Pathology,Imaging Marker Of Thrombus And Clinical Outcomes Of Acute Ischemic Stroke After Reperfusion Therapy

Purpose:This study aimed to evaluate the presence of antegrade flow in acute ischemic stroke(AIS)patients with large vessel occlusion(LVO),and further to determine its relationship with clinical outcomes after reperfusion therapyMethods:We retrospectively reviewed our database of AIS patients who received reperfusion therapy from May 2009 to December 2020.Patients with unilateral internal carotid artery(ICA)or M1 segment of middle cerebral artery(MCA)occlusion confirmed by dynamic computer tomography angiography(CTA)were included.We defined antegrade flow as early opacification at the distal interface of the clot with subsequent distal extension on dynamic CTA,and retrograde flow as opacification from the distal branches to the occluded vessel segment on dynamic CTA.Good outcome was defined as modified Rankin Scale(m RS)score ≤ 2 at 3months.European Cooperative Acut Stroke Study(ECASS)II criteria was used to evaluate hemorrhagic transformation at 24 hours after reperfusion therapy.Logistic regression was used to analyze the relationship of antegrade flow with good outcome and hemorrhagic transformation.Results:A total of 480 patients were enrolled.Aantegrade flow was found in 234(48.8%)patients and 165(34.4%)patients had good outcome.In univariate analysis,patients with antegrade flow had a higher rate of good outcome(44.0% vs 25.2%,p < 0.001)and a lower rate of hemorrhagic transformation(41.2% vs 58.8%,P = 0.001)compared with patients with retrograde flow.Antegrade flow was an independent predictor for good outcome in AIS patients(OR=1.981;95% CI: 1.198,3.278;P =0.008).No significant association of hemorrhage transformation at 24 hours was found with anterograde flow.Subgroup analysis found that patients with anterograde flow had a significantly lower rate of parenchymal hemorrhage(PH)compared with patients with retrograde flow among patients who received mechanical thrombectomy(20.3% vs 50.7%;or = 0.404;95% CI: 0.193,0.847;p = 0.016).Conclusion:Patients with antegrade flow are more likely to have a good outcome in AIS patients with large vessel occlusion after reperfusion therapy.Furthermore,patients with antegrade flow are less likely to occur parenchymal hematoma among patients who received mechanical thrombectomyPurpose:To evaluate the thrombus permeability of AIS patients and explore its relationship with antegrade flow.Methods:We retrospectively reviewed our database of AIS patients who received reperfusion therapy from May 2009 to December 2020.Patients with unilateral intracranial segment of ICA occlusion or M1 segment of MCA occlusion confirmed by dynamic CTA were included.Thrombus permeability was defined as thrombus attenuation increase(TAI),which was the increase of Hounsfield unit(HU)in the thrombus between two phases of dynamic CTA: 1)at the first phase and 2)at the 13 th phase(the mean peak arterial phase).Antegrade flow was defined as early opacification in the distal to the clot and then extending more distally.Logistic regression was used to analyze the relationship between antegrade flow and thrombus permeability.Results:A total of 277 patients were included,and the mean age was 70±14 years.Among them,127(45.8%)were female,and 169(61.0%)patients received mechanical thrombectomy.Antegrade flow was observed in 126(45.5%)patients on dynamic CTA.The median TAI was 14.2(2.4-27.2)HU.Univariate analysis showed that patients with antegrade flow had a higher median TAI compared with patients with retrograde flow(26.8 HU vs 5.9 HU,p < 0.001).TAI was independently associated with antegrade flow(OR=1.071;95% CI: 1.051,1.092;p < 0.001).Conclusion:AIS patients with high thrombus permeability are more likely to present antegrade flow.Purpose:We aimed to observe the thrombus structure of AIS patients by scanning electron microscope(SEM),and further to explore the relationship between thrombus structure and permeability.Methods:We retrospectively reviewed our database of AIS patients who received mechanical thrombectomy from October 2018 to December 2020.Patients with unilateral intracranial segment of ICA or M1 segment of MCA occlusion confirmed by dynamic CTA were included.The thrombus was observed under high-resolution scanning electron microscope(SEM).The erythrocyte,fibrin and porosity in the thrombus were quantitatively analyzed.Dense thrombus was defined as porosity of thrombi ≤ 0.019.Thrombus permeability was defined as thrombus attenuation increase(TAI),which was the increase of Hounsfield unit(HU)in the thrombus between two phases of dynamic CTA: 1)at the first phase and 2)at the 13 th phase(the mean peak arterial phase).Logistic regression and linear regression were used to analyze the relationship between thrombus structure and thrombus permeability and the effect of thrombus structure on mechanical thrombectomy.Results:A total of 33 patients were included.The mean age was 69±11 years and 11patients(33.3%)were female.Among them,22(66.6%)patients received intravenous thrombolysis before thrombectomy,and 17(51.5%)patients had dense thrombus.Multiple linear regression analysis showed that dense thrombus was negatively correlated with thrombus permeability(β =-24.536;95% CI:-40.623,-8.450;p =0.007).Patients with dense thrombus had lower proportion of patients with puncture to reperfusion time > 60 minutes(17.6% vs 68.8%;OR = 0.027;95% CI: 0.001,0.523;p = 0.017)and less likely to require three or more attempts for recanalization(37.5%vs 76.5%;OR = 0.126;95% CI: 0.018,0.880;p = 0.037)compared with patients with non-dense thrombus.Conclusion:AIS patients with dense thrombus showed lower thrombus permeability and were easier to achieve recanalization through mechanical thrombectomy...