Endovascular thrombectomy versus standard bridging thrombolytic with endovascular thrombectomy within 4·5 h of stroke onset: an open-label, blinded-endpoint, randomised non-inferiority trial.

BACKGROUND: The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy). METHODS: DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants. FINDINGS: Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84). INTERPRETATION: We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment. FUNDING: Australian National Health and Medical Research Council and Stryker USA.

Association of genetic variant and platelet function in patients undergoing neuroendovascular stenting.

INTRODUCTION: The risk of recurrent ischaemic events is related to platelet function, which is often assessed by thromboelastography (TEG). TEG has high interindividual variability. OBJECTIVE: To identify causal variants associated with TEG parameters in patients who receive aspirin and clopidogrel after intra- or extracranial stenting. METHODS: Patients who underwent stenting for extracranial or intracranial stenosis (70-99%) were recruited into the study. Blood samples were obtained for TEG to assess the platelet function before stenting. Aspirin- and clopidogrel-related genetic polymorphisms were determined by the MassARRAY method. Minor allele frequency and Hardy-Weinberg equilibrium (HWE) tests and linkage disequilibrium (LD) analysis were carried out. The influences of genetic polymorphism on TEG parameters were analysed by linear regression. RESULTS: A total of 249 patients were included in this study. Twenty-two selected single nucleotide polymorphisms (SNPs) were genotyped, and no significant deviation from HWE was found for any SNP in the study patients. Four SNPs-rs2104543, rs12772169, rs1998591 and rs1042194-within CYP2C18 were in high LD, and the genetic polymorphisms had a significant impact on the TEG parameters maximal clot strength (MAThrombin) and ADP-induced platelet-fibrin clot strength (MAADP). Patients who carried the loss-of-function CYP2C19*2 (rs4244285) allele were also at risk of increased MAThrombin and MAADP. CONCLUSIONS: Testing for these polymorphisms may be valuable in the identification of patients at high risk of recurrent ischaemic events. Alternative treatments may be considered for these high-risk patients. TRIAL REGISTRATION NUMBER: NCT01925872.

Effect of a Drug-Eluting Stent vs. Bare Metal Stent for the Treatment of Symptomatic Intracranial and Vertebral Artery Stenosis.

Background: For patients with symptomatic intracranial and vertebral artery stenosis who receive endovascular treatment, in-stent restenosis (ISR) is associated with the recurrence of ischemic stroke. This study evaluated a drug-eluting stent (DES) vs. bare metal stent (BMS) for the treatment of symptomatic intracranial and vertebral artery stenosis. Methods: The trial was a multicenter, 1:1 randomized, prospective feasibility clinical trial with 10 participating centers in China from March 2014 to October 2015. Eligible patients had symptomatic intracranial and vertebral artery stenosis (70%-99%) and had medical drug treatment failure. The primary endpoint was the rate of in-stent restenosis at 180 days of randomization. The secondary endpoint was a composite of the following two outcomes: (1) ischemic stroke or transient cerebral ischemia (TIA) in the same territory as the presenting event (distal to the target lesion) between 30 days and 1 year after randomization and (2) successful stent implantation. The safety outcome was the presence of stroke in any territory and death within 30 days of randomization or adverse events. Group t-tests or Wilcoxon rank-sum tests were used for the intergroup comparison of quantitative data according to the data distribution. The chi-square test or exact probability method was used for the classification data. The Wilcoxon rank-sum test or CMH test was used for the categorical data. Results: We enrolled 188 patients at 10 medical centers in China (92 assigned to the DES group and 96 to the BMS group). The mean age of the 188 study participants was 61.6 years (range, 38-75 years); 152 participants (80.9%) were male. There were 28 patients (43.8%) with an ISR at 180 days in the BMS group and 10 patients (14.5%) in the DES group [risk difference, 29.3% (95% CI, 14.5%-44.0%); P = 0.001]. The percent of patients with ischemic stroke or TIA in the same territory between 30 days and 1 year was 5.2% (5/96) in the BMS group and 2.2% (2/92) in the DES group [risk difference, 3.0%; (95% CI, -2.3% to 8.2%); P = 0.354]. The percent of patients with successful stent implantation was 99.0% (95/96) in the BMS group and 97.8% (90/92) in the DES group [risk difference, 1.1%; (95% CI, -1.7% to 3.9%); P = 0.584]. In total, five patients (5.2%) in the BMS group and three patients (3.3%) in the DES group [risk difference, 1.9%; (95% CI, -2.3% to 6.1%); P = 0.721] had stroke in any territory and death within the 30-day follow-up. Total adverse events occurred 167 times in 72 patients (75.0%) in the BMS group compared with 114 times in 59 patients (64.1%) in the DES group [risk difference, 10.9%; (95% CI, -0.1% to 21.7%); P = 0.115]. Conclusions: Among patients with symptomatic intracranial arterial stenosis and vertebral artery stenosis, the use of a drug-eluting stent compared with a bare metal stent resulted in a decreased risk of ISR, similar successful stent implantation, and similar adverse events. These findings support the use of a drug-eluting stent for patients with symptomatic intracranial arterial stenosis and vertebral artery stenosis. Clinical Trial Registration: http://www.chictr.org.cn/showproj.aspx?proj=148272, identifier: ChiCTR2200055925.

