American Society Of Interventional And Therapeutic Neuroradiology/Society Of Interventional Radiology Research Articles

Hypoperfusion Intensity Ratio Correlates with Angiographic Collaterals and Infarct Growth in Acute Stroke with Thrombectomy.

The assessment of collaterals before endovascular thrombectomy (EVT) therapy play a pivotal role in clinical decision-making for acute stroke patients. To investigate the correlation between hypoperfusion intensity ratio (HIR), collaterals on digital subtraction angiography (DSA), and infarct growth in acute stroke patients who underwent EVT therapy. Patients with acute ischemic stroke (AIS) who underwent EVT therapy were enrolled retrospectively. HIR was assessed through magnetic resonance imaging (MRI) and was defined as the Tmax > 10 s lesion volume divided by the Tmax > 6 s lesion volume. Collaterals were assessed on DSA using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Good collaterals were defined as ASITN/SIR score 3-4 and poor collaterals were defined as ASITN/SIR score 0-2. Spearman's rank correlation analysis was used to evaluate the correlation between HIR, collaterals, infarct growth, and functional outcome. A total of 115 patients were included. Patients with good collateral (n = 59) had smaller HIR (0.29 ± 0.07 vs. 0.52 ± 0.14; t = 10.769, P < 0.001) and infarct growth (8.47 ± 2.40 vs. 14.37 ± 5.28; t = 7.652, P < 0.001) than those with poor collateral (n = 56). The ROC analyses showed that the optimal cut-off value of HIR was 0.40, and the sensitivity and specificity for predicting good collateral were 85.70% and 96.61%, respectively. With the optimal cut-off value, patients with HIR < 0.4 (n = 67) had smaller infarct growth (8.86 ± 2.59 vs. 14.81 ± 5.52; t = 6.944, P < 0.001) than those with HIR ≥ 0.4 (n = 48). Spearman's rank correlation analysis showed that HIR had a correlation with ASITN/SIR score (r = -0.761, P < 0.001), infarct growth (r = 0.567, P < 0.001), and mRS at 3 months (r = -0.627, P < 0.001). HIR < 0.4 is significantly correlated with good collateral status and small infarct growth. Evaluating HIR before treatment may be useful for guiding EVT and predicting the functional outcome of AIS patients.

Efficacy and safety of endovascular therapy after 24 h from ischemic stroke onset in patients with acute anterior circulation ischemic stroke

Objective: To explore the effectiveness and safety of endovascular treatment (EVT) for patients with acute anterior circulation ischemic stroke with symptom onset exceeding 24 h. Methods: In this retrospective cohort study, data were extracted from patients who underwent endovascular treatment for acute anterior circulation ischemic stroke at the First Hospital of Jilin University from February 2019 to April 2022. A total of 569 patients were included, with a mean age of 63 (54-70) years. Among them, 398 (69.9%) were male. The patients were divided into two groups based on symptom onset time:>24 h group and≤24 h group. Propensity score matching (PSM) was used to match the patients in a 1︰1 ratio between the>24 h group and the≤24 h group. Logistic regression was used to evaluate the impact of symptom onset time on outcome events. Results: Before PSM, compared with≤24 h group, the>24 h group had a younger age [56 (48, 64) vs. 64 (55, 70), Z=-3. 60, P<0.001]; lower proportion of prior atrial fibrillation [1.8% (1/57) vs. 21.1% (108/512), χ2=12.39, P<0.001]; lower proportion of wake-up stroke [7.0% (4/57) vs. 27.7% (142/512), χ2=11.54, P<0.001]; lower baseline NIHSS score [11.0 (7.5, 14.0) vs. 13.0 (10.0, 16.0), Z=-3.22, P<0.001]; and a higher American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology(ASITN/SIR) grading (P<0.001). After PSM, there were no significant differences in baseline characteristics between the two groups. There was no significant difference in the proportion of patients with a modified Rankin Scale (mRS) score≤2 at 90 days after surgery between the two groups (before matching: 42.0% vs. 40.4%, OR=0.745, 95%CI 0.407-1.362, P=0.339; after matching: 51.8% vs. 39.3%, OR=0.511, 95%CI 0.212-1.236, P=0.136). No significant differences were observed in the incidence of any safety outcomes between the>24 h group and the≤24 h group. Conclusion: For patients with acute anterior circulation ischemic stroke with symptom onset exceeding 24 h, EVT is feasible after strict radiological screening and has similar safety and effectiveness as for patients with symptom onset under 24 h.

