Zhongrong Miao

Impact of collaterals on the efficacy and safety of endovascular treatment in acute ischaemic stroke: a systematic review and meta-analysis

Objective We aimed to investigate the role of pretreatment collateral status in predicting the efficacy and safety of endovascular treatment (EVT) in acute ischaemic stroke due to cervical and/or cerebral arterial occlusions. Methods Relevant full-text articles published since 1 January 2000, investigating correlations between collateral status and any efficacy or safety outcome in patients undergoing EVT in cohort or case–control studies, or randomised clinical trials, were retrieved by PubMed and manual search. Two authors extracted data from eligible studies and assessed study quality. Risk ratios (RR) were pooled for good versus poor collaterals for outcomes based on a random-effects model. Sensitivity and subgroup analyses were conducted. Results In total, 35 (3542 participants) and 23 (2652 participants) studies were included in qualitative review and quantitative meta-analysis, respectively. Overall, good pretreatment collaterals increased the rate of favourable functional outcome at 3 months (RR=1.98, 95% CI 1.64 to 2.38; p<0.001), and reduced the risks of periprocedural symptomatic intracranial haemorrhage (RR=0.59, 95% CI 0.43 to 0.81; p=0.001) and 3-month mortality (RR=0.49, 95% CI 0.38 to 0.63; p<0.001), as compared with poor collaterals, in patients with acute ischaemic stroke under EVT. No individual study could alter the estimate of overall effect of collateral status, but there were moderate to significant heterogeneities between subgroups of studies with different modes of EVT, different arterial occlusions and different collateral grading methods. Conclusions Good pretreatment collateral status is associated with higher rates of favourable functional outcome, and lower rates of symptomatic intracranial haemorrhage and mortality, in patients with acute ischaemic stroke receiving endovascular therapies.

Outcomes of tailored angioplasty and/or stenting for symptomatic intracranial atherosclerosis: a prospective cohort study after SAMMPRIS

Background and purpose High periprocedural complication rate is a key limitation of endovascular treatment of intracranial atherosclerotic disease (ICAD), despite potential risk reduction of recurrent stroke. Taking lessons from the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Arterial Stenosis (SAMMPRIS) trial, targeting a selected patient population, we prospectively evaluated the feasibility and safety of tailored angioplasty and/or stenting for patients with ICAD. Methods From November 2011 to October 2012, 158 patients with symptomatic ICAD caused by hypoperfusion combined with poor collateral flow were consecutively recruited into a prospective single center study. Patients were divided into three groups based on arterial access and lesion morphology: balloon mounted stent group (group BS) for smooth access and Mori A lesion, angioplasty plus self-expanding stent group (group AS) for tortuous access and Mori B or C lesion, and angioplasty group (group AG) for tortuous access and Mori A lesion. The primary endpoints were successful procedure rate and any vascular event within 30 days. Results Overall technical success rate was 96.3% (154/158). There were significant differences in the technical success rate: 89.7% (35/39) in group AG compared with 97.5% (79/81) in group BS and 100% (38/38) in group AS (p=0.042). The 30 day composite stroke, myocardial infarction, or death rate was 4.4% (7/158). Stroke within 30 days occurred in four patients in group BS and in three patients in group AS. Conclusions Individualized treatment of ICAD using tailored devices according to arterial access and lesion morphology was feasible and safe in symptomatic patients caused by hypoperfusion with poor collateral flow.

Impact of Collateral Status on Successful Revascularization in Endovascular Treatment: A Systematic Review and Meta-Analysis.