Corrigendum: Long-Term Risk Factors for Intracranial In-Stent Restenosis From a Multicenter Trial of Stenting for Symptomatic Intracranial Artery Stenosis Registry in China.

[This corrects the article DOI: 10.3389/fneur.2020.601199.].

Long-Term Risk Factors for Intracranial In-Stent Restenosis From a Multicenter Trial of Stenting for Symptomatic Intracranial Artery Stenosis Registry in China.

Background: For patients with symptomatic intracranial artery stenosis (sICAS), endovascular treatment has been shown to be feasible and safe in recent studies. However, in-stent restenosis (ISR) risks the recurrence of ischemic stroke. We attempt to elucidate the risk factors for ISR. Methods: We retrospectively analyzed 97 patients with sICAS from a prospective registry trial that included 20 centers from September 2013 to January 2015. Cases were classified into the ISR≥ 50% group or the ISR < 50% group. The baseline characteristics and long-term follow-up were compared between the two groups. Binary logistic regression analyses were identified as an association between ISR and endovascular technique factors. Results: According to whether ISR was detected by CT angiography, 97 patients were divided into the ISR group (n = 24) and the non-ISR group (n = 73). The admission baseline features and lesion angiography characteristics were similar, while plasma hs-CRP (mg/L) was higher in the ISR≥ 50% group at admission (8.2 ± 11.4 vs. 2.8 ± 4.1, p = 0.032). Binary logistic regression analysis identified the longer stents (adjusted OR 0.816, 95% CI 0.699-0.953; p = 0.010), balloon-mounted stents (adjusted OR 5.748, 95% CI 1.533-21.546; p = 0.009), and local anesthesia (adjusted OR 6.000, 95% CI 1.693-21.262; p = 0.006) as predictors of ISR at the 1-year follow-up. Conclusions: The longer stents, balloon-mounted stents implanted in the intracranial vertebral or basilar artery, and local anesthesia were significantly associated with in-stent restenosis. Further studies are required to identify accurate biomarkers or image markers associated with ISR in ICAS patients. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT01968122.

Early versus delayed stenting for intracranial atherosclerotic artery stenosis with ischemic stroke.