Association of intravascular enhancement sign on 3D-T1W TSE with collateral status in middle cerebral artery occlusion stroke

ObjectiveThe significance of the intravascular enhancement sign (IVES) on high-resolution magnetic resonance vascular wall imaging (HR-VWI) remains unclear. This study aimed to investigate the correlation between the IVES and collateral assessment derived from digital subtraction angiography (DSA). MethodA total of 75 patients with occlusion of the first segment of the middle cerebral artery (MCA) who underwent HR-VWI and DSA examinations at our research institution between November 2016 and February 2023 were included. The number of vessels with IVES, IVES-Alberta Stroke Program Early Computed Tomography Score (ASPECTS), American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral grade, and DSA collateral blood flow grade were retrospectively evaluated. Correlations between these indicators were assessed using Spearman's correlation. ResultsInterrater agreement was good for the assessment of HR-VWI and DSA indicators. After adjustments for age, degree of wall enhancement, and hypertension, a multivariable ordinal logistic regression model identified both the number of IVES vessels (OR = 1.37; 95%CI [1.06–1.78]; P = 0.017) and IVES-ASPECTS (OR = 2.00; 95%CI [1.03–3.87]; P = 0.041) as independent predictors of ischemic stroke. In the patient group with acute ischemic stroke, we found weak correlations between the number of IVES vessels and the ASITN/SIR collateral grade (rho = −0.35; P = 0.002) and between the IVES-ASPECTS and ASITN/SIR collateral grade (rho = −0.27; P = 0.02). Moreover, there were strong correlations between the number of IVES vessels and the DSA collateral blood flow grade (rho = −0.74; P < 0.001) and between the IVES-ASPECTS and the DSA collateral blood flow grade (rho = −0.65; P < 0.001). The number of IVES vessels correlated strongly with the IVES-ASPECTS (rho = 0.92, P < 0.001). ConclusionWe find that the IVES is closely associated with sluggish collateral blood flow, which further confirms the hemodynamic mechanism underlying the IVES in MCA occlusion.

The impact of collateral status on cerebral vasospasm and delayed cerebral ischemia in subarachnoid hemorrhage.

Cerebral collateral circulation may affect subarachnoid hemorrhage (SAH) induced cerebral vasospasm and delayed cerebral ischemia. In this study our aim was to investigate the relationship between collateral status, vasospasm and delayed cerebral ischemia (DCI) in both aneurysmal and nonaneurysmal SAH. Patients diagnosed as SAH with and without aneurysm were included and their data investigated retrospectively. After the patients diagnosed as SAH according to cerebral computed tomography (CT)/magnetic resonance imaging (MRI), they underwent cerebral angiography to check for cerebral aneurysm. The diagnosis of DCI was made according to the neurological examination and control CT/MRI. All the patients had their control cerebral angiography on days 7 to 10 in order to assess vasospasm and also collateral circulation. The American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) Collateral Flow Grading System was modified to measure collateral circulation. A total of 59 patients data were analyzed. Patients with aneurysmal SAH had higher Fisher scores and DCI was more common. Although there was no statistically significant difference between the patients with and without DCI in terms of demographics and mortality, patients with DCI had worse collateral circulation and more severe vasospasm. These patients had higher Fisher scores and more cerebral aneurysm overall. According to our data, patients with higher Fisher scores, more severe vasospasm, and poor cerebral collateral circulation may experience DCI more frequently. Additionally aneurysmal SAH had higher Fisher scores and DCI was seen more common. To improve the clinical results for SAH patients, we believe that physicians should be aware of the DCI risk factors.

Angiographic collateral venous phase: a novel landmark for leptomeningeal collaterals evaluation in acute ischemic stroke

BackgroundAlthough recanalization rates constantly increase (>80%), a favorable clinical outcome is achieved in only 45–55% of patients undergoing mechanical thrombectomy (MT) for anterior circulation stroke. Collateral circulation seems to play...

