Citations

Background Delayed neurological improvement (DNI) is a phenomenon that involves patient improvement in the absence of early neurological change following treatment for acute ischemic stroke. The patient characteristics associated with this condition are largely unexplored. Methods Following the PRISMA guidelines, a systematic review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. We calculated pooled odds ratios (ORs), mean differences (MDs), and their corresponding 95% confidence intervals (CIs) to test the association between patient characteristics and achievement of DNI. Results Seven studies, with 3266 patients, were included in our analysis. All studies reported a different definition of DNI, with five studies focusing on rates of good functional outcome at 90 days post-treatment in the absence of early neurological improvement. Use of intravenous thrombolytics was associated with increased rates of DNI (OR 1.96, 95% CI 1.28 to 3.00; p = 0.002). Atrial fibrillation was associated with decreased rates of DNI (OR 0.69, 95% CI 0.57 to 0.82; p < 0.001), as was hypertension (OR 0.66, 95% CI 0.53 to 0.83, p < 0.001), and diabetes mellitus (OR 0.71, 95% CI 0.56 to 0.90; p = 0.005). On average, patients who achieved DNI were 6.30 years younger than their non-DNI counterparts ( MD −6.30, 95% CI −9.19 to −3.41; p < 0.001). There were modest associations between male sex and DNI (OR 1.36, 95% CI 1.01 to 1.74, p = 0.042), and smoking and DNI (OR 1.28, 95% CI 1.03 to 1.59, p = 0.027). Conclusions DNI is a phenomenon that is not presently well understood. Lack of uniformity among definitions of DNI hinders efforts to explore DNI and the factors associated with its occurrence. Future studies should work to establish a consensus definition of DNI to determine its causes and significance more accurately.

Background Covert cerebrovascular disease (CCD) has been shown to be associated with dementia in population‐based studies with magnetic resonance imaging (MRI) screening, but dementia risk associated with incidentally discovered CCD is not known. Methods and Results Individuals aged ≥50 years enrolled in the Kaiser Permanente Southern California health system receiving head computed tomography (CT) or MRI for nonstroke indications from 2009 to 2019, without prior ischemic stroke/transient ischemic attack, dementia/Alzheimer disease, or visit reason/scan indication suggestive of cognitive decline or stroke were included. Natural language processing identified incidentally discovered covert brain infarction (id‐CBI) and white matter disease (id‐WMD) on the neuroimage report; white matter disease was characterized as mild, moderate, severe, or undetermined. We estimated risk of dementia associated with id‐CBI and id‐WMD. Among 241 050 qualified individuals, natural language processing identified 69 931 (29.0%) with id‐WMD and 11 328 (4.7%) with id‐CBI. Dementia incidence rates (per 1000 person‐years) were 23.5 (95% CI, 22.9–24.0) for patients with id‐WMD, 29.4 (95% CI, 27.9–31.0) with id‐CBI, and 6.0 (95% CI, 5.8–6.2) without id‐CCD. The association of id‐WMD with future dementia was stronger in younger (aged <70 years) versus older (aged ≥70 years) patients and for CT‐ versus MRI‐discovered lesions. For patients with versus without id‐WMD on CT, the adjusted HR was 2.87 (95% CI, 2.58–3.19) for younger and 1.87 (95% CI, 1.79–1.95) for older patients. For patients with versus without id‐WMD on MRI, the adjusted HR for dementia risk was 2.28 (95% CI, 1.99–2.62) for younger and 1.48 (95% CI, 1.32–1.66) for older patients. The adjusted HR for id‐CBI was 2.02 (95% CI, 1.70–2.41) for younger and 1.22 (95% CI, 1.15–1.30) for older patients for either modality. Dementia risk was strongly correlated with id‐WMD severity; adjusted HRs compared with patients who were negative for id‐WMD by MRI ranged from 1.41 (95% CI, 1.25–1.60) for those with mild disease on MRI to 4.11 (95% CI, 3.58–4.72) for those with severe disease on CT. Conclusions Incidentally discovered CCD is common and associated with a high risk of dementia, representing an opportunity for prevention. The association is strengthened when discovered at younger age, by increasing id‐WMD severity, and when id‐WMD is detected by CT scan rather than MRI.

