Reduced cerebrovascular reserve is associated with an increased risk of postoperative ischemic lesions during carotid artery stenting

Distal normal vessel diameter might be associated with silent brain infarcts after stenting for symptomatic carotid stenosis

BACKGROUND

Carotid artery stenting (CAS) has been the standard treatment for carotid stenosis because it is less invasive; however, the risk of periprocedural thromboembolism is high. We investigated the predictors for silent brain infarcts (SBIs), focusing on embolic protection in CAS.

METHODS

This study was single-center retrospective study, and we obtained baseline demographics and clinical, laboratory, and periprocedural variables of patients who underwent CAS. Also, methods used for embolic protection (no EPD, distal EPD, or proximal balloon guiding catheter) during CAS were obtained. Distal normal vessel diameter was defined as the diameter of cervical internal carotid artery where the artery wall becomes parallel. Diffusion-weighted imaging was performed before and after procedure to detect SBIs. The primary outcome was stented territory SBIs, and the secondary outcomes were any territories SBIs and stented territory SBIs in cases with EPD.

RESULTS

A total of 196 CAS procedures with mean age 69.1 ± 9.9 years were included. After CAS, stented territory SBIs occurred in 53 (27.0 %) cases and any territories SBIs in 60 (30.6 %) cases. Univariable analyses revealed that distal normal vessel diameter (odds ratio = 1.71, 95 % confidence interval = 1.20-2.43, P = 0.003) was associated with the occurrence of stented territory SBIs after CAS. After adjusting for potential variables, larger distal normal vessel diameter (1.61 [1.10-2.36], P = 0.014) increased the occurrence of SBIs after CAS. Consistent results were obtained when the outcome was any territories SBIs or stented territory SBIs in cases with EPD.

CONCLUSIONS

Distal normal vessel diameter was a predictor for the occurrence of SBI after CAS. The passable pore size of EPDs may vary depending on vessel diameter, and may impact the occurrence of SBIs.

Absence of the Anterior Communicating Artery on Selective MRA is Associated with New Ischemic Lesions on MRI after Carotid Revascularization

BACKGROUND AND PURPOSE

ICA-selective MRA using a pencil beam presaturation pulse can accurately visualize anterior communicating artery flow. We evaluated the impact of anterior communicating artery flow on the perioperative hemodynamic status and new ischemic lesions after carotid revascularization.

MATERIALS AND METHODS

Eighty-three patients with carotid artery stenosis were included. We assessed anterior communicating artery flow using ICA-selective MRA. The preoperative hemodynamic status was measured using SPECT. We also measured the change in regional cerebral oxygen saturation after temporary ICA occlusion. New ischemic lesions were evaluated by DWI on the day after treatment.

RESULTS

Anterior communicating artery flow was detected in 61 patients, but it was not detected in 22 patients. Preoperative cerebrovascular reactivity was significantly higher in patients with (versus without) anterior communicating artery flow with a mean peak systolic velocity of ≥200 cm/s (39.6% [SD, 23.8%] versus 25.2% [SD, 16.4%]; P = .030). The decrease in mean regional cerebral oxygen saturation was significantly greater in patients without (versus with) anterior communicating artery flow (8.5% [SD, 5.6%] versus 3.7% [SD, 3.8%]; P = .002). New ischemic lesions after the procedure were observed in 23 patients. The multivariate logistic regression analysis revealed that anterior communicating artery flow (OR, 0.07; 95% CI, 0.012-0.45; P = .005) was associated with new ischemic lesions.

CONCLUSIONS

The absence of anterior communicating artery flow influenced the perioperative hemodynamic status in patients with carotid stenosis and was associated with an increased incidence of new ischemic lesions after carotid revascularization.

Identifying 'fast progressors' likely to benefit from mechanical thrombectomy

OBJECTIVES

Although the effect of mechanical thrombectomy in large vessel occlusions has been clearly demonstrated, there are different opinions about the treatment of patients with low ASPECT scores. We conducted this research to explore the utility of mechanical thrombectomy for the fast progressor patients.

METHODS

We evaluated 394 patients with large vessel occlusion (LVO) who applied to our center between 2012 and 2020 retrospectively. Patients with posterior system stroke and who admitted 6 h after the onset of symptoms, were not included in the study. The remaining 256 patients were divided into two groups as computed tomography angiography source image Alberta stroke program early computer tomography score (CTA-SI ASPECT) ≤ 6 and > 6. Modified rankin scale (mRS) 0-2 defined as good clinical outcome. Thrombolysis in cerebral infarction (TICI) score 2c-3 was accepted as successful recanalization.

