Kadirvel, Ramanathan

Background The first-pass effect (FPE) refers to the complete or near-complete revascularization with a single pass of mechanical thrombectomy devices. While previous claims suggest a link between larger catheters and the effectiveness of contact aspiration (CA) thrombectomy, no extensive research has confirmed if larger distal inner diameter (ID) catheters achieve higher FPE rates. Methods We searched PubMed, Scopus, and Web of Science to assess the impact of aspiration catheter distal ID size on FPE. The primary outcome was FPE rate, defined as thrombolysis in cerebral ischemia (TICI) grades 2c-3 at first pass, and the secondary outcome was modified FPE (TICI 2b-3 in a single pass). Aspiration catheters were categorized based on distal ID: 0.060–0.069 (medium bore), 0.070–0.074 (large bore), and greater than 0.074 inches (super-large bore). Rates of FPE were pooled using random effect models and compared using a Chi-square test. Results Our study included 34 articles with 4831 patients. FPE rates were 27.7% (95% CI, 15.1–45.3) for medium bore, 46.6% (95% CI, 33.7–59.9) for large, and 58.3% (95% CI, 44.8–70.7) for super-large catheters. The FPE rate was significantly higher for super-large bore catheters compared with other groups (χ² = 7.26, p = 0.03). A similar trend was observed for modified FPE rates, which were 51.1% (95% CI, 45.3–56.8) for medium bore, 60.0% (95% CI, 52.8–66.8) for large bore, and 80% (95% CI, 56.3–94.2) for super-large bore catheters (χ² = 8.14, p = 0.03). Conclusion Our analysis indicates that larger CA catheters are correlated with higher FPE rates.

Background Accurate and timely prehospital detection of large vessel occlusion (LVO) is critical for optimizing patient triage and initiating appropriate reperfusion therapies. Recent advances in portable stroke detection technologies, such as electroencephalography (EEG) and transcranial Doppler (TCD) ultrasound, offer potential solutions but their diagnostic performance remains unclear. Methods We searched PubMed, Scopus, Embase, and Web of Science, following the PRISMA guidelines. Studies were included if they assessed the diagnostic performance of non-invasive prehospital LVO detection tools compared to CT or MR angiography. Risk of bias was assessed using the QUADAS-2 tool. Results A total of 13 studies were included, examining various portable detection tools including EEG or neurophysiological monitoring, ultrasound-based techniques including TCD or TCCD, portable Openwater optical blood flow monitor and cranial accelerometry. The pooled diagnostic odds ratio (DOR) was 52.7 (95% CI: 28.3–97.8), indicating strong diagnostic performance, with significant heterogeneity among studies (I 2 = 67.3%, P < 0.001). Subgroup analysis revealed that TCD-based methods had the highest DOR (120.4, 95% CI: 76.9–188.7), followed by other tools (26.8, 95% CI: 13.7–52.6), and EEG (18.2, 95% CI: 9.1–36.3). The pooled sensitivity was 87.4% (95% CI: 82.5–91.0) and specificity was 89.39% (95% CI: 83.0–93.5) across all methods. TCD-based methods showed the highest specificity (95.0%, 95% CI: 91.8–97.0). Conclusion Non-invasive prehospital LVO detection tools show promising diagnostic performance, particularly TCD-based methods. Future studies should focus on validating these tools in larger, diverse populations to enhance prehospital stroke triage and improve patient outcomes.

Objective Aneurysm wall enhancement (AWE) is a potential biomarker of inflammation within the aneurysm wall that has been correlated with a higher risk of rupture. Aspirin (ASA) may decrease AWE due to its anti-inflammatory properties. We aimed to assess the effect of ASA on AWE in an animal model and a cohort of patients with unruptured intracranial aneurysms (UIAs). Methods Three rabbits with elastase-induced aneurysms were exposed to ASA for 8 weeks and three rabbits were used as controls. 3 T high-resolution magnetic resonance imaging (HR-MRI) was performed at 7 days and 8 weeks to evaluate changes in AWE through histological and immunohistological analyses. Additionally, we evaluated AWE in patients who underwent imaging with a 3 T HR-MRI protocol. ASA exposure was defined as daily intake of 81 mg for at least six months prior to HR-MRI. AWE was quantified using three-dimensional AWE maps and histograms. Results Among rabbits exposed to ASA, the mean AWE was lower at 8 weeks compared to the controls (2.11 vs 2.15, p = 0.13). Immunostaining of the aneurysm wall in rabbits that received ASA revealed a reduced expression of CD68 + or cyclooxygenase-2 + cells, compared to the controls. A total of 99 patients with 120 UIAs were included in the HR-MRI analysis of UIAs. UIAs exposed to ASA (22/120) had significantly lower median AWE than those that were not exposed (0.60 vs 0.72, p = 0.032). Conclusion ASA therapy is associated with an objective reduction in AWE, suggesting a potential role in lowering the risk of aneurysm rupture.

