Comparison Of Drug-eluting Stent With Bare-metal Stent In Patients With Symptomatic Intracranial Atherosclerotic Stenosis

Objective:In-stent restenosis is an important reason for reducing the effect of interventional therapy for symptomatic intracranial atherosclerotic stenosis.In this study,we compared the in-stent restenosis rate and clinical efficacy of rapamycin-eluting stent and bare metal stent in the treatment of symptomatic intracranial atherosclerotic stenosis,and preliminarily explored the effect and application prospect of drug-eluting stents in the treatment of symptomatic intracranial atherosclerotic stenosis.Method:Patients with symptomatic intracranial atherosclerotic stenosis treated with balloon-expandable stents from July 2015 to December 2019 in the Affiliated Hospital of Qingdao University were selected as the research subjects.Patients were divided into rapamycin-eluting stent group and bare-metal stent group according to the type of stent selected during the operation.The clinical data of patients were collected,including age,sex,vascular risk factors(hypertension,diabetes,hyperlipidemia,smoking),onset forms(ischemic stroke,transient ischemic attack),National Institutes of Health Stroke scale,modified Rankin Scale,target lesion vascular location,Mori classification,preoperative target lesion vascular stenosis rate,postoperative residual stenosis rate,anesthesia methods(general anesthesia,local anesthesia),technical success rate,and incidence of perioperative complications.The clinical follow-up of all patients at 1 month,6 months and 1 year after surgery was observed,and the incidence of stroke(including hemorrhagic stroke,ischemic stroke)or transient ischemic attack between the two groups was recorded and compared.One year after surgery,digital subtraction angiography was followed up to record and compare the baseline data,clinical and imaging results of the two groups.Results:A total of 116 patients were enrolled,including 46 patients in the rapamycin-eluting stent group and 70 patients in the bare-metal stent group.Among all116 patients,the average age was 60.36±8.21 years,with 75(64.7%)males and 41(35.3%)females.There were no significant differences in age,sex,National Institutes of Health Stroke scale,modified Rankin score,hypertension,diabetes,hyperlipidemia,smoking,disease onset and other general clinical data between the two groups(P>0.05).Among all 116 patients,58(50.0 %)patients with target lesion vessels located in the anterior circulation and 58(50.0 %)patients in the posterior circulation.There was no significant difference in the specific segment of target lesion vessels(intracranial internal carotid artery,middle cerebral artery M1 segment,intracranial vertebral artery,basilar artery)and Mori classification between the two groups.There was no significant difference in preoperative target vascular stenosis rate,postoperative residual stenosis rate and intraoperative anesthesia methods between the two groups.The technical success rate was 100% in both groups.The perioperative complication rate was 4.3% in the rapamycin-eluting stent group and that of bare-metal stent group was 5.7%.There was no significant difference in the incidence of perioperative complications between the two groups.In the rapamycin-eluting stent group,there was 1 perioperative complication with NOVA stent and 1 with NANO stent,and the difference was not statistically significant(P>0.05).Among the 46 patients treated with rapamycin-eluting stent,there was no stroke or transient ischemic attack in 1 month and 6 months after surgery,and there was 1(2.2%)patient of ischemic stroke in 1 year.Among 70 patients treated with bare-metal stent,1(1.4 %)patient had ischemic stroke in 1 month after surgery,2(2.9 %)patients had transient ischemic attack in 6 months,and 6(8.6 %)patients had stroke or transient ischemic attack in 1 year,including 4 patients with ischemic stroke and2 patients with transient ischemic attack.There was no significant difference in the incidence of stroke or transient ischemic attack between the two groups at 1 month,6months and 1 year of clinical follow-up.A total of 66 patients in both groups underwent digital subtraction angiography 1 year after surgery,including 31(67.4 %)patients in the rapamycin-eluting stent group and 35(50 %)patients in the metal-bare stent group.There was no significant difference in the time interval of digital subtraction angiography between the two groups.There were 0(0%)patients with in-stent restenosis in the rapamycin-eluting stent group and 7(20.0%)patients with in-stent restenosis in the bare-metal stent group.The in-stent restenosis rate in the rapamycin-eluting stent group was significantly lower than that in the bare-metal stent group(P = 0.012),and the difference was statistically significant.Conclusions:The rapamycin-eluting stent has the same safety as the existing bare-metal stent in the treatment of symptomatic intracranial atherosclerotic stenosis,and it has a lower one-year in-stent restenosis rate than the bare-metal stent,showing a trend of further reducing the recurrence of ischemic stroke events.More long-term results need larger sample size and long-term follow-up to draw further conclusions.