OBJECTIVE: To evaluate the clinical outcomes of early stenting (≤14 days) or late stenting (>14 days) in patients who underwent intracranial stent placement. METHODS: Patients with ischemic stroke caused by 70-99% intracranial atherosclerotic stenosis combined with poor collaterals were enrolled. The early stenting group, who underwent stenting within 14 days of last ischemic symptoms, were compared with the late stenting group who underwent stenting >14 days from last ischemic symptom. The patients were treated either with a balloon-mounted stent or a self-expanding stent as determined by the operators following a guideline. The baseline characteristics and clinical outcomes were evaluated and compared. RESULTS: One hundred and fifteen stroke patients were recruited into the study. Four patients (4/41) in the early stenting group and two patients (2/74) in the late stenting group were diagnosed with a cerebral vascular event associated with stenting within 3 days (p=0.184). In the long-term follow-up, eight patients in the early stenting group had restenosis ≥50%, which was higher than patients in the late stenting group (8/41 vs 4/74, p=0.018). The total rates of any ischemic stroke, transient ischemic attack, hemorrhagic stroke, and death in the early stenting group were higher than in the late stenting group (9/41 vs 6/74, p=0.035). The recurrence rate of ischemic stroke in the early stenting group was higher than in the late stenting group (5/41 vs 2/74, p=0.041). CONCLUSIONS: Stent placement in the setting of ischemic stroke caused by intracranial artery stenosis within 14 days may confer a higher risk of long-time cerebral vascular events and lead to a higher risk of restenosis. CLINICAL TRIAL REGISTRATION: NCT01968122.

Outcome of endovascular recanalization for intracranial in-stent restenosis.

BACKGROUND AND PURPOSE: In-stent restenosis (ISR) is one of the long-term adverse outcomes of endovascular angioplasty and stenting for symptomatic intracranial arterial stenosis. In this study, we try to evaluate the safety and efficacy of endovascular treatment for intracranial ISR. METHODS: We retrospectively collected patients with intracranial ISR who underwent endovascular treatment from June 2012 to August 2019 at a high-volume stroke center. Successful recanalization was defined as ≤30% residual stenosis. Stroke, myocardial infarction, and death after stenting within 30 days were used to evaluate periprocedural safety. Recurrent stroke in the territory of the culprit vessel and re-ISR in patients with clinical and vascular imaging follow-up data were used to evaluate the long-term outcome. RESULTS: 32 patients (59.6±7.2 years old) with ISR were recruited, including 22 patients (68.8%) treated with balloon dilatation, 8 patients (25%) with stenting, and 2 patients (6.3%) with failed procedures. Successful recanalization was achieved in 71.9% (23/32) of patients. There was no stroke, myocardial infarction or death within 30 days after the procedure. Recurrent stroke was found in 10.7% (3/28) of the patients, and re-ISR was found in 42.1% (8/19) of the patients. The re-ISR rate was lower in patients with stenting than in those with balloon dilatation (0% vs 57.1%, p=0.090), and in patients with successful recanalization than in those with unsuccessful recanalization (33.3% vs 75.0%, p=0.352), but with no statistically significant difference. CONCLUSIONS: The periprocedural safety of endovascular treatment for intracranial ISR may be acceptable, but the long-term rates of recurrent stroke and re-ISR remain at high levels.

Color Doppler imaging evaluation of proximal vertebral artery stenosis.

OBJECTIVE: The sonographic diagnostic criteria for vertebral artery stenosis have not been fully investigated. The purpose of this study was to assess hemodynamic parameters at color Doppler imaging and to determine, with digital subtraction angiography as the reference standard, the optimal thresholds for evaluation of proximal vertebral artery stenosis. MATERIALS AND METHODS: Among 653 patients with symptoms of ischemia of the posterior circulation, 247 subjects with normal arteries or stenosis of the proximal vertebral artery confirmed with digital subtraction angiography were included in the study. Peak systolic velocity at the origin of the vertebral artery (PSV(origin)) and in intervertebral segments of the vertebral artery (PSV(IV)), end-diastolic velocity at the origin and in the intervertebral segments of the vertebral artery, and the diameter of the vascular lumen were measured. The cutoff values for the diagnosis of < 50%, 50-69%, and 70-99% stenosis were determined with receiver operating characteristics analysis. RESULTS: The optimal cutoff values of hemodynamic parameters in evaluation of stenosis of the proximal vertebral artery for < 50% stenosis were PSV(origin) >or= 85 cm/s, PSV(origin) / PSV(IV) >or= 1.3, and end-diastolic velocity at the origin >or= 27 cm/s; for 50-69% stenosis were PSV(origin) >or= 140 cm/s, PSV(origin) / PSV(IV) >or/= 2.1, and end-diastolic velocity at the origin >or= 35 cm/s; and for 70-99% stenosis were PSV(origin) >or= 210 cm/s, PSV(origin) / PSV(IV) >or= 4.0, and end-diastolic velocity at the origin >or= 50 cm/s. PSV(origin) was the most useful hemodynamic parameter, having accuracy of 94.5%, 96.2%, and 88.7% for the diagnosis of < 50%, 50-69%, and 70-99% stenosis. CONCLUSION: Color Doppler imaging is a reliable method for evaluation of vertebral artery stenosis. The results derived from this study can be used as a reference for establishing sonographic criteria for proximal vertebral artery stenosis.