RESULTS

The mean age of the patients in the fast-progressive group (23.4%; n = 60) was 66.3 ± 11.6 years, whereas the mean age of the CTA-SI ASPECTS > 6 group (76.6%; n = 196) was 62.4 ± 12.8 years (p = 0.034) A statistically significant difference was found between the groups regarding 90-day mRS (p < 0.001). Whereas 61.7% of the patients with a CTA-SI ASPECTS > 6 had a 90-day mRS 0-2, this rate was 28.3% for patients with a CTA-SI ASPECTS ≤ 6.

CONCLUSION

According to our study, approximately 1/3 of patients with ASPECTS ≤ 6 benefit from mechanical thrombectomy. In this patient group, age emerged as a determinant of good clinical outcome.

Risk factors for new ischemic cerebral lesions after carotid artery stenting: A systematic review and meta-analysis

BACKGROUND

New ischemic cerebral lesions (NICL) are commonly occur after carotid artery stenting (CAS) with an incidence rate ranging from 18-58% and are detected by diffusion-weighted imaging-magnetic resonance imaging (DWI-MRI). Numerous studies have reported that NICL could increase the risk of future cerebrovascular events and cognitive impairment. This systematic review and meta-analysis aimed to identify risk factors for NICL after CAS.

METHODS

Relevant literature reporting risk factors for NICL after CAS were searched. Randomized controlled trials, case-control studies, or cohort studies were included in accordance with the pre-specified eligibility criteria. The risk of bias was assessed using the Cochrane Collaboration criteria and the quality of evidence was assessed with the corresponding scale. Data were analyzed using the RevMan V. 5.3 analysis software.

RESULTS

The final analyses included a total of 21 studies and 1907 participants, including 764 NICL-positives and 1143 NICL-negatives. Determinants for NICL-positivity were age (mean deviation (MD): 2.60; 95% confidence interval (CI): [1.53-3.68]), symptomatic carotid lesions (odds ratio (OR): 1.77; 95% CI: [1.39-2.25]) and smoking (OR: 0.74; 95% CI: [0.58-0.94]). For symptomatic patients, risk factors for NICL-positive included diabetes mellitus (OR: 1.76; 95% CI: [1.09-2.82]), but smoking (OR: 0.54; 95% CI: [0.31-0.93]) was a protective factor. Risk factors for centers with high NICL incidence were age (MD: 2.05; 95% CI: [0.93-3.17]) and symptomatic carotid lesions (OR: 1.77; 95% CI: [1.29-2.45]).

CONCLUSIONS

Older age and symptomatic carotid lesions are associated with an increased risk of post-CAS NICL whereas smoking is associated with a decreased risk. Risk factors for NICL in symptomatic patients is diabetes mellitus, while those for patients at centers with high incidence are age and symptomatic carotid lesions. Systematic review registration: CRD42019121129.

Analysis of postprocedural microembolic infarctions and global oxygen extraction fraction during balloon-protected carotid artery stenting: Preliminary study

Background:

Atherosclerotic carotid stenosis with impaired cerebral perfusion is a risk factor for cerebral ischemia. In major carotid stenoocclusive diseases, increased oxygen extraction fraction (OEF) is associated with ischemic stroke. Balloon-protected carotid artery stenting (CAS) is valuable for high-grade carotid stenosis. However, while balloon-protected CAS can effectively reduce the occurrence of ischemic complications by blocking carotid flow, cerebral hypoperfusion may result in simultaneous cerebral ischemia. We sought to evaluate whether increased OEF during balloon-protected CAS can predict postprocedural microembolic infarction (MI).

Methods:

Eighty-four patients who underwent balloon-protected CAS were enrolled. Initial, intraprocedural, and postprocedural OEFs were calculated from the cerebral arteriovenous oxygen differences obtained from blood sampled just before the temporary occlusion and reperfusion of the internal carotid artery during and after the procedure. MIs were evaluated by diffusion-weighted imaging (DWI). Patients were classified into two groups based on the presence or absence of new MIs, and the relationship between the OEF and postprocedural MIs was analyzed.

Results:

New DWI-positive lesions were found in 37 cases (44.0%). Age, signal intensity ratio (SIR) of carotid plaque on T1-weighted black blood magnetic resonance imaging, and intraprocedural OEF were significantly higher in the DWI-positive group. The high SIR and intraprocedural OEF were significantly associated with the development of postprocedural MIs in multivariate analysis. MIs were correlated with the increase in OEF.

Conclusion:

Increased intraprocedural OEF, obtained by blood sampling during balloon-protected CAS, could predict the incidence of postprocedural MIs. Patients with carotid stenosis could be hemodynamically compromised by carotid flow blockage during balloon-protected CAS.