We have developed a cost-effective method to study the fate of stents, particularly flow diverter stents placed in the abdominal aorta, in a rat model. This technique utilizes (caudal) tail artery access,1–5 thereby avoiding the need for surgical exposure of the femoral or carotid arteries and reducing procedural invasiveness,6 7 aligning with the principles of refinement and reduction in animal research.7 This approach may be particularly beneficial for studies requiring multiple or iterative vascular access. The use of ultrasound guidance further reduces costs and infrastructure requirements by eliminating the need for specialized angiography suites.8 This makes this technique accessible to a broader range of research settings, promoting wider adoption and collaboration in the field of endovascular research. A detailed demonstration of this method is provided in the accompanying educational video (video 1). Video 1 -Technical video describing the tail artery access and flow diverter deployment using ultrasound guidance.

Objective: To evaluate the safety and efficacy of recombinant human prourokinase (rhPro-UK) administered via intravenous (IV) and intra-arterial (IA) routes in acute ischemic stroke (AIS) patients compared with standard treatments. Methods: A comprehensive search was conducted in accordance with PRISMA guidelines across Scopus, Web of Science, and PubMed until 11 December 2024. Randomized controlled trials (RCTs) assessing rhPro-UK’s efficacy and safety were included. Outcomes included the modified Rankin Scale (mRS), the National Institutes of Health Stroke Scale (NIHSS), mortality, and adverse events (AEs). Data analysis used risk difference (RD) with 95% confidence intervals (CIs). Results: Six RCTs (n = 3993) met the inclusion criteria. IV rhPro-UK showed comparable efficacy to the comparator for the mRS 0–1 at 90 days (RD: 0.00, 95% CI: [−0.04, 0.04]) and the mRS 0–2 (RD: −0.01, 95% CI: [−0.03, 0.01], P = 0.23). IA rhPro-UK significantly improved the mRS 0–1 (RD: 0.13, 95% CI: [0.01, 0.26], P = 0.04). The NIHSS reduction was significant for IV rhPro-UK (MD: −0.83, 95% [CI: −1.36, −0.29]). IV rhPro-UK did not significantly reduce the risk of systemic bleeding (RD: −0.10, 95% CI: [−0.24, 0.03], P = 0.12), serious AEs (RD: −0.01, 95% CI: [−0.04, 0.02], P = 0.53), or mortality (RD: 0.01, 95% CI: −0.01, 0.02). IA rhPro-UK significantly increased hemorrhage with neurological deterioration (RD: 0.08, 95% CI: [0.01, 0.14], P = 0.02). Conclusions: IV rhPro-UK provides non-inferior efficacy to both alteplase and standard care with a better safety profile at 35 mg, while IA rhPro-UK enhances functional outcomes in middle cerebral artery occlusions, albeit with safety concerns. Further trials are needed to confirm long-term outcomes, optimal dosing, and broader applicability.

Brain arteriovenous malformations (bAVMs) are a notable cause of intracranial hemorrhage, strongly associated with severe morbidity and mortality. Contemporary treatment options include surgery, stereotactic radiosurgery, and endovascular embolization, each of which has limitations. Hence, development of pharmacological interventions is urgently needed. The recent discovery of the presence of activating Kirsten rat sarcoma ( KRAS ) viral oncogene homologue mutations in most sporadic bAVMs has opened the door for a more comprehensive understanding of the pathogenesis of bAVMs and has pointed to entirely novel possible therapeutic targets. Herein, we review the status quo of genetics, animal models, and therapeutic approaches in bAVMs.

Background: Variability in recanalization success during endovascular treatment for acute ischemic stroke (AIS) has led to increased interests in thrombus composition and associated cellular materials. While evidence suggests that bacteria may influence thrombus characteristics, limited data exist on microbiological profiles of thrombi in stroke patients. Objectives: Characterization of bacterial communities present in thrombi of AIS patients undergoing mechanical thrombectomy, providing insights into microbial contributions to stroke pathogenesis and treatment outcomes. Methods: Thrombi were collected from 20 AIS patients. After extracting metagenome, 16S rDNA sequencing was performed. Bioinformatic analysis included taxonomy and diversity assessments. The presence of bacterial DNA and viable bacteria in thrombi was validated using polymerase chain reaction (PCR) and bacterial culturing followed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) analysis, respectively. Results: 16S rDNA was amplified in 19/20 thrombi (95%). Analysis identified a diverse microbial community, with Corynebacterium spp. as the most prevalent genus, followed by Staphylococcus spp., Bifidobacterium spp., Methylobacterium spp., and Anaerococcus spp. Alpha diversity analyses (Shannon index: 4.0–6.0 and Simpson index: 0.8–1.0) revealed moderate to high microbial diversity across samples; beta diversity demonstrated distinct clustering, indicating inter-patient variability in microbial profiles. PCR confirmed the presence of DNA specific to dominant bacterial taxa identified through sequencing. Culturing showed the presence of Staphylococcus epidermidis and Enterococcus faecalis in some clots as identified through MALDI analysis. Conclusions: This study shows bacterial communities present in AIS patients’ thrombi, suggesting a potential link between microbial signatures and thrombus characteristics.