Correlation of Collateral Scores Derived from Whole-Brain Time-Resolved Flat Panel Detector Imaging in Acute Ischemic Stroke.

Flat panel detector CT imaging allows simultaneous acquisition of multiphase flat panel CTA and flat panel CTP imaging directly in the angio suite. We compared collateral assessment derived from multiphase flat panel CTA and flat panel CTP with collateral assessment derived from DSA as the gold-standard. We performed a retrospective analysis of patients with occlusion of the first or second segment of the MCA who underwent pre-interventional flat panel detector CT. The hypoperfusion intensity ratio as a correlate of collateral status was calculated from flat panel CTP (time-to-maximum > 10 seconds volume/time-to-maximum > 6 seconds volume). Intraclass correlation coefficients were calculated for interrater reliability for the Calgary/Menon score for multiphase flat panel CTA and for the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score for DSA collateral scores. Correlations of the hypoperfusion intensity ratio, multiphase flat panel CTA score, and the ASITN/SIR score were calculated using the Spearman correlation. From November 2019 to February 2020, thirty patients were included. Moderate interrater reliability was achieved for the ASITN/SIR DSA score (0.68; 95% CI, 0.50-0.82) as well as for the Calgary/Menon multiphase flat panel CTA score (0.53; 95% CI, 0.29-0.72). We found a strong correlation between the ASITN/SIR DSA and Calgary/Menon multiphase flat panel CTA score (ρ = 0.54, P = .002) and between the hypoperfusion intensity ratio and the Calgary/Menon multiphase flat panel CTA score (ρ = -0.57, P < .001). The correlation was moderate between the hypoperfusion intensity ratio and the ASITN/SIR DSA score (ρ = -0.49, P = .006). The infarct core volume correlated strongly with the Calgary/Menon multiphase flat panel CTA score (ρ = -0.66, P < .001) and the hypoperfusion intensity ratio (ρ = 0.76, P < .001) and correlated moderately with the ASITN/SIR DSA score (ρ = -0.46, P = .01). The Calgary/Menon multiphase flat panel CTA score and the hypoperfusion intensity ratio correlated with each other and with the ASITN/SIR DSA score as the gold-standard. In our cohort, the collateral scoring derived from flat panel detector CT was clinically reliable.

The value of whole-brain CT perfusion imaging combined with dynamic CT angiography in the evaluation of pial collateral circulation with middle cerebral artery occlusion.

Middle cerebral artery (MCA) occlusion is extremely common, especially unilateral artery, which can result in a significant incidence of cerebral infarction. To assess the value of whole-brain computed tomography perfusion (CTP) imaging combined with dynamic CT angiography (dCTA) in the evaluation of pial collateral circulation in patients with MCA occlusion. Whole-brain CTP and dCTA images were acquired in 58 patients with unilateral MCA occlusion. All patients were divided into three groups according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral score (by CTA). The CTP parameters were analysed, including relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative time to peak (rTTP). Patients were followed up with the modified Rankin scale (mRS). All cases in this study were confirmed by DSA. The CTP parameters of the MCA blood supply area on the affected side of patients with different degrees of stenosis were significantly different from those on the unaffected side. There are significant differences in the CTP parameters and openings of the Willis circle in patients with different degrees of stenosis. Significant differences were found in the number of patients with good prognosis. Whole-brain CT perfusion combined with dynamic CTA can structurally and functionally evaluate the establishment of pial collateral circulation and its effect on cerebral hemodynamic changes.

Does the Brush-Sign Reflect Collateral Status and DWI-ASPECTS in Large Vessel Occlusion?

