Seymour, Trey

Background Mechanical thrombectomy (MT) is a well-established treatment for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, its role in cervical artery dissection-related (CeAD) LVO remains debated due to anatomical complexities and procedural challenges. This systematic review and meta-analysis aims to evaluate the safety, efficacy, and clinical outcomes of MT in patients with AIS due to CeAD-related LVO compared with other AIS etiologies. Methods PubMed, Embase, and Scopus were systematically searched from inception to March 2025. Comparative observational studies evaluating the use of MT in adult patients with AIS due to LVO were included, specifically those comparing outcomes in patients with CeAD versus non-CeAD etiologies. Results MT for CeAD-related AIS showed no statistically significant difference in successful recanalization compared with non-CeAD cases (OR 0.81 (95% CI 0.63 to 1.04), P=0.10). However, patients with CeAD-related AIS had significantly higher rates of 90-day functional independence (modified Rankin Scale score 0–2) (OR 2.17 (95% CI 1.55 to 3.05), P<0.01) and lower 90-day mortality (OR 0.34 (95% CI 0.22 to 0.53), P<0.01). Rates of distal embolization (OR 1.60 (95% CI 0.69 to 3.70), P=0.27), symptomatic intracranial hemorrhage (OR 0.84 (95% CI 0.51 to 1.38), P=0.49), or iatrogenic dissection (OR 1.58 (95% CI 0.59 to 4.22), P=0.36) did not differ significantly between patient groups. Conclusions MT in patients with CeAD-related LVO is safe, effective, and associated with improved functional outcomes and lower mortality compared with patients with non-CeAD acute ischemic causes.

High-resolution imaging is critical for the diagnosis, treatment planning, and postoperative monitoring of cerebral aneurysms, which affect up to 5% of the population and pose a significant risk of rupture and subarachnoid hemorrhage. Surgical clipping remains a definitive treatment option, but metallic clips can introduce substantial imaging artifacts, complicating posttreatment assessment. This review synthesizes current knowledge on the impact of aneurysm clip materials and designs on artifact generation and explores strategies for artifact mitigation. Conventional materials like titanium are favored for their biocompatibility and reduced ferromagnetism but still cause beam hardening, streak artifacts, and signal loss in CT and MRI scans. Emerging alternatives, including ceramics, composites, polymers, and bioresorbable clips, show promise in reducing artifacts while maintaining mechanical reliability. Innovations in clip design, such as fenestrated or low-profile models, further aid in minimizing imaging distortion. Advanced imaging methods, including dual-energy CT, iterative reconstruction algorithms, and metal artifact reduction software, demonstrate significant improvements in image quality but may introduce limitations such as increased processing demands or subtle anatomical distortions. Future directions emphasize the development of next-generation clip materials, robotic-assisted surgical approaches, and artificial intelligence-driven reconstruction techniques to further optimize visualization and patient safety. Continued research and multidisciplinary collaboration will be essential to translate these innovations into routine neurosurgical practice.

Background Guide catheter (GC) placement, whether distal or proximal, may influence the efficacy and safety of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, definitions of placement and procedural strategies vary across studies, limiting clarity. Methods We systematically searched PubMed, Embase, Scopus, and Web of Science from inception to September 1, 2024. Comparative studies of adult patients with anterior circulation AIS-LVO undergoing MT that reported GC placement were included. Both balloon GCs (BGCs) and non-BGCs were eligible. Data were pooled using random-effects models in R. Outcomes included functional independence (modified Rankin Scale 0–2 at 90 days), successful reperfusion (modified thrombolysis in cerebral infarction ≥2b or expanded thrombolysis in cerebral infarction ≥2c), first-pass recanalization (FPR), mortality, puncture-to-recanalization (PTR) time, and complications. Subgroup analyses were performed by thrombectomy technique and catheter type. Results Seven retrospective studies comprising 2148 patients (1042 proximal, 1106 distal) were analyzed. Distal placement was associated with higher rates of functional independence (risk ratio (RR): 1.25, 95% confidence interval (CI): 1.10–1.42), successful reperfusion (RR: 1.13, 95% CI: 1.04–1.22), and FPR (RR: 1.35, 95% CI: 1.15–1.58), as well as lower 90-day mortality (RR: 0.52, 95% CI: 0.28–0.82). PTR time was shorter with distal placement (mean difference: −7.7 min, 95% CI: −10.8 to −4.6). No significant differences were observed for symptomatic intracranial hemorrhage (RR: 0.96, 95% CI: 0.55–1.65) or emboli to new territory (RR: 0.84, 95% CI: 0.28–2.52). Benefits were consistent across both BGCs and non-BGCs. Heterogeneity existed in outcome definitions and techniques, and publication bias could not be excluded. Conclusions Distal GC placement is associated with improved reperfusion, efficiency, and functional outcomes in MT for anterior circulation AIS-LVO, without increased complications. Given the retrospective nature of included studies, anatomic confounding, and inconsistent outcome definitions, findings should be considered preliminary. Multicenter trials are needed to confirm whether catheter position independently predicts MT outcomes.