OBJECTIVE Bioresorbable flow diverters (BRFDs) could significantly improve the performance of next-generation flow diverter technology. In the current work, magnesium and iron alloy BRFDs were prototyped and compared in terms of porosity/pore density, radial strength, flow diversion functionality, and resorption kinetics to offer insights into selecting the best available bioresorbable metal candidate for the BRFD application. METHODS BRFDs were constructed with braided wires made from alloys of magnesium (MgBRFD) or iron (FeBRFD). Pore density and crush resistance force were measured using established methods. BRFDs were deployed in silicone aneurysm models attached to flow loops to investigate flow diversion functionality and resorption kinetics in a simulated physiological environment. RESULTS The FeBRFD exhibited higher pore density (9.9 vs 4.3 pores/mm2) and crush resistance force (0.69 ± 0.05 vs 0.53 ± 0.05 N/cm, p = 0.0765, n = 3 per group) than the MgBRFD, although both crush resistances were within the range previously reported for FDA-approved flow diverters. The FeBRFD demonstrated greater flow diversion functionality than the MgBRFD, with significantly higher values of established flow diversion metrics (mean transit time 159.6 ± 11.9 vs 110.9 ± 1.6, p = 0.015; inverse washout slope 192.5 ± 9.0 vs 116.5 ± 1.5, p = 0.001; n = 3 per group; both metrics expressed as a percentage of the control condition). Last, the FeBRFD was able to maintain its braided structure for > 12 weeks, whereas the MgBRFD was almost completely resorbed after 5 weeks. CONCLUSIONS The results of this study demonstrated the ability to manufacture BRFDs with magnesium and iron alloys. The data suggest that the iron alloy is the superior material candidate for the BRFD application due to its higher mechanical strength and lower resorption rate relative to the magnesium alloy.

Background Previous randomized controlled trials (RCTs) and meta-analyses were underpowered to demonstrate the superiority of endovascular thrombectomy (EVT) over medical therapy (MEDT) in the treatment of acute ischemic stroke due to large vessel occlusion of the posterior circulation (PC-LVO). We performed an updated systematic review and meta-analysis after the publication of the BAOCHE and ATTENTION trials to determine whether EVT can benefit patients presenting with PC-LVO. Methods Using Nested Knowledge, we screened literature for RCTs on EVT in PC-LVO. The primary outcome was 90-day modified Rankin Scale (mRS) score 0–3, and secondary outcomes included 90-day mRS score 0–2, 90-day mortality, and rate of symptomatic intracranial hemorrhage (sICH). A random-effects model was used to compute rate ratios (RRs) and their corresponding 95% confidence intervals (CIs). Results Four RCTs with 988 patients, 556 patients in the EVT arm and 432 patients in the MEDT arm, were included in the meta-analysis. EVT resulted in significantly higher rates of mRS score 0–3 (RR=1.54; 95% CI 1.16 to 2.04; P=0.002) and functional independence (RR=1.83; 95% CI 1.08 to 3.08; P=0.024), and lower rates of mortality (RR=0.76; 95% CI 0.65 to 0.90; P=0.002) at 90-day follow-up compared with MEDT alone. However, EVT patients had higher rates of sICH (RR=7.48; 95% CI 2.27 to 24.61; P<0.001). Conclusions EVT conferred significant patient benefit over MEDT alone in the treatment of PC-LVO. Future studies should better define patients for whom EVT is futile and determine factors that contribute to higher rates of sICH.

Background: New trials are planned regularly to provide the highest quality of evidence and invade new occlusion territories, which requires a pre-defined reporting strategy with consistent, common data elements for more straightforward collective evidence synthesis. We sought to review all active endovascular thrombectomy trials to investigate their patient selection criteria, intervention description, and reported outcomes. Methods: A literature search was systematically conducted on clinicaltrials.gov for active trials and all intervention, inclusion criteria, and outcomes reported were extracted. A qualitative synthesis of the frequency of study design types and data elements are graphically and narratively presented. Results: A total of 32 studies were tagged and included in the final qualitative analysis. The inclusion criteria were highly variable, including different cut-offs for the last well-known baseline National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and modified Rankin scale (mRS). Half of the studies (16/32) mentioned “thrombectomy” without defining which technique or device was used, and the final thrombolysis in cerebral infarction scale was provided in 19 (59.4%) studies. Heterogeneity was also present among the studies reporting a first-pass effect, both in how studies defined the outcome and in used ranges for mRS. Mortality and intracerebral hemorrhage (ICH) were more homogenous in their presentation and follow-up. Conclusions: There is a great degree of heterogeneity in the active thrombectomy trials concerning inclusion criteria, interventions used, and how outcomes are being reported.