IntroductionThe relevance of the brush-sign remained poorly documented in large vessel occlusion (LVO). We aimed to assess the relationship between the brush-sign and collateral status and its potential impact on baseline diffusion-weighted imaging–Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) in acute ischemic stroke (AIS) patients eligible to mechanical thrombectomy (MT).MethodsConsecutive patients admitted in the Lyon Stroke Center with anterior circulation AIS due to intracranial internal carotid artery (ICA) and/or M1 or M2 segment of the middle cerebral artery (MCA) occlusion eligible for MT were included. The brush-sign was assessed on T2-gradient-echo MRI. Collateral status was assessed on digital subtraction angiography according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score.ResultsIn this study, 504 patients were included, among which 171 (33.9%) patients had a brush-sign. Patients with a brush-sign more frequently had a poor collateral status [72 (42.1%) vs. 103 (30.9%); p = 0.017]. In univariable analysis, a DWI-ASPECTS < 7 was associated with a brush sign. Following multivariable analysis, the brush-sign no longer affected DWI-ASPECTS < 7 while the latter remained associated with younger age [odds ratio (OR) 0.97, 95% CI.96–0.99], male sex (OR 1.79, 95% CI 1.08–2.99), a higher National Institutes of Health Stroke Scale (NIHSS) score (OR 1.16, 95% CI 1.1–1.21), a poor collateral status (OR 9.35, 95% CI 5.59-16.02), MCA segment (OR 2.54, 95% CI 1.25–5.38), and intracranial ICA (OR 3.01, 95% CI 1.16–8) occlusion.Conclusions and RelevanceThe brush-sign may be a marker of poor collateral status but did not independently predict a lower DWI-ASPECTS.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT04620642.

Association of BIRC5 Gene Polymorphism with the Collateral Circulation and Severity of Large Artery Atherosclerotic Stroke.

Objectives The collateral circulation near the cerebral artery occlusion can contribute to the relief of the symptoms and signs of stroke. Genetic factors play a decisive role in the difference in collateral circulation. Survivin, encoded by the baculoviral inhibitor of apoptosis (IAP) repeat-containing 5 gene (BIRC5), plays an important role in maintaining long-term endothelial integrity and homeostasis and as an angiogenic factor in the treatment of vascular diseases. We hypothesized that genetic variations in the BIRC5 gene may contribute to severity by influencing the collateral circulation. This study aimed at examining how the polymorphism of the BIRC5 gene correlated with the collateral circulation and severity of large artery atherosclerotic stroke. Methods This study enrolled 428 patients with large artery atherosclerotic stroke. There are no statistical differences in age, sex, social behavior, such as smoking and drinking, between the groups classified by the collateral circulation and by the severity of stroke (P > 0.01). Direct sequencing was performed for the genotyping of single nucleotide polymorphism (SNP) of BIRC5 (rs2071214). The enrolled patients were divided into several subgroups based on the collateral flow grading system from the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR), the results of the National Institutes of Health Stroke Survey (NIHSS) (6 as a threshold), and the score of the modified Rankin scale (mRS) (for the prediction of prognosis, 2 as a threshold). Differences among subgroups were identified through logistic regression. Results The analysis of collateral circulation revealed the significant correlation of SNP of rs2071214 with the development of poor collateral circulation of large artery atherosclerotic stroke in the additive model (GG vs. AA, odds ratio (OR) = 3.592, 95% confidence interval (CI) = 1.410–9.150, and P=0.007) and the recessive model (GG vs. AA/GA, OR = 3.313, 95% CI = 1.420–7.727, and P=0.006). The analysis of stroke severity exposed the significant role of the SNP of rs2071214 in increasing stroke severity in the dominant model (GA/GG vs. AA, OR = 1.658, 95% CI = 1.017–2.703, and P=0.043) and the additive model (GA vs. AA, OR = 1.717, 95% CI = 1.021–2.888, and P=0.042). However, the analysis of the short-term outcome indicated that three genetic models were not associated with short-term outcomes in the additive model (GA vs. AA, P=0.815, GG vs. AA, and P=0.336), the dominant model (GA/GG vs. AA and P=0.589), and the recessive model (GG vs. AA/GA and P=0.342). Conclusion Our findings identified the SNP of rs2071214 of the BIRC5 gene as a risk factor for the poor compensatory ability of collateral circulation and a predictor of stroke severity in large artery atherosclerotic stroke, which suggested that the SNP of rs2071214 can serve as an innovative therapeutic target for patients with acute ischemic stroke.

Collateral status reperfusion and outcomes after endovascular therapy: insight from the Endovascular Treatment in Ischemic Stroke (ETIS) Registry

BackgroundStudies have suggested that collateral status modifies the effect of successful reperfusion on functional outcome after endovascular therapy (EVT). We aimed to assess the association between collateral status and EVT...