Age and the risk of new ischemic lesions on diffusion weighted imaging after carotid artery stenting: A systematic review and meta-analysis

To perform a systematic review and meta-analysis to show the association between age and the risk of new ischemic lesions on diffusion-weighted magnetic resonance imaging (DWI) after carotid artery stenting in patients with carotid artery stenosis. We searched PubMed and EMBASE from their dates of inception to March 14, 2019 for eligible studies. Standardized mean difference (SMD) and pooled odds ratio (OR) with 95% confidence interval (CI) was used to evaluate the association between age and new DWI lesions. Sensitivity analysis was performed to detect the possible source of heterogeneity. Twenty-three studies enrolling 2127 patients were included. The incidence of new DWI lesions was 62% in older patients and 41% in younger patient (OR 2.44, 95%CI 1.57-3.79; p < 0.0001). The patients with new DWI lesions were older than those without (SMD 0.24, 95% CI 0.08-0.39; p = 0.003). The risk of new DWI lesions increased by 1.07 per added year (95%CI 1.04-1.11, p < 0.0001). The results remained stable in sensitivity analyses and after adjusting for publication bias. It was concluded that older age was at higher risk of new DWI lesions after stenting in patients with carotid artery stenosis.

Risk factors for new ischaemic cerebral lesions after carotid artery stenting: protocol for a systematic review and meta-analysis

INTRODUCTION

New ischaemic cerebral lesions (NICL) detected by diffusion-weighted imaging MRI are common after carotid artery stenting (CAS), with an occurrence rate ranging from 18% to 57%. Many studies reported occurrence of NICL could increase risk of future cerebrovascular events and cognitive impairment. However, controversies about determinants for occurrence of NICL after CAS exist among studies, and one risk factor embodied in an article may not be in another. Aim of this study is to introduce a protocol for a systematic review and meta-analysis to identify risk factors associated with occurrence of NICL after CAS.

METHODS AND ANALYSIS

All relevant literature referring to risk factors for occurrence of NICL after CAS will be searched on the major databases, such as PubMed, Embase, Web of Science and the Cochrane Library until 31 December 2018. Literature, which must be randomised controlled trials, case-control studies or cohort studies, will be included in accordance with the prespecified eligibility criteria. The risk of bias will be assessed using the Cochrane Collaboration criteria and the quality of evidence will be assessed with the corresponding scale. Data will be extracted with a form prepared before and analysed using RevMan V.5.3 analyses software. Heterogeneity will be assessed using I² statistic. Our systematic review will be performed according to the guidance from the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

ETHICS AND DISSEMINATION

There is no need for ethical approval because primary data will not be attained. The systematic review will be presented at international conferences and published in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42019121129.

DWI-pc-ASPECT score in basilar artery occlusion: is 6 points or less always indicative of a bad outcome?

BACKGROUND AND PURPOSE

The prognosis of patients with acute basilar arterial occlusion after endovascular reperfusion therapy with diffusion-weighted imaging - posterior circulation-Alberta Stroke Program Early Computed Tomography Score (DWI-pc-ASPECTS) of 6 or less remains unclear. We aimed to assess the characteristics and prognosis of endovascular reperfusion therapy in patients with acute basilar arterial occlusion and DWI-pc-ASPECTS of 6 or less.

METHODS

We analysed data collected from 1 January 2012 to 31 January 2018 in a prospective neuro-interventional registry of consecutive patients treated with endovascular reperfusion therapy. Clinical and imaging data on patients with DWI-pc-ASPECTS of 6 or less who underwent endovascular reperfusion therapy for acute basilar arterial occlusion were collected for this study. A good clinical outcome was defined as a modified Rankin scale of 2 or less at 90 days.

RESULTS

Forty-five acute basilar arterial occlusion patients with DWI-pc-ASPECTS of 6 or less were included. Among them, 11 (24.4%) patients had a good clinical outcome at 90 days. Patients with a good clinical outcome had less severe neurological symptoms at presentation (National Institutes of Health Stroke Scale (NIHSS) 19.0 (12.0-25.0) vs. 8.0 (6.0-11.5); P = 0.003) and were younger (72.5 years (57.0-80.0 years) vs. 63.0 years (55.5-69.0 years), P = 0.096) than those with a poor clinical outcome. The symptomatic intracranial haemorrhage rate was significantly higher in the poor clinical outcome group (13 (38.2%)) than in the good clinical outcome group (0 (0.0%)) (P = 0.045). In particular, in patients aged over 70 years, a favourable outcome was low (18 (52.9%) vs. 1 (9.1%); P = 0.027) even after successful recanalisation. In a multivariate model, a low initial NIHSS score (odds ratio 1.21; 95% confidence interval 1.07-1.44; P = 0.0093) and age over 70 years (odds ratio 15.27; 95% confidence interval 1.85-379.79; P = 0.0321) were independent predictors of poor clinical outcome.