Neurovascular catheter technology has rapidly evolved over the past decade. While performance characteristics are well known to the practitioner, the design features of these new-generation catheters and their implications on performance metrics remain a mystery to most clinicians due to the limited number of available resources. This knowledge gap hampers informed device choices and also limits collaboration between clinicians and engineers. To aid fellow neurointerventionalists, in this primer we have summarized the basic concepts of catheter design and construction.

Background The Contour is a new generation intrasaccular flow disruption tool that aims to cover the aneurysm neck and is sized according to the neck diameter. While several case series have been published, no literature review has been performed on this promising device. Objective To assess the safety and effectiveness profile of the Contour Neurovascular System for wide-necked aneurysms. Methods We followed the recommendations of the PRISMA checklist Four databases were searched with a supplemental manual search. All data were analyzed using R software version 4.2.1. Results We finally included six studies with 131 treated aneurysms. The overall procedural time was 97.27 (95% CI = 70.07–124.47) minutes, ranging from 78.9 to 136.0 min. The pooled adequate occlusion rate was 84.21% (95% CI = 75.45–90.25), and the overall functional independence rate was 94.74% (87.97–97.79). The overall adverse event rate was 4.70 (95% CI = 3.24–6.76), varying among different events from 0.78 to 8.53%. Thromboembolic events were the most commonly encountered in 8.53% of the patients (95% CI = 4.78–14.74), followed by headache and minor stroke with incidence rates of 5.88 (95% CI = 2.83–11.83) and 4.35 (95% CI = 1.41–12.63), respectively. The overall procedural time in studies using the Contour system only was 86.17 (95% CI = 68.70–10.64) minutes, while it was 136 (95% CI = 90.96–181.04) in the Contour-assisted coiling procedures. However, both techniques were comparable regarding adequate occlusion rates and functional independence. Conclusion With the anticipation of future studies, the Contour Neurovascular System is a safe and effective treatment option for wide-necked intracranial aneurysms.

Background Early neurological deterioration (END) is a potential predictor for 90-day outcomes following mechanical thrombectomy for acute ischemic stroke (AIS). We performed a systematic review and meta-analysis to better understand whether END can be used as a surrogate for long-term outcomes. Methods Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, MEDLINE, and Embase. END definition was cataloged for each included study. Outcomes of interest included 90-day modified Rankin Scale (mRS) 0–2, symptomatic intracranial hemorrhage (sICH), mortality, and thrombolysis in cerebral infarction (TICI) 2b-3. We calculated pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI) for all definitions of END. Results We included seven studies with 2992 patients in our analysis. There was a significant, inverse association with END and mRS 0–2 rates (OR = 0.15; 95% CI = 0.08–0.29; P-value< 0.001). Moreover, END was a significant predictor of increased odds for reported sICH rates (OR = 16.37; 95% CI = 7.66–34.99; P-value< 0.001). Furthermore, there was a significant association between END and increase in mortality rates (OR = 6.79; 95% CI = 2.62–17.62; P-value< 0.001). There was no significant association between END and rates of TICI 2b-3 (OR = 0.53; 95% CI = 0.27–1.05; p = 0.069). Conclusions Broadly defined, END holds value as a potential predictor of rates of mRS 0–2 at 90 days and is associated with higher rates of mortality and sICH, but had no correlation with TICI 2b-3.

Background Wake-up stroke represents a significant challenge in acute treatment and care. Thrombolysis has been extensively studied in the wake-up stroke population. However, mechanical thrombectomy in wake-up stroke exclusively has not been well studied. We performed a systematic review and meta-analysis to assess the clinical and functional outcomes of patients undergoing mechanical thrombectomy for wake-up stroke. Methods We performed a systematic review of the literature using publically accessible databases. Data extraction was completed using Nested Knowledge AutoLit software. Outcomes of interest included modified Rankin Scale (mRS) 0–2, mortality, symptomatic intracerebral hemorrhage (sICH), and thrombolysis in cerebral infarction (TICI) score 2b/3. Statistical analysis was performed using R software version 4.1.2. Results A total of 12 studies were included in our study with a total of 510 patients included. Patients with wake-up stroke were found to have good functional outcome (mRS 0–2) in 46.2% of patients and successful reperfusion (TICI 2b/3) was seen in 83.5% of patients. Mortality was observed in 20.4% of patients with sICH seen in 8.3%. Conclusion Mechanical thrombectomy for patients with wake-up stroke was found to have favorable rates of good functional outcomes and relatively low rates of adverse events.