Kallmes, David F.

AbstractObjectiveAbout 25% of patients with acute ischemic stroke (AIS) present within the intravenous thrombolytic (IVT) therapeutic window of <4.5 h. This study is to elucidate the safety and efficacy of IVT in the extended therapeutic window (ETW) in patients with AIS.MethodsUsing PRISMA guidelines, a systematic review was conducted using PubMed, Embase, and Scopus. A rigorous risk of bias assessment was conducted using the RoB2 tool. Rates of excellent and good functional outcome (mRS 0–1 and mRS 0–2) at 90 days, symptomatic intracranial hemorrhage (sICH), and mortality at 90 days were pooled using generalized linear mixed model and compared with controls. Meta‐analyses were conducted employing random‐effect models with risk ratio (RR) and 95% confidence intervals (CIs). Subgroup analysis was performed to assess the effect of imaging modalities used for patient selection.ResultsEight randomized controlled trials (n = 2221, 59% male) were included. At 90 days IVT showed higher rates of functional recovery: mRS 0–1: RR 1.21 95% CI 1.1–1.34, p < 0.001, and mRS 0–2: RR 1.11 95% CI 1.03–1.18, p = 0.004. Rate of mortality at 90 day was not different between groups: RR 1.17 95% CI 0.93–1.48, p = 0.17. However, the rate of sICH was higher among IVT group: RR 2.93 95% CI 1.53–5.6, p = 0.001. Subgroup analysis showed higher mRS 0–1 among patients who were selected based on perfusion imaging (p < 0.05).InterpretationThe use of IVT in AIS in ETW is beneficial especially with the use of perfusion imaging for patients' selection.

Background The choice of angiography system could influence the outcomes of mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS), but its impact is not yet well understood. This study aims to compare the clinical and technical outcomes of MT performed with single plane versus biplane angiography systems. Method We conducted a systematic review and meta-analysis, following PRISMA guidelines, by searching PubMed, Embase, Web of Science, and Scopus to include studies on patients with AIS who underwent MT with either single plane or biplane angiography up to May 4, 2024. The primary outcome was a favorable outcome defined as a modified Rankin Scale (mRS) score of 0–2 at 90 days after the procedure. Data were analyzed using a random-effects model and heterogeneity was assessed using the I2 test and Q statistics. Results Five studies with a total of 1562 patients were analyzed. Of these, 68.4% were treated