CONCLUSIONS

Even with DWI-pc-ASPECTS of 6 or less, good clinical outcome can be achieved after endovascular reperfusion therapy. Relatively mild initial symptoms and younger age can predict a better outcome in acute basilar arterial occlusion patients with DWI-pc-ASPECTS of 6 or less.

Development of reserves over the life course and onset of vulnerability in later life

This Review develops a theoretical framework for the development and onset of vulnerability in later life based on the concept of reserves. We stress the advantages of using the concept of reserves in interdisciplinary life-course studies, compared with related concepts such as resources and capital. We enrich the definition of vulnerability as a lack of reserves and a reduced capacity of an individual to restore reserves. Two dimensions of reserves, originating from lifespan psychology and gerontology, are of particular importance: their constitution and sustainability by behaviours and interaction with the environment (the 'use it or lose it' paradigm) and the presence of thresholds, below which functioning becomes highly challenging. This heuristic approach reveals the potential for a conceptualization of reserves and is exemplified in an empirical illustration. Further interdisciplinary research based on the concept is needed.

Outcome of mechanical thrombectomy in the very elderly for the treatment of acute ischemic stroke: the real world experience

Background

Although initial studies of neuroendovascular intervention did not review benefit over intravenous thrombolytics (iv r-tPA), recent studies have suggested otherwise. Elderly patients (age ≥80 years) are typically excluded from clinical trials.

Purpose

To examine the utility of mechanical thrombectomy based on patient outcomes.

Material and Methods

All stroke-alert activations at our health system from January 2011 to June 2014 were examined. All patients aged ≥80 years who had undergone mechanical thrombectomy were identified. Clinical characteristics included physiologic imaging findings, use of intravenous thrombolytics, baseline and postoperative National Institute of Health Stroke Scale (NIHSS), thrombolysis in cerebral infarction scores (TICI), and discharge destination.

Results

Mean NIHSS on presentation was 18.2 (range, 6–31), and 13.3 (range, 3–30) post thrombectomy. Three (16.6%) patients received iv r-tPA, two (11.1%) had symptomatic intracranial hemorrhage. Eight (44.4%) died, eight (44.4%) were discharged to nursing homes, and two (11.7%) were discharged to inpatient rehab and subsequently home. Favorable outcome was achieved in five (27.7%) patients. Fourteen (77.7%) patients had physiologic imaging prior to intervention. Three (75%) of four patients who did not have physiologic imaging prior to thrombectomy died. Thirteen (66.6%) patients had TICI 3 recanalization.

Conclusion

Our study showed that although there remains a role of mechanical thrombectomy in the treatment of acute ischemic stroke in very elderly patients, it is associated with significant higher morbidity and mortality compared to younger patients, but should remain a very viable treatment option when quality of life is the most important consideration.

Cerebrovascular reserve may be a more accurate predictor of stroke than degree of ICA or MCA stenosis

Background

It is currently unclear whether the degree of stenosis or the cerebrovascular reserve (CVR) is a better predictor of ischemic stroke.

Material/Methods

In this study, CVR was measured by perfusion computed tomography with inhalation of 5% CO₂ in 37 symptomatic patients with internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis or occlusion. Patients were divided into groups according to the degree of stenosis: ≥70% stenosis (stenosis group 1) or <70% stenosis (stenosis group 2); and according to CVR: ≥10% CVR (CVR group 1) or <10% CVR (CVR group 2). All patients were given medical treatment.

Results

During a mean follow-up period of 56.9 months (range 24–73 months), recurrent ipsilateral ischemic stroke occurred in 7 patients. Ischemic stroke occurred in 0 of 19 patients in CVR group 1 (annual risk 0%), 7 of 18 patients in CVR group 2 (annual risk 7.7%), 3 of 18 patients in stenosis group 1 (annual risk 3.3%), and 4 of 19 patients in stenosis group 2 (annual risk 4.7%). Comparisons using Pearson’s chi-square test showed a significant difference in the rate of ischemic stroke between CVR group 1 and CVR group 2 (odds ratio 1.700; 95% confidence interval 1.142–2.530; P=0.003), but no significant difference between stenosis group 1 and stenosis group 2 (P=0.691).

Conclusions

Cerebrovascular reserve may be a more accurate predictor of stroke than degree of ICA or MCA stenosis.