Observational Study On Rescue Endovascular Treatment Of Acute Ischemic Stroke Due To Anterior Circulation Large Artery Occlusion

Part One Rescue Mechanical Thrombectomy for Patients with Early Neurological Deterioration after Acute Mild Ischemic Stroke due to Large Artery OcclusionObjective To evaluate the efficacy and safety of rescue mechanical thrombectomy in patients with acute mild ischemic stroke and large artery occlusion after early neurological deterioration(END).Materials and Methods Patients with acute ischemic stroke were enrolled from six large comprehensive hospitals in this study.Computed tomographic angiography(CTA)or magnetic resonance angiography(MRA)were used to select ischemic stroke patients caused by anterior circulation large artery occlusion;National institutes of health stroke scale(NIHSS)and clinical system evaluation were used to select patients with mild ischemic stroke and END occurred.The diagnostic criteria for mild ischemic stroke was NIHSS under 6 points.The diagnostic criteria for END was NIHSS increased at least 4 points within 72 hours after admission.The enrolled patients underwent a computed tomography(CT)scan of head after END and patients with Alberta Stroke Program Early CT Score(ASPECTS)under 7 points were excluded.Patients were divided into two groups based on whether rescue mechanical thrombectomy was performed.One group of patients was medical management alone;and the other group was given medical management and rescue mechanical thrombectomy.Neurological function was assessed with modified Rankin Scale(m RS)at 90 days after stroke onset.Favorable functional outcome was defined as m RS score of 0~2 and excellent functional outcome was defined as m RS score of 0~1.At the same time,CT was used to evaluate the occurrence of intracranial hemorrhage and symptomatic intracranial hemorrhage(s ICH).The proportions of favorable functional outcome,excellent functional outcome and s ICH in the two groups were compared by the chi-square test.Propensity score matching was performed to further analyze the efficacy indexes and safety indexes of the two groups.Results A total of 134 patients with END after acute mild stroke were enrolled in the study.Among them,45 patients(33.6%)received rescue mechanical thrombectomy and 89(66.4%)received medical management alone.Compared with the medical management group,the rescue mechanical thrombectomy group had a shorter time from onset to END(12,7-23 versus 18,11-41;P=0.004).In the propensity score matching analysis,compared with the medical management alone,patients with favorable functional outcome(m RS score of 0 to 2 at 90 days)was more in the rescue mechanical thrombectomy group((51.2% versus 26.8%;P=0.024),and excellent functional outcome(m RS score of 0 to 1 at 90 days)was more in the rescue mechanical thrombectomy group(39% versus 7.3%;P=0.001).Between the rescue mechanical thrombectomy group and the medical management alone group,there was no significant difference in s ICH after stroke onset(4.9% versus 0.0%;P=0.494),and there was no significant difference in mortality at 90 days after stroke onset(4.9% versus 4.9%;P=1.000).Conclusion Rescue mechanical thrombectomy may be safe and effective for patients with END after acute mild ischemic stroke due to anterior circulation large vessel occlusion,and further randomized controlled trials are necessary.Part Two Safety of Intra-arterial Tirofiban Administration in Acute Ischemic Stroke Patients after Unsuccessful Mechanical ThrombectomyPurpose To assess safety of low-dose intra-arterial(IA)tirofiban bolus following unsuccessful mechanical thrombectomy in patients with acute ischemic stroke due to large artery occlusion in anterior cerebral circulation.Materials and Methods Patients with acute ischemic stroke and treated with mechanical thrombectomy were enrolled in 21 comprehensive hospitals.Low-dose tirofiban was infused via a microcatheter near the occlusion in patients following unsuccessful mechanical thrombectomy.The major safety measurement was defined as s ICH.The functional outcome at 90 days was assessed with m RS,and a score of 0~2 was defined as favorable.Results Of the 632 enrolled patients,154(24.4%)received IA tirofiban treatment.s ICH rate was 13.6%(21/154)in patients with tirofiban,and 16.7%(80/478)in patients without tirofiban(P=0.361).IA tirofiban was not associated with increased risk of s ICH(odds ratio [OR],0.69;95% confidence interval [CI],0.36-1.31,P=0.26).IA tirofiban treatment did not increase the risk of mortality at 90 days of the index stroke(OR,0.66;95% CI,0.36-1.31,P=0.15).Patients with large artery atherosclerosis stroke and treated with tirofiban were associated with decreased risk of death(11.3% versus 23.4%,P=0.042)compared with those who were untreated with tirofiban.Conclusion Low-dose IA tirofiban administration may be relatively safe in patients with acute ischemic stroke following unsuccessful recanalization.The efficacy should be confirmed by a large randomized controlled trial.Part Three Comparison of Two Rescue Stenting for Acute Anterior Circulation Intracranial Large Artery Occlusion after Failed Mechanical ThrombectomyPurpose The efficacy and safety of Solitaire stent release and self-expanding stent placement as two rescue recanalization measures were compared in patients with acute anterior circulation intracranial large artery occlusion after failed mechanical thrombectomy.Materials and Methods Patients with acute ischemic stroke due to acute anterior circulation intracranial large artery occlusion were enrolled in eight comprehensive hospitals.Solitaire stent release or self-expanding stent placement as rescue recanalization measure was determined by the interventionalist after failed mechanical thrombectomy.Vascular recanalization was evaluated using modified Thrombolysis in Cerebral Infarction(m TICI)score.NIHSS was used to assess the severity of stroke at admission and the clinical outcomes of 24 hours after operation and 5-7 days after operation,or at discharge.The neurological function was evaluated by m RS 90 days after operation,and s ICH after operation was assessed by CT.Results A total of 93 patients with acute anterior circulation intracranial large artery occlusion after failed mechanical thrombectomy were included in this study.Among them,77(82.8%)patients were treated with Solitaire stents,and 16(17.2%)patients were treated with self-expanding stents.There was no significant difference in the proportion of m TICI 2b or 3 recanalization after Solitaire stent dislocation and self-expanding stent placement(77.9% versus 100%;P=0.085).There was no significant difference about NIHSS at 24 hours after operation(14,9-22 versus 13,8-18;P=0.308).There was no significant difference about NIHSS at 5~7 days after operation,or at discharge(11,4-18 versus 8,5-21;P=0.736).There was no significant difference about favorable functional outcome(90 days m RS 0~2)between the two groups(40.3% versus 33.3%,P=0.615).There was no significant difference about s ICH between the two groups(9.1% versus 18.8%,P=0.489).There was no significant difference about mortality at 90 days between the two groups(26.0% versus 12.5%,P=0.406).Conclusion The safety and efficacy of Solitaire stent delivery and rescue intracranial self-expanding stenting are comparable for patients with acute ischemic stroke due to anterior circulation intracranial large artery occlusion after failed mechanical thrombectomy.