Analysis Of Factors Affecting Outcomes After Endovascular Treatment For Acute Basilar Artery Occlusion

In 2009,the BASICS study suggested that endovascular treatment(EVT)for acute basilar artery occlusion(BAO)did not significantly improve patients’ outcomes compared with medical therapy.Several high-quality studies on EVT for large vessel occlusion in anterior circulation published in the New England Journal of Medicine since 2015 had shown that EVT combined with medical treatment was more effective than medical treatment alone.Once again,it had set off a climax of EVT for acute intracranial large vessel occlusion.Besides,the researches on endovascular therapy for BAO were also increased,such as ENDOSTROKE study,BASILAR study,BEST study,and BASICS study.Although the results were not consistent,a growing number of studies had demonstrated the efficacy and safety of EVT for BAO.For acute BAO,what is the relationship between different reperfusion levels and outcomes after endovascular therapy? Why still do a large proportion of patients fail to achieve favourable outcomes after successful recanalization? What are the predictive factors? Our study will focus on the above issues.Part1: Analysis of the relationship between Extended Thrombolysis In Cerebral Infarction grades and outcomes after endovascular therapy for acute basilar artery occlusionBackground: Referfusion grade is an important factor associated with clinical outcomes after endovascular treatment for patients with acute intracranial large vessel occlusion.The thrombolysis in cerebral infarction(TICI)scale is the most commonly used scale to evaluate reperfusion after endovascular intervention.The extended thrombolysis in cerebral infarction(e TICI)scale was reformed from TICI scale with the addition of a TICI2 c category.Higher e TICI grades are associated with better clinical outcomes after endovascular treatment(EVT)for proximal intracranial occlusion of the anterior circulation.However,with regard to posterior circulation,the relationship between e TICI grades and outcomes after EVT in patients with acute basilar artery occlusion(BAO)remained unclear.We aimed to explore the association between e TICI grades and outcomes and to answer which e TICI category was the cut-off correlating with better clinical outcomes after EVT for patients with acute BAO.Methods: We included patients treated with EVT from the BASILAR(Assessment of Endovascular Treatment for Acute Basilar Artery Occlusion via a Nationwide Prospective Registry)study,which was a non-randomized controlled,multi-center observational study.We consecutively enrolled adult patients with symptomatic basilar artery occlusion confirmed by computed tomographic angiography(CTA)or magnetic resonance angiography(MRA)or digital substraction angiography(DSA)and underwent EVT within 24 hours of stroke onset.Patients were divided into four groups based on e TICI categories,including e TICI0-2a,e TICI2 b,e TICI2 c,and e TICI3.Multivariable logistic regression analyses were performed to assess the impact of e TICI grades on 90-day favourable functional outcomes,defined as a modified Rankin Scale(m RS,7 levels from 0 to 6,0 means asymptomatic,higher score means more severe disability,and the 6 indicates death)score of 0-3.Other outcomes were functional independence(m RS,0-2),all-cause mortality,and symptomatic intracranial haemorrhage.We also analysed the association between different e TICI grades and clinical outcomes(m RS score 0-3,m RS score 0-2,mortality)one year after EVT.Results: We successfully enrolled 647 cases.And 483(74.7%)were male,the median age was 64(interquartile range: 56-73)years old.Among 647 patients treated with EVT,127(19.6%),128(24.5%),110(21.1%),and 282(54%)patients achieved e TICI grades of 0-2a,2b,2c,and 3,respectively.Compared with e TICI grades 0-2a,higher rates of favourable functional outcomes(adjusted OR and 95% CI,2.96 [1.33-6.57] and 7.40 [3.63-15.09],respectively)were observed for grades 2c and 3,not 2b(adjusted OR and 95% CI,1.93[0.86-4.36]).The risks of mortality and symptomatic intracranial haemorrhage were also lower for e TICI grades 2c and 3 than for grades 0-2a.Among the 615 patients who completed1-year follow-up,higher e TICI grades were associated with better clinical outcomes.Conclusions: e TICI grade of 2c or 3 may be the target for successful reperfusion after EVT in patients with acute BAO;however,The findings of this study need to be further verified by multi-center randomized controlled trials.Part2: Analysis of Predictive Factors of Futile Recanalization after Endovascular Treatment for Acute Basilar Artery OcclusionBackground and purpose: Benefited from the accumulation of neurointerventionalists’ experience and the continuous update of interventional devices,rate of successful recanalization was increasing after endovascular treatment(EVT)in patients with acute basilar artery occlusion(BAO).However,even if the occluded vessel was completely recanalized,only about half of the patients with BAO achieved favourable clinical outcomes.The purpose of our study was to evaluate and analyse the predictive factors associated with "futile recanalization" after EVT for patients with acute BAO.Methods:The study data was derived from the BASILAR(Assessment of Endovascular Treatment for Acute Basilar Artery Occlusion via a Nationwide Prospective Registry)study,a nationwide,multicenter,non-randomized controlled,observational study.Patients underwent EVT after acute BAO were enrolled,and all of these patients achieved complete recanalization(e TICI3)after EVT.Futile recanalization was defined as a postoperative reperfusion level of e TICI3 with poor outcome(90-day m RS score 4-6).Predictive factors affecting futile recanalization were assessed by logistic regression analysis.We also analyzed predictors of futile recanalization in patients with e TICI2b-3 and e TICI2c/3 reperfusion.Outcomes: We enrolled 522 patients with eTICI2b-3 reperfusion after endovascular therapy,including 394 patients with e TICI2c/3 reperfusion and 284 patients with e TICI3 reperfusion.According to 90-day m RS score of 4-6 or 0-3,patients were divided into futile recanalization groups and control groups.Multivariate Logistic regression analysis showed that for patients with complete recanalization,higher baseline NIHSS score(adjusted odds ratio,95% confidence interval,1.10 [1.06-1.14];P < 0.001),lower pc-ASPECTS(adjusted odds ratio,95% confidence interval,0.61 [0.49-0.77];P < 0.001),collateral score ASITN/SIR grade 0-1(adjusted odds ratio,95% confidence interval,3.52 [1.10-11.29];P=0.035),history of diabetes(adjusted odds ratio,95% confidence interval,2.87 [1.30-6.33];P = 0.009)and longer time from arterial puncture to recanalization(adjusted odds ratio,95%confidence interval,1.01[1.00-1.01];P=0.041)were independent predictive factors of futile recanalization.Higher baseline NIHSS score,lower pc-ASPECTS and ASITN/SIR score 0-1 were also significantly associated with futile recanalization in e TICI2b-3 and e TICI2c/3patients.Conclusion: Despite complete recanalization,a large proportion of patients received endovascular therapy after acute BAO failed to achieve favourable clinical outcome.The severity of cerebral infarction,longer time from puncture to recanalization,poorer collateral circulation,and history of diabetes mellitus may be correlated with futile recanalization.Our results need to be confirmed by further large randomized controlled studies.