Susceptibility-diffusion mismatch correlated with leptomeningeal collateralization in large vessel occlusion stroke.

ObjectiveTo investigate the relationship between asymmetric prominent hypointense vessels (prominent vessel sign, PVS) on susceptibility-weighted imaging (SWI) and leptomeningeal collateralization in patients with acute ischemic stroke due to large vessel occlusion.MethodsWe retrospectively enrolled patients with M1 segment occlusion of the middle cerebral artery who underwent emergency magnetic resonance imaging and digital subtraction angiography within 24 hours from stroke onset. The extent of PVS on SWI was assessed using the Alberta Stroke Program Early CT Score (ASPECTS). Leptomeningeal collateralization on digital subtraction angiography images was assessed using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Spearman’s rank correlation test was performed to explore the correlation of ASITN/SIR scores with SWI-ASPECTS and SWI-diffusion-weighted imaging (DWI) mismatch scores.ResultsThirty-five patients were enrolled. There was no significant correlation between SWI-ASPECTS and ASITN/SIR scores. However, SWI-DWI mismatch scores were positively correlated with ASITN/SIR scores.ConclusionThe range of PVS on SWI did not closely reflect the collateral status, while the range of SWI-DWI mismatch was significantly correlated with the leptomeningeal collateralization. In patients with acute anterior circulation stroke due to large vessel occlusion, larger SWI-DWI mismatch was associated with better leptomeningeal collaterals.

Clinical significance of evaluation of collateral circulation in short-term prognosis of wake-up stroke patients.

In recent years, the clinical significance of collateral circulation in vascular embolism has been gradually found. To investigate the relationship between collateral circulation and short-term prognosis of wake-up stroke patients. The present observational study enrolled 269 cases of wake-up ischemic stroke patients. All patients presented with mismatched low perfusion volume/main infraction volume and received thrombolytic therapy after admission. The hemorrhagic transformation rate was recorded. The American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading was used for evaluation of collateral circulation. The stroke condition was determined using the National Institutes of Health Stroke Scale (NIHSS). The Barthel Index (BI) score was used for measurement of quality of life. The Modified Rankin Scale (mRS) was used for measurement of prognosis. The hypertension, diabetes and current smoker rates were significantly higher. The baseline NHISS scores and NIHSS scores after 24 h were remarkably lower. The NIHSS scores were markedly lower in ASITN/SIR grade 2-3 patients compared with ASITN/SIR grade 0-1 patients at 1 week, 2 weeks, 4 weeks, and 3 months after treatment. Patients with ASITN/SIR grade 2-3 had lower mRS score and higher BI scores. The ASITN/SIR grade was an independent risk factor for bad prognosis of wake-up ischemic stroke patients in 3 months. Collateral circulation condition may be associated with short-term prognosis of wake-up stroke patients. Patients with worse collateral circulation may present higher risk for bad short-term prognosis.

Cerebral autoregulation is heterogeneous in different stroke mechanism of ischemic stroke caused by intracranial atherosclerotic stenosis

Background and PurposeIntracranial atherosclerotic stenosis (ICAS) is the most common cause of ischemic stroke (IS) and is associated with stroke recurrence. It results in IS due to a variety of mechanisms. However, the influence of brain reserve mechanism on different stroke mechanism is still unclear. Cerebral autoregulation (CA) is an important brain reserve mechanism and is impaired after IS. This study aimed to explore the impaired pattern of CA and assess the association between CA and stroke risk factors in different stroke mechanism caused by ICAS.MethodsIS patients with ICAS (50%–99% stenosis/occlusion) in middle cerebral artery (MCA) or internal carotid artery were enrolled to receive CA examinations within 7 days after onset. Healthy volunteers were also recruited as controls. CA was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity. Transfer function analysis was used to derive CA parameters, including phase difference (PD) and coherence in the low‐frequency range (0.06–0.12 Hz).ResultsA total of 89 IS patients and 90 healthy controls were included. Compared with controls, CA was impaired ipsilaterally in patients with parent artery atherosclerosis occluding penetrating artery (POPA) while CA was bilaterally impaired in other stroke mechanisms. And CA on ipsilateral hemisphere was correlated with hypertension/hyperlipidemia in patients with POPA (r = −0.481, p = .008; r = −0.484, p = .008). While CA on ipsilateral hemisphere was correlated with perfusion parameter including the arterial spin‐labeling (ASL) parameter cerebral blood flow (CBF) (r = 0.893, p = .007) and collateral circulation status the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) (r = 0.610, p = .021) in patients with hypoperfusion mechanism.ConclusionIn IS patients, CA was impaired heterogeneously and was correlated with different risk factors in varied stroke mechanism. CA can be as an informative determinant of stroke risk in patients with ICAS and to help improving individualized treatment strategies in the presence of ischemic stroke caused by ICAS.