Background: Pre-treatment collateral status may be associated with the rates of successful revascularization in acute ischemic stroke patients receiving endovascular treatment (EVT). We conducted a systematic review and meta-analysis to synthesize relevant evidence currently available. Methods: Relevant full-text articles published in English since January 1, 2000, reporting associations between collateral status and successful reperfusion and/or recanalization in acute ischemic stroke patients receiving EVT in cohort or case-control studies, or randomized clinical trials, were retrieved through search of PubMed. Study selection, data extraction and study quality assessment were carried out by 2 investigators. Risk ratios (RR) were pooled for good vs. poor collaterals for the outcomes of successful reperfusion and recanalization, based on random-effects models. Subgroup analyses were conducted to explore for potential factors that might interfere with the effects of pre-treatment collateral status on reperfusion by EVT. Results: In total, 27 studies (2,366 subjects) were included in qualitative analysis, among which 24 studies (2,239 subjects) were quantitatively analyzed. Overall, good pre-treatment collaterals significantly increased the rate of both successful reperfusion (RR 1.28, 95% CI 1.17-1.40; p < 0.001) and recanalization (RR 1.23, 95% CI 1.06-1.42; p = 0.006), as compared with poor collaterals. Subgroup analyses revealed that the effects of collateral status on successful reperfusion by EVT might be different between populations with different ethnicities. Conclusions: Good pre-treatment collaterals may enhance the rates of successful reperfusion and recanalization in EVT for acute ischemic stroke. This may partly explain the favorable effects of good pre-treatment collaterals on clinical outcomes of stroke patients receiving EVT. Thus, it would be valuable to assess the collateral status prior to EVT in acute ischemic stroke. But studies are needed to further verify if the positive effects of good collaterals on revascularization by EVT are restricted to certain subgroups of patients.

Computational fluid dynamics modeling of symptomatic intracranial atherosclerosis may predict risk of stroke recurrence.

Background Patients with symptomatic intracranial atherosclerosis (ICAS) of ≥70% luminal stenosis are at high risk of stroke recurrence. We aimed to evaluate the relationships between hemodynamics of ICAS revealed by computational fluid dynamics (CFD) models and risk of stroke recurrence in this patient subset. Methods Patients with a symptomatic ICAS lesion of 70–99% luminal stenosis were screened and enrolled in this study. CFD models were reconstructed based on baseline computed tomographic angiography (CTA) source images, to reveal hemodynamics of the qualifying symptomatic ICAS lesions. Change of pressures across a lesion was represented by the ratio of post- and pre-stenotic pressures. Change of shear strain rates (SSR) across a lesion was represented by the ratio of SSRs at the stenotic throat and proximal normal vessel segment, similar for the change of flow velocities. Patients were followed up for 1 year. Results Overall, 32 patients (median age 65; 59.4% males) were recruited. The median pressure, SSR and velocity ratios for the ICAS lesions were 0.40 (−2.46–0.79), 4.5 (2.2–20.6), and 7.4 (5.2–12.5), respectively. SSR ratio (hazard ratio [HR] 1.027; 95% confidence interval [CI], 1.004–1.051; P = 0.023) and velocity ratio (HR 1.029; 95% CI, 1.002–1.056; P = 0.035) were significantly related to recurrent territorial ischemic stroke within 1 year by univariate Cox regression, respectively with the c-statistics of 0.776 (95% CI, 0.594–0.903; P = 0.014) and 0.776 (95% CI, 0.594–0.903; P = 0.002) in receiver operating characteristic analysis. Conclusions Hemodynamics of ICAS on CFD models reconstructed from routinely obtained CTA images may predict subsequent stroke recurrence in patients with a symptomatic ICAS lesion of 70–99% luminal stenosis.

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.

Combined Use of Mechanical Thrombectomy with Angioplasty and Stenting for Acute Basilar Occlusions with Underlying Severe Intracranial Vertebrobasilar Stenosis: Preliminary Experience from a Single Chinese Center

BACKGROUND AND PURPOSE: Acute basilar occlusions have a poor prognosis without recanalization. Many have underlying severe atherosclerotic intracranial stenosis coexisting with acute thrombosis, requiring treatment of both pathologies in the same session, though technical risks may be encountered. The purpose of this study was to evaluate the technical feasibility and safety of combined treatment by using stent retrievers for the thrombosis, together with angioplasty and stent placement for the underlying stenosis. MATERIALS AND METHODS: This was a retrospective review of 13 patients with basilar occlusions treated with thrombectomy by the Solitaire stent retriever and angioplasty and intracranial stent placement for underlying severe vertebrobasilar stenosis in the same session. Reperfusion was assessed in terms of the TICI score. Perioperative complications were recorded. Clinical outcomes were assessed by the NIHSS at discharge and the mRS on follow-up at 90 days. RESULTS: Of the 30 patients with acute basilar artery occlusions treated with stent retrievers during the study period, 18 had coexisting severe intracranial stenosis. Thirteen patients meeting the criteria for our study received combined mechanical thrombectomy and angioplasty with stent placement. The successful recanalization rate was 100%. Distal vessel embolizations occurred in 3 patients. There were 2 mortalities. On discharge, 10 patients (77%) had an improvement in NIHSS of ≥10 points. At 90 days, 6 patients (46%) had a good functional outcome with an mRS of ≤2. CONCLUSIONS: The combined use of mechanical thrombectomy with angioplasty and stent placement for acute basilar occlusions with underlying severe intracranial atherosclerotic stenosis is technically feasible and safe.