Background Collateral status may facilitate clot removal and affect rates of successful reperfusion following endovascular therapy (EVT) for acute ischemic stroke (AIS). Methods Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Scopus, Web of Science, and Embase. Papers which focused on collateral status and patients treated with EVT for AIS were included in our analysis. Outcomes of interest included collateral score grading, rates of successful reperfusion defined as thrombolysis in cerebral infarction (TICI) score 2b-3 and onset to revascularization time. We calculated pooled odds ratio (OR) or mean difference (MD) and their corresponding 95% confidence intervals (CI) based on collateral status. Results 16 studies, with 6073 patients, were included in our analysis. Among the included studies, there were six different collateral grading scales, which were dichotomized into “good to moderate” and “poor” collaterals. Odds of successful reperfusion were significantly higher among patients with good to moderate collateral circulation compared to those with poor collaterals (OR = 1.61; 95% CI = 1.24 to 2.09; P -value < 0.001); however, there was heterogeneity among included studies (I2 = 5 4%; P -value = 0.008). Onset to revascularization time was comparable between patients with good to moderate collateral circulation compared to those with poor collaterals (MD = 3.91 min; 95% CI = −8.71 to 16.53; P -value = 0.544); however, there was heterogeneity among included studies (I2= 60%; P -value = 0.014). Conclusions The presence of good collaterals may increase the odds of achieving successful reperfusion following EVT for AIS. Improved collateral flow was associated with improved angiographic outcomes, although future work is needed to determine if a causal relationship exists.

Importance Patients with atrial fibrillation (AF) treated with mechanical thrombectomy (MT) for acute ischemic stroke (AIS) have been reported to experience worse outcomes compared with patients without AF. Objective To assess differences between patients with AF and their counterparts without AF treated with MT for AIS, focusing on safety outcomes, clinical outcomes, and baseline characteristics in both groups. Data Sources A systematic literature review of the English language literature from inception to July 14, 2022, was conducted using Web of Science, Embase, Scopus, and PubMed databases. Study Selection Studies that focused on patients with and without AF treated with MT for AIS were included. Multiple reviewers screened studies to identify studies included in analysis. Data Extraction and Synthesis Data were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline to ensure accuracy. Data were pooled using a random-effects model. Main Outcomes and Measures The primary outcome of interest was rate of modified Rankin Scale (mRS) scores of 0 to 2 at 90 days. Secondary outcomes of interest included rates of successful reperfusion, defined as thrombolysis in cerebral infarction (TICI) scores of 2b to 3, 90-day mortality, symptomatic intracranial hemorrhage (SICH), and baseline patient characteristics. Results Of 1696 initially retrieved studies, 10 studies were included, with 6543 patients. Patients with AF were a mean of 10.17 (95% CI, 8.11-12.23) years older ( P &amp;lt; .001) and had higher rates of hypertension (OR, 1.89 [95% CI, 1.57-2.27]; P &amp;lt; .001) and diabetes (OR, 1.16 [95% CI, 1.02-1.31]; P = .02). Overall, there were comparable rates of mRS scores of 0 to 2 between patients with AF and patients without AF (odds ratio [OR], 0.72 [95% CI, 0.47-1.10]; P = .13), with significant heterogeneity among the included studies. After sensitivity analysis, the rate of mRS scores of 0 to 2 was significantly lower among patients with AF (OR, 0.65 [95% CI, 0.52-0.81]; P &amp;lt; .001). Successful reperfusion rates were similar between the groups (OR, 1.11 [95% CI, 0.78-1.58]; P = .57). The rate of SICH was similar between groups (OR, 1.05 [95% CI, 0.84-1.31]; P = .68). Mortality was significantly higher in the AF group (OR, 1.47 [95% CI, 1.12-1.92]; P = .005). Conclusions and Relevance In this systematic review and meta-analysis, patients with AF experienced worse 90-day outcomes, even in the setting of similar rates of successful reperfusion. This was likely associated with greater age and greater rates of comorbidities among patients with AF.

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 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.