Hypoperfusion intensity ratio correlates with angiographic collaterals in acute ischaemic stroke with M1 occlusion

Among patients with an acute ischaemic stroke secondary to large-vessel occlusion, the hypoperfusion intensity ratio (HIR) [time to maximum (TMax)>10volume/TMax>6volume] is a strong predictor of infarct growth. We studied the correlation between HIR and collaterals assessed with digital subtraction angiography (DSA) before thrombectomy. Between January 2014 and March 2018, consecutive patients with an acute ischaemic stroke and an M1 middle cerebral artery (MCA) occlusion who underwent perfusion imaging and endovascular treatment at our center were screened. Ischaemic core (mL), HIR and perfusion mismatch (TMax>6s minus core volume) were assessed through magnetic resonance imaging or computed tomography perfusion. Collaterals were assessed on pre-intervention DSA using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Baseline clinical and perfusion characteristics were compared between patients with good (ASITN/SIR score 3-4) and those with poor (ASITN/SIR score 0-2) DSA collaterals. Correlation between HIR and ASITN/SIR scores was evaluated using Pearson's correlation. Receiver operating characteristic analysis was performed to determine the optimal HIR threshold for the prediction of good DSA collaterals. A total of 98 patients were included; 49% (48/98) had good DSA collaterals and these patients had significantly smaller hypoperfusion volumes (TMax>6s, 89 vs. 125mL; P=0.007) and perfusion mismatch volumes (72 vs. 89mL; P=0.016). HIR was significantly correlated with DSA collaterals (-0.327; 95% confidence interval, -0.494 to -0.138; P=0.01). An HIR cut-off of <0.4 best predicted good DSA collaterals with an odds ratio of 4.3 (95% confidence interval, 1.8-10.1) (sensitivity, 0.792; specificity, 0.560; area under curve, 0.708). The HIR is a robust indicator of angiographic collaterals and might be used as a surrogate of collateral assessment in patients undergoing magnetic resonance imaging. HIR <0.4 best predicted good DSA collaterals.

Predictors of risk of intracerebral hemorrhage after intracranial artery intervention in intracranial atherosclerotic stenosis patients

To investigate the relationship between clinical characters of intracranial atherosclerotic stenosis patients and occurrence of cerebral hemorrhage after intracranial artery intervention. Clinical data of total 501 patients who underwent endovascular therapy for ischemic stroke or transient ischemic attack were retrospectively reviewed. Median (interquartile range, IQR) of the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral score was higher in intracerebral hemorrhage (ICH) group (P < 0.001). Cerebral blood flow (CBF) reducing, cerebral blood volume (CBV) reducing, time to peak (TTP) delaying and mean transit time (MTT) delaying in the lesion side comparing the contralateral side were higher in ICH group (P = 0.018, P = 0.046, P = 0.012, P = 0.038). ASITN/SIR ≤ 2, CBF reducing ≥ 40%, CBV reducing ≥ 30%, TTP delaying ≥ 2 s, MTT delaying ≥ 1 s, infarction volume ≥ 20 mL were probably the independent predictors of ICH following endovascular therapy.

Inter- and intraobserver reliability for angiographic leptomeningeal collateral flow assessment by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale

BackgroundThe adequacy of leptomeningeal collateral flow has a pivotal role in determining clinical outcome in acute ischemic stroke. The American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR)...

