Effect of thrombectomy on oedema progression and clinical outcome in patients with a poor collateral profile

Background and purpose The impact of the cerebral collateral circulation on lesion progression and clinical outcome in ischaemic stroke is well established.Moreover,collateral status modifies the effect of endovascular treatment and was therefore used to select patients for therapy in prior trials.The purpose of this study was to quantify the effect of vessel recanalisation on lesion pathophysiology and clinical outcome in patients with a poor collateral profile.Materials and methods 129 patients who had an ischaemic stroke with large vessel occlusion in the anterior circulation and a collateral score(CS)of 0-2 were included.Collateral profile was defined using an established 5-point scoring system in CT angiography.Lesion progression was determined using quantitative lesion water uptake measurements on admission and follow-up CT(FCT),and clinical outcome was assessed using modified Rankin Scale(mRS)scores after 90 days.Results Oedema formation in FCT was significantly lower in patients with vessel recanalisation compared with patients with persistent vessel occlusion(mean 19.5%,95%CI:17%to 22%vs mean 27%,95%CI:25%to 29%;p<0.0001).In a multivariable linear regression analysis,vessel recanalisation was significantly associated with oedema formation in FCT(ß=−7.31,SD=0.015,p<0.0001),adjusted for CS,age and Alberta Stroke Program Early CT Score(ASPECTS).Functional outcome was significantly better in patients following successful recanalisation(mRS at day 90:4.5,IQR:2-6 vs 5,IQR:5-6,p<0.001).Conclusion Although poor collaterals are known to be associated with poor outcome,endovascular recanalisation was still associated with significant oedema reduction and comparably better outcome in this patient group.Patients with poor collaterals should not generally be excluded from thrombectomy.

Haemorrhage after thrombectomy with adjuvant thrombolysis in unknown onset stroke depends on high early lesion water uptake

Background and purpose In wake-up stroke,CT-based quantitative net water uptake(NWU)might serve as an alternative tool to MRI to guide intravenous thrombolysis with alteplase(IVT).An important complication after IVT is symptomatic intracerebral haemorrhage(sICH).As NWU directly implies ischaemic lesion progression,reflecting blood-brain barrier injury,we hypothesised that NWU predicts sICH in patients who had a ischaemic stroke undergoing thrombectomy with unknown onset.Methods Consecutive analysis of all patients who had unknown onset anterior circulation ischaemic stroke who underwent CT at baseline and endovascular treatment between December 2016 and October 2020.Quantitative NWU was assessed on baseline CT.The primary endpoint was sICH.The association of NWU and other baseline parameters to sICH was investigated using inverse-probability weighting(IPW)analysis.Results A total of 88 patients were included,of which 46 patients(52.3%)received IVT.The median NWU was 10.7%(IQR:5.1–17.7).The proportion of patients with any haemorrhage and sICH were 35.2%and 13.6%.NWU at baseline was significantly higher in patients with sICH(19.1%vs 9.6%,p<0.0001)and the median Alberta Stroke Program Early CT Score(ASPECTS)was lower(5 vs 8,p<0.0001).Following IPW,there was no association between IVT and sICH in unadjusted analysis.However,after adjusting for ASPECTS and NWU,there was a significant association between IVT administration and sICH(14.6%,95%CI:3.3%to 25.6%,p<0.01).Conclusion In patients with ischaemic stroke with unknown onset,the combination of high NWU with IVT is directly linked to higher rates of sICH.Besides ASPECTS for evaluating the extent of the early infarct lesion,quantitative NWU could be used as an imaging biomarker to assess the degree of blood-brain barrier damage in order to predict the risk of sICH in patients with wake up stroke.