Background Carotid artery tortuosity (CAT) may complicate mechanical thrombectomy (MT), potentially causing delays or preventing recanalization. However, the relationship between CAT and MT outcomes remains largely unexplored. This systematic review aims to evaluate the existing evidence regarding the impact of CAT on MT outcomes. Methods Following PRISMA guidelines, a systematic literature search was conducted using MEDLINE, EMBASE, Web of Science, Cochrane, and Scopus databases. Studies providing data for MT outcomes based on CAT status were included. Outcomes of interest included successful recanalization, first-pass efficacy (FPE), procedure time, functional independence, and procedure-related complications. Results Our search identified nine studies with 2737 patients. Three studies employed DSA to assess tortuosity, whereas the remaining six studies preferred CTA. In seven studies, CAT was associated with prolonged procedure times. In five studies, successful recanalization rates were significantly lower in CAT patients as compared to patients with non-tortuous arteries. Two studies showed that CAT could alter FPE or successful recanalization rates of first-line MT techniques. No study found statistically significant relationships between CAT and functional independence. Three studies examined the association between CAT and safety outcomes, and only one study found increased intracranial hemorrhage rates in patients with CAT. All nine studies employed different CAT criteria. Conclusions Despite the vast MT literature, the number of studies reporting CAT status remains low. CAT may affect procedure time and technical outcomes of MT. Therefore, employing a uniform CAT definition and reporting CAT more frequently can provide insights into management of patients with acute large vessel occlusions.

Background Left ventricular assist devices (LVADs) are used as definitive therapy or as a bridge to heart transplant in patients with advanced heart failure. Thromboembolic complications such as acute ischemic stroke (AIS) are common among patients with LVAD support. This study aims to evaluate the current evidence on the efficacy and safety of mechanical thrombectomy (MT) in patients with AIS due to large vessel occlusions (LVO) and LVAD-support. Methods A comprehensive systematic review was conducted in PubMed, Embase, and Scopus to find observational studies with reports of ≥5 MTs in adult patients with LVAD support (PROSPERO registration code CRD42024597541). Rates of successful and complete reperfusion, favorable functional outcomes at 90 days (modified Rankin Scale (mRS) 0–2 or equal to pre-stroke mRS), mortality at 90 days, any intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) were pooled using generalized linear mixed models. Results Eight studies were included with data from 51 patients and 62 MTs. The rate of successful reperfusion was 87.4% (95% CI 62.5% to 96.6%) and complete reperfusion rate was 57.3% (95% CI 35.1% to 76.9%). Rate of favorable functional recovery was 62.5% (95% CI 42.2% to 79.2%). Rate of sICH was 6.4% (95% CI 0.9% to 34.0%). Mortality rate was 16.7% (95% CI 7.1% to 34.7%). Between 25–40% of patients who were waiting for a heart transplant before their stroke received a heart transplant after MT. Conclusions MT for the emergent treatment of AIS in the setting of LVAD is relatively safe and efficacious for achieving successful reperfusion and good functional recovery.

Background The impact of certain comorbidities on mechanical thrombectomy (MT) outcomes remains largely unexplored. Diabetes mellitus (DM) and admission hyperglycemia have been associated with poor clinical outcomes for patients treated with MT. In this study, we sought to investigate the effects of DM and admission hyperglycemia on MT outcomes. Methods Following PRISMA guidelines, a systematic literature search was conducted in Medline, Embase, Scopus, and Web of Science databases. Data regarding successful recanalization (modified Thrombolysis in Cerebral Infarction [mTICI] ≥2b), functional independence (modified Rankin Scale [mRS] 0–2), excellent outcomes (mRS 0–1), symptomatic intracranial hemorrhage (sICH), and mortality were extracted from the included studies. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated using random effects model. Results Twenty-one studies comprising 9708 patients were included. A total of 2311 patients (24%) had a history of DM, and 2026 patients (21%) had admission hyperglycemia. Admission hyperglycemia was associated with significantly lower odds of mTICI ≥2b (OR = 0.7, 95% CI = 0.55–0.89), mRS 0–2 (OR = 0.47, 95% CI = 0.41–0.53), and mRS 0–1 (OR = 0.43, 95% CI = 0.34–0.55) as compared to normoglycemic state. Patients with hyperglycemia had significantly higher rates of sICH (OR = 2.05, 95% CI = 1.66–2.54) and mortality (OR = 1.99, 95% CI = 1.58–2.52) than normoglycemic patients. Diabetes mellitus was associated with significantly high rates of mortality (OR = 1.74, 95% CI = 1.31–2.3) and lower rates of mRS 0–2 (OR = 0.60, 95% CI = 0.48–0.76) in sensitivity analyses. Conclusion Our results indicate that admission blood glucose levels and DM can negatively affect MT outcomes. Further research should focus on optimizing MT outcomes for these patients.