Blood pressure and collateral circulation in acute ischemic stroke

This study aimed to evaluate the effect of different blood pressure (BP) parameters on the collateral circulation in aretrospective cohort of patients with acute ischemic stroke and ipsilateral internal carotid artery (ICA) occlusion. The degree of intracranial collaterals was graded according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) Collateral Flow Grading System. At 12-72 h after stroke onset, six BP measurements were obtained in 124 patients with ICA occlusion. Baseline clinical and imaging characteristics were collected. Group comparisons were performed, and the collateral score (CS) was assessed and entered into alogistic regression analysis. In all, 80 (64.5%) patients displayed good collateral filling (CS ≥ 2). Good intracranial collaterals were more frequently associated with the development of collaterals in the anterior communicating artery, posterior communicating artery, and leptomeningeal artery. The systolic blood pressure (SBP; p = 0.018), diastolic blood pressure (DBP; p = 0.013), and mean arterial pressure (MAP; p = 0.016) were significantly associated with good CS. Median CS was highest when SBP was 120-130 mm Hg (p = 0.034). Logistic regression analysis showed that hypertension (p = 0.026, OR: 0.380, 95% CI: 0.163-0.890) was asignificant predictor of poor CS. The development of collateral circulation in patients with acute ischemic stroke with ICA occlusion may be influenced by BP. Amoderately decreased SBP is associated with good integrity of the collateral circulation in patients with acute ischemic stroke with occlusion of the ICA.

Anterior Borderzone Angle for Hemodynamic Collateral Metric in Patients with Symptomatic Middle Cerebral Artery Stenosis

Background and Aims: We aimed to introduce a parameter of anterior borderzone angle (ABZA) to quantitatively evaluate the ACA-MCA leptomeningeal collaterals for middle cerebral artery stenosis (MCAS). Methods: Two hundred seventy-five patients with 50–100% MCAS and 100 controls were included. The 95% reference range of ABZA was obtained from the controls. ABZA_trans was defined as “ABZA/the 95% upper limit.” Relationships between ABZA and MCAS, ­ABZA_trans and the TICI grade, the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral grade were analyzed. An ABZA grade model for the ACA leptomeningeal collaterals was tentatively developed. Results: The 95% reference range of ABZA was 0.0º–23.0º. ABZA was significantly associated with MCAS by a function of the fourth power (R² = 0.723, p < 0.001), and could predict hemodynamic MCAS (≥70%) with an AUC of 0.928 (95% CI 0.903–0.953). ABZA_trans was negatively correlated with the TICI grade (rho = –0.752, p < 0.001) and positively with the ASITN/SIR grade (rho = 0.921, p < 0.001). The ABZA grade was created by rounding ­ABZA_trans to a nearest integer, and was closely associated with the ASITN/SIR grade (rho = 0.894, p < 0.001). Conclusions: ABZA can be used as a hemodynamic parameter to quantitatively evaluate ACA leptomeningeal collaterals.