Thirty-Day Outcome of a Multicenter Registry Study of Stenting for Symptomatic Intracranial Artery Stenosis in China

Background and Purpose— Although recent trials have suggested that stenting is worse than medical therapy for patients with severe symptomatic intracranial atherosclerotic stenosis, it is not clear whether this conclusion applies to a subset of patients with hypoperfusion symptoms. To justify for a new trial in China, we performed a multicenter prospective registry study to evaluate the safety and efficacy of endovascular stenting within 30 days for patients with severe symptomatic intracranial atherosclerotic stenosis. Methods— Patients with symptomatic intracranial atherosclerotic stenosis caused by 70% to 99% stenosis combined with poor collaterals were enrolled. The patients were treated either with balloon-mounted stent or with balloon predilation plus self-expanding stent as determined by the operators following a guideline. The primary outcome within 30 days is stroke, transient ischemic attack, and death after stenting. The secondary outcome is successful revascularization. The baseline characteristics and outcomes of the 2 treatment groups were compared. Results— From September 2013 to January 2015, among 354 consecutive patients, 300 patients (aged 58.3±9.78 years) were recruited, including 159 patients treated with balloon-mounted stent and 141 patients with balloon plus self-expanding stent. The 30-day rate of stroke, transient ischemic attack, and death was 4.3%. Successful revascularization was 97.3%. Patients treated with balloon-mounted stent were older, less likely to have middle cerebral artery lesions, more likely to have vertebral artery lesions, more likely to have Mori A lesions, less likely to have Mori C lesions, and likely to have lower degree of residual stenosis than patients treated with balloon plus self-expanding stent. Conclusions— The short-term safety and efficacy of endovascular stenting for patients with severe symptomatic intracranial atherosclerotic stenosis in China is acceptable. Balloon-mounted stent may have lower degree of residual stenosis than self-expanding stent. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01968122.

Arterial Spin Labeling Magnetic Resonance Imaging Estimation of Antegrade and Collateral Flow in Unilateral Middle Cerebral Artery Stenosis

Background and Purpose— Three-dimensional pseudocontinuous arterial spin labeling with multiple postlabeling delays has been used to assess cerebral blood flow (CBF). We used this modality to estimate antegrade and collateral flow in patients with unilateral middle cerebral artery stenosis. Methods— Consecutive patients with unilateral middle cerebral artery 50% to 99% stenosis at 2 centers underwent pseudocontinuous arterial spin labeling with a postlabeling delays of 1.5 and 2.5 s. Mean CBF of bilateral middle cerebral artery territory at the postlabeling delays 1.5 and 2.5 s was measured. Early-arriving flow proportion was defined as (CBF 1.5 s at lesion side/CBF 2.5 s at normal side)×100%. Late-arriving retrograde flow proportion was defined as ([CBF 2.5 s−CBF 1.5 s] at lesion side−[CBF 2.5 s−CBF 1.5 s] at normal side)/CBF 2.5 s at normal side×100%. Antegrade and collateral scales were evaluated in patients with conventional angiography. Spearman correlation coefficients were calculated between early-arriving flow and late-arriving retrograde flow proportions on arterial spin labeling and antegrade and collateral scales on conventional angiography, respectively. Results— Forty-one patients (46.0±12.0 years) were enrolled. The mean early-arriving flow proportion was 78.3±14.9%. The mean late-arriving retrograde flow proportion was 16.1±10.2%. In 21 patients with conventional angiography, Spearman correlation coefficient was 0.53 (95% confidence interval, 0.11–0.79) between antegrade grade and early-arriving flow proportion (P=0.01) and 0.81 (95% confidence interval, 0.56–0.92) between collateral grade and late-arriving retrograde flow proportion (P<0.0001). Conclusions— Three-dimensional pseudocontinuous arterial spin labeling with 2 postlabeling delays may provide an empirical approach for estimating antegrade and collateral flow in patients with unilateral middle cerebral artery stenosis. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT02479243.