Treatment of symptomatic complex posterior circulation cerebral artery stenosis with balloon-mounted stents: technique feasibility and outcome.

PURPOSE: This study aimed to retrospectively analyze a series of patients with complex posterior circulation stenosis who underwent stent-assisted angioplasty to evaluate the feasibility of the procedure and summarize the experience with regard to complications. METHODS: A total of 16 consecutive patients with 27 complex posterior circulation artery stenoses refractory to medical therapy were enrolled. Technical success rate, periprocedural complication, and long-term follow-up result were evaluated. RESULTS: The study population included 16 patients with 27 lesions. A total of 36 stents were successfully implanted. The technical success rate was 100%, and the overall periprocedural complication rate was 12.5% (2/16). During a median of 25.5 months of follow-up, three patients presented recurrent transient ischemic attacks, which were confirmed had restenosis more than 50% by control angiography or transcranial Doppler. CONCLUSIONS: Stent-assisted angioplasty is a feasible treatment method for complex posterior circulation artery stenosis. However, it appears to be associated with a relatively high periprocedural complication rate. Therefore, strict periprocedural management to reduce mortality and morbidity is needed.

A rare case report of a mixed persistent proatlantal intersegmental artery.

Adults with persistent proatlantal intersegmental artery (PPIA) are rarely seen. We present a case of a special type of PPIA that was in a 57-year-old man who presented with dizziness and episodic vertigo of 9 months duration. The diagnosis relied on computed tomography angiography and digital subtraction angiography, by which a left internal carotid artery stenosis and an ipsilateral PPIA originating from the external carotid artery (ECA) was found. This special type of PPIA can be described as a ''mixed PPIA'' that originated as Type II from the ECA and coursed as Type I. The patient underwent carotid artery stenting and had no relapse during 3 months follow-up. In addition, the literatures on PPIA were reviewed.

Mechanical thrombectomy and rescue therapy for intracranial large artery occlusion with underlying atherosclerosis.

OBJECTIVE: To investigate the safety and efficacy of mechanical thrombectomy plus rescue therapy for intracranial large artery occlusion (ILAO) with underlying intracranial atherosclerosis (ICAS). METHODS: Patients enrolled in the intervention group of EAST (Endovascular Therapy for Acute ischemic Stroke Trial) were analyzed. For underlying ICAS identified during the stent retrieval procedure, rescue treatment was required for those with (1) a degree of arterial stenosis >70% or (2) any degree of arterial with blood flow impairment or (3) evidence of re-occlusion. Outcomes were compared between the ICAS group and the embolic group. Multivariate logistic regression was performed to determine independent predictors of functional independence at 90 days. RESULTS: Among the 140 patients included in the analysis, underlying ICAS was identified in 47 (34%), and 30 patients (21.4%) were considered to be eligible to receive rescue treatment. Of the 30 patients, 27 (90%) actually received rescue therapy. Recanalization rate (95.7% vs 96.8%, P=0.757) and functional independence at 90 days (63.8% vs 51.6%, P=0.169) were comparable between the ICAS group and the embolic group. No significant difference in symptomatic hemorrhage (4.3% vs 4.3%, P=1.000) or death (12.8% vs 12.9%, P=0.982) was found between the two groups. National Institutes of Health Stroke Scale score at presentation (OR=0.865, 95% CI 0.795 to 0.941; P=0.001) and modified Thrombolysis in Cerebral Infarction after the procedure (OR=2.864, 95% CI 1.018 to 8.061; P=0.046) were independently associated with functional independence at 90 days. CONCLUSIONS: Mechanical thrombectomy is safe in patients with ILAO with underlying ICAS. By employing a standard rescue therapy, favorable outcomes could be achieved in such patients. CLINICAL TRIAL REGISTRATION: NCT02350283 (Post-results).

Visual field impairment predicts recurrent stroke after acute posterior circulation stroke and transient ischemic attack.

AIMS: To evaluate whether visual field impairment (VFI) can predict stroke recurrence in patients with vertebral-basilar (VB) stroke. METHODS: A total of 326 patients were eligible for a VFI evaluation within 1 week of stroke onset. One-year follow-up data were obtained after VB stroke and other vascular events. All predictors were determined using Cox regression models. RESULTS: The overall incidence of recurrent VB stroke and transient ischemic attack (TIA) was 29% (n = 92). After multivariate adjustment, severe and moderate VFI were predictors of recurrent VB stroke and TIA. CONCLUSIONS: VFI is an independent predictor of recurrent VB stroke and TIA.

Association of thrombelastographic parameters with post-stenting ischemic events.

BACKGROUND AND PURPOSE: Thrombelastography (TEG) is widely used for the measurement of platelet function. However, few studies have investigated the TEG parameters in patients receiving extracranial or intracranial artery stenting for ischemic cerebrovascular disease. This study sought to describe the association of TEG parameters before the procedure with post-procedural ischemic events after extracranial or intracranial artery stenting. METHODS: Patients in whom stenting was performed for extracranial or intracranial artery stenosis (70-99%) were recruited into the study. Blood samples were obtained for TEG to assess platelet function before stenting. The primary endpoint was ischemic stroke or transient ischemic attack in the territory of the stented artery. RESULTS: A total of 218 patients were included in the study. During a mean follow-up period of 132 days (range 98-226 days), 18 (8.3%) primary endpoint events were recorded. Compared with patients without ischemic events, the ADP-induced platelet-fibrin clot strength (MAADP) was significantly higher (41.57±15.10 vs 33.50±13.86, p=0.020) and the ADP inhibition rate (ADP%) was significantly lower in patients with ischemic events (39.54±23.15 vs 55.29±24.43, p=0.009). Multivariate analysis identified MAADP and ADP% as significant independent predictors of subsequent ischemic events with HRs of 1.036 and 0.965, respectively. From receiver operating characteristic curve analysis, MAADP >49.95 mm had the best predictive value of ischemic events. CONCLUSIONS: Our study suggests that TEG parameters MAADP and ADP% are associated with subsequent ischemic events in patients with extracranial or intracranial stents. CLINICAL TRIAL NUMBER: NCT01925872.

The impact of P2Y12 promoter DNA methylation on the recurrence of ischemic events in Chinese patients with ischemic cerebrovascular disease.

The primary mechanism of clopidogrel resistance is still unclear. We aimed to investigate whether the methylation status of the P2Y12 promoter has effects on platelet function and clinical ischemic events. Patients with ischemic cerebrovascular disease were enrolled into our study. Venous blood samples were drawn for thrombelastograpy (TEG) and active metabolite assay. Patients were divided into a case- or control-group based on the occurrence of ischemic events during a one year follow-up. Two TEG parameters between the case and control groups were statistically significant [ADP inhibition rate (ADP%): P = 0.018; ADP-induced platelet-fibrin clot strength (MAADP): P = 0.030]. The concentrations of clopidogrel active metabolite had no significant difference (P = 0.281). Sixteen CpG dinucleotides on P2Y12 promoter were tested. Three CpG sites (CpG11 and CpG12 + 13) showed lower methylation status, which correlated with a strong association with increased risk of clinical events. Changes of MAADP and ADP% were also associated with methylation levels of CpG 11 and CpG 12 + 13. Hypomethylation of the P2Y12 promoter is associated with a higher platelet reactivity and increased risk of ischemic events in our patients. Methylation analysis of peripheral blood samples might be a novel molecular marker to help early identification of patients at high risk for clinical ischemic events.

Association of PON1, P2Y12 and COX1 with Recurrent Ischemic Events in Patients with Extracranial or Intracranial Stenting.

BACKGROUND AND PURPOSE: Short-term combined use of clopidogrel and aspirin improves cerebrovascular outcomes in patients with symptomatic extracranial or intracranial stenosis. Antiplatelet non-responsiveness is related to recurrent ischemic events, but the culprit genetic variants responsible for the non-responsiveness have not been well studied. We aimed to identify the genetic variants associated with poor clinical outcomes. METHODS: Patients with symptomatic extracranial or intracranial stenosis scheduled for stenting and receiving dual antiplatelets (clopidogrel 75 mg and aspirin 100 mg daily) for at least 5 days before intervention were enrolled. Ischemic events including recurrent transient ischemic attack, stroke, myocardial infarction, and vascular-related mortality within 12 months follow-up were recorded. We examined the influence of genetic polymorphisms on treatment outcome in our patients. RESULTS: A total of 268 patients were enrolled into our study and ischemic events were observed in 39 patients. For rs662 of paraoxonase 1 (PON1), allele C was associated with an increased risk of ischemic events (OR = 1.64, 95%CI = 1.03-2.62, P = 0.029). The A-allele carriers of rs2046934 of P2Y12 had a significant association with adverse events (OR = 2.01, 95%CI = 1.10-3.67, P = 0.041). The variant T-allele of cyclooxygenase-1 (COX1) rs1330344 significantly increased the risk of recurrent clinical events (OR = 1.85, 95%CI = 1.12-3.03, P = 0.017). The other single nucleotide polymorphism (SNP) had no association with ischemic events. CONCLUSIONS: PON1, P2Y12 and COX1 polymorphisms were associated with poorer vascular outcomes. Testing for these polymorphisms may be valuable in the identification of patients at risk for recurrent ischemic events.

[Evaluation by perfusion-weighted magnetic resonance to hemodynamic character and surgical effect of carotid system stenoses or occlusion].

OBJECTIVE: To evaluate hemodynamic character and surgical effect of stenoses or occlusion of carotid artery system by perfusion-weighted MRI. METHODS: Twenty-one patients with stenoses or occlusion of carotid artery system underwent surgical treatment. Two patients underwent endarterectomy, extracranial-intracranial arterial bypass to 10 patients, and percutaneous stent angioplasty to 9 patients. RESULTS: Preoperative perfusion-weighted magnetic resonance (MR) revealed normal regional cerebral blood flow in all patients, with delayed time to peak in both middle cerebral artery distribution and border zone. Postoperative perfusion-weighted MR revealed normal time to peak in border zone, but abnormal in middle cerebral artery distribution. Evaluated by perfusion-weighted MR, it showed that surgical method can improve the hemodynamic disorder of this kind of disease. The early curative effect of endarterectomy and percutaneous stent angioplasty is better than extracranial-intracranial arterial bypass. CONCLUSIONS: Perfusion-weighted MR is a good method to evaluate hemodynamic character of stenoses or occlusion of carotid artery system. Surgical method is helpful to this kind of disease, and its curative effect can be evaluated impersonally and accurately by this new technique.

[Percutaneous transluminal stenting for stenosis of internal carotid artery: a report of 355 cases].