A single-center study on endovascular thrombectomy for acute ischemic stroke

Objective To evaluate the efficiency and safety of endovascular thrombectomy for acute ischemic stroke caused by acute large vessel occulsion. Methods A total of 41 patients with acute ischemic stroke caused by acute large vessel occulsion were treated with endovascular thrombectomy. Time from onset to admission, from admission to femoral artery puncture, from onset to recanalization were recorded. Modified Thrombolysis in Cerebral Infarction (mTICI) was used to assess the recanalization immediately after operation. National Institutes of Health Stroke Scale (NIHSS) was used to evaluate the neurological function at 24 h after operation. Modified Rankin Scale (mRS) was used to evaluate clinical prognosis at 90 d after operation. Perioperative procedure-related complications and occurrence rate of symptomatic intracranial hemorrhage within at 90 d after operation were recorded. American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) Collateral Flow Grading System (ACG) was used to assess collateral compensation of anterior circulation. BATMAN score was used to assess collateral compensation of posterior circulation. Results Among 41 patients, 12 (29.27%) were treated with recombinant tissue-type plasminogen activator (rt-PA) intravenous thrombolysis. There were 32 patients (78.05%) achieved successful recanalization, including 20 patients (80%, 20/25) in anterior circulation and 12 (12/16) in posterior circulation, and no significant difference was seen between them (adjusted χ 2 = 1.424, P = 0.706). At 24 h after operation, 28 patients (68.29%) had better neurological function than preoperation (NIHSS decreasing ≥ 4 score), including 18 patients (72%, 18/25) with anterior circulation occlusion and 10 (10/16) with posterior circulation occlusion, and there was no significant difference between them (χ 2 = 0.407, P = 0.524). Eleven patients (26.83%) died within 90 d after operation, including 4 patients (16%, 4/25) with anterior circulation occlusion and 7 (7/16) with posterior circulation occlusion, and there was no significant difference between them (adjusted χ 2 = 2.130, P = 0.144). Among the 11 dead, 3 died of complicated pulmonary infection and respiratory failure, and 8 died of ischemic stroke. The other 30 patients were followed up for 3 months to one year, average (231.92 ± 95.36) d. At 90 d after operation, 14 patients (34.15%) had good outcome (mRS ≤ 2 score), including 10 patients (47.62%, 10/21) with anterior circulation occlusion and 4 (4/9) with posterior circulation occlusion, and there was no significant difference between them (adjusted χ 2 = 0.493, P = 0.483). Among 41 patients, 6 patients (14.63% ) had symptomatic intracranial hemorrhage, including 4 patients (16% , 4/25) with anterior circulation occlusion and 2 (2/16) with posterior circulation occlusion, and no significant difference was seen between them (adjusted χ 2 = 3.303, P = 0.856). Collateral compensation was evaluated in 33 patients (20 with anterior circulation occlusion and 13 with posterior patients circulation occlusion). In 20 patients with anterior circulation occlusion, 14 patients (70%) had good collateral compensation, in whom 9 (9/14) had good outcome 90 d after operation, while the other 6 patients (30%) had poor collateral compensation and then had good outcome 90 d after operation, and significant difference was seen between them (Fisher exact probability: P = 0.014). Among 13 patients with posterior circulation occlusion, 3 patients (3/13) had good collateral compensation and had good outcome 90 d after operation, while the other 10 (10/13) had poor collateral compensation, in whom one (1/10) had good outcome 90 d after operation, and significant difference was seen between them (Fisher exact probability: P = 0.014). Conclusions Endovascular thrombectomy is an efficient and safe method for acute ischemic stroke caused by acute large vessel occlusion. Rigorously master the indication and preoperative evaluation, and perfect acute rescue procedure and treatment for stroke may increase the efficacy of endovascular thrombectomy. DOI: 10.3969/j.issn.1672-6731.2017.11.005

Angiographic Correlates of Cerebral Hemodynamic Changes With Diamox Challenge Assessed by Quantitative Magnetic Resonance Angiography.

Impaired cerebrovascular reserve in chronic steno-occlusive disease has been shown to be associated with poor leptomeningeal collaterals (LMCs) on digital subtraction angiography and increased stroke risk. We examined the relationship between the degree of LMCs and the flow change with Diamox challenge measured using quantitative magnetic resonance angiography (QMRA). Patients with steno-occlusion in the internal carotid artery or middle cerebral artery (MCA) at our institution between 2007 and 2013 were retrospectively studied. Intracranial flows were obtained using QMRA, and flow change with Diamox (QMRAΔd) was calculated as follows: ([flow after Diamox-flow before Diamox]/[flow before Diamox])×100%. Poor LMC was defined as grade 1 or 2, and robust LMC was defined as grade 3 or 4 based on the ASITN/SIR (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology) grading system on digital subtraction angiography. Thirty-eight patients had angiographic and flow data. Ipsilateral MCA QMRAΔd was significantly lower versus the contralateral side (flow, 85.5 versus 135.9 mL/min; P<0.001 and QMRAΔd, 24.0% versus 45.6%; P=0.01). If LMCs were robust (n=12), MCA QMRAΔd was significantly higher (21.4% versus -26.8%; P=0.04) compared with patients with poor LMC (n=4). We show that patients with more robust LMC have better MCA QMRAΔd. Therefore, QMRAΔd may be used for the functional assessment of LMC as a surrogate for cerebrovascular reserve in chronic internal carotid artery or MCA steno-occlusive disease.