 80 patients were treated. Median age was 76 years (IQR 62,5-83). Wake-up strokes accounted for 45. Median ASPECTS score was 7 (SD 2.25) and median ischemic core volume was 18.9 ml (IQR 8,2 - 44,7). Of 76 patients analyzed, 37 (48.7%) met DEFUSE 3 criteria and 39 (51.3%) did not. Although patients meeting the criteria showed a trend toward better functional outcomes (mRS 0-3 at discharge: 66.6% vs 33.3%; p = 0.14), similar outcomes were observed at 90 days (63.6% vs 36.3% p = 0.34). Additionally, the group that did not meet DEFUSE 3 criteria had a higher proportion of wake-up strokes (p = 0.02), a relevant factor in extended-window decision-making. No statistically significant differences were found in mortality or severe disability between groups. ConclusionIn our study a good functional outcomes was more frequent in patients selected by DEFUSE 3 perfusion criteria, but a notable number of patients outside these criteria also achieved functional recovery. These findings support a more flexible and context-aware approach to patient selection in extended windows. Future prospective studies should aim to refine patient selection protocols that balance safety, efficacy, and accessibility.