OBJECTIVE: To discuss the benefits and complications of percutaneous transluminal stenting for stenosis of internal carotid artery (ICA). METHODS: 355 patients with ICA stenosis were included from 1997 to 2003. All of them took periprocedual anticoagulation treatment, cerebral vascular angiography and cervical Doppler sonography. 72 patients used cerebral protection of filter devices. Among the 283 patients without cerebral protection 202 patients (71.38%) underwent predilation, 66 patients (23.32%) underwent postdilation; and 3 patients underwent neither. RESULTS: The heart rates of 25.0% of all the patients decreased. Dislocation of microemboli happened in 5 patients. 2 of them improved after treatment. 3 of them got dyskinesia of one side. 2 patients (0.56%) died of intracerebral hemorrhage (ICH). 256 patients (84.77%) turned for the better. 260 patients (73.34%) were followed up. Restenosis occurred in 11 patients (4.23%). CONCLUSION: Percutaneous transluminal stenting for stenosis of internal carotid artery is safe if proper periprocedual treatment and operative procedure are taken. However, enough attention should be paid to the occurrence of ICH resulting from over-flow after operation.

[Combined intraarterial thrombolysis and intra-cerebral stent for acute ischemic stroke institute of brain vascular diseases].

OBJECTIVE: To test feasibility, safety and efficacy of combined intraarterial thrombolysis and intra-cerebral stent for acute ischemic stroke. METHODS: From 2001-5 to 2002-8, 19 patients with acute onset of stroke were treated with intraaterial thrombolysis followed by intra-cerebral stent. 9 located in middle cerebral artery (MCA), 10 located in basal artery (BA). For each patient, intraarterial thrombolysis of MCA or BA was applied at first, stent angioplasty was applied at the stenosis left after the thrombolysis by using the stent for coronary artery. RESULTS: All the 19 patients left stenosis after intraaterial thrombolysis, and the average stenosis was 85% in diameter. After the operation of stent, the images showed the vascular is smooth and had no stenosis left. The symptoms were disappeared or improved. Thrombus formation in the stent occurred on 1 patient 24 hours after the operation. TIA never occurred in the left 18 patients then. TCD follow up showed blood flow is normal. CONCLUSIONS: It is feasibility of intraaterial thrombosis followed by intra-cerebral stent. And it is valid for preventing occlusion again of the vessel and decreasing the rate of TIA occurring.

[Complications of stent-assistant angioplasty of symptomatic intracranial artery stenosis].

OBJECTIVE: To discuss the safety of intracranial stenting for refractory symptomatic intracranial artery stenosis. METHODS: Forty-eight patients with symptomatic intracranial artery stenosis were treated by transluminal stent-assistant angioplasty. Of them, 40 cases were selected because they had recurrent TIAs or mild stroke despite of antiplatelet or anticoagulation therapy; 8 cases with high-grade stenosis after acute cerebral artery theromblysis. Lesions involved MCA (17/48); Basilar artery (8/48); intracranial vertebral artery (18/18); and distal ICA (5/18). RESULTS: For 46 of 48 cases the flexible coronary stent were successfully deployed. The average stenosis reduced from 83% to 5%, short-term follow-up showed good clinical improvement. Complications include vessel rupture (1/18); acute thrombosis within stent (1/48); perforation of cortical artery (1/18) and perforate vessel occlusion (1/18). CONCLUSION: Stent-assistant angioplasty are effective for treatment of symptomatic intracranial stenosis, the higher rate of complications may be because of the limited experiences of this technique. it need further practise and long term follow-up study.

Entrapment of a micro-guidewire during stenting of basilar stenosis.

Entrapment of a microwire related to intracranial endovascular therapy is an uncommon complication. A 64-year-old man with symptomatic basilar artery stenosis was treated with stenting. A 300 cm Synchro microwire became trapped in the P1 segment of the left posterior cerebral artery during the procedure. The decision was made to leave the microwire in place, considering that aggressive retrieval procedures could cause injury to the cerebral vasculature. The entrapped microwire was later inadvertently dislocated and removed while pulling the microwire back into the femoral artery with a looped catheter from the left femoral access. This demonstrates that, although entrapment of a microwire during endovascular therapy is a rare event, an optimal salvage technique needs to be explored further.