Endovascular Mechanical Thrombectomy with the Solitaire Device for the Treatment of Acute Basilar Artery Occlusion

OBJECTIVE To determine the safety and efficacy of endovascular treatment with the Solitaire device for acute basilar artery occlusion (ABAO) and identify factors affecting clinical outcomes. METHODS We enrolled 36 consecutive ABAO patients (aged 58.6 ± 8.10 years) who underwent mechanical thrombectomy with the Solitaire device. We analyzed baseline characteristics, mechanical thrombectomy results, and factors predicting clinical outcomes, which were assessed at 90 days. RESULTS The median prethrombectomy National Institutes of Health Stroke Scale (NIHSS) score was 25.50 (interquartile range: 21.00-29.00); the median prethrombectomy Glasgow Coma Scale (GCS) score was 8.00 (5.00-9.75). Thirty patients (83.3%) had atherosclerotic stenosis of the occluded artery, and 25 underwent angioplasty (69.4%). Recanalization was successful (Thrombolysis in Cerebral Infarction grade: 2b-3) in 34 patients (94.4%). Six symptomatic intracranial hemorrhages (16.67%) occurred. Favorable outcomes (modified Rankin scale [mRS] score: 0-2) were achieved in 27.8% patients (10/36). The overall mortality rate was 30.6% (11/36) at 90 days. On univariate analysis, low prethrombectomy GCS and high post-thrombectomy NIHSS scores were associated with poor outcomes (mRS score >2) and mortality. Prethrombectomy unconsciousness, onset-to-recanalization time > 10.5 hours, and severe stenosis were associated with poor outcomes. Age ≥ 60 years was associated with mortality. CONCLUSIONS Endovascular treatment with the Solitaire device yielded high recanalization rates in ABAO patients and favorable clinical outcomes in approximately one third of patients. Intracranial stenosis was the main cause of occlusion. Angioplasty was commonly performed during mechanical thrombectomy to improve recanalization and prognosis. Early recanalization and better prethrombectomy status predicted better outcomes.

Protocol for a prospective, multicentre registry study of stenting for symptomatic intracranial artery stenosis in China

Introduction The SAMMPRIS trial suggested that aggressive treatment was superior to endovascular stenting in patients with severe symptomatic intracranial atherosclerotic stenosis (ICAS) due to high complication rates in patients in the stenting group. Given that 12.2% patients failed aggressive medical therapy in the SAMMPRIS study, it is imperative to perform a multicentre prospective registry study of stenting for patients with ICAS in China. This study aims to evaluate the safety and efficacy of endovascular stenting for patients with symptomatic intracranial artery stenosis and poor collaterals in China and to identify the characteristics of the population that would benefit the most from endovascular stenting in Chinese patients. Methods and analysis This multicentre prospective registry study will involve 20 stroke centres in China, and plans to recruit 300 patients into the registry. Patients with ≥70% stenosis and symptomatic intracranial atherosclerotic disease caused by hypoperfusion combined with poor collaterals who met the inclusion criteria and exclusion criteria would be enrolled for this study. The primary outcome is the target vessel stroke event (including haemorrhagic or ischaemic stroke) or death within 30 days after stenting. The secondary outcomes include the successful recanalisation rate, the incidence of recurrent ischaemic stroke in the territory of the stented artery between 30 days and 1 year postoperatively, the restenosis rate and health-related quality of life. Ethics and dissemination The protocol is approved by the ethics committee at the coordinating centre and by the local institutional review board at each participating centre. Findings will be shared with participating hospitals, policymakers and the academic community to promote quality monitoring, quality improvement and the efficient allocation and use of cerebral catheterisation and intracranial artery stenting in China. Trial registration number http://www.clinicaltrials.gov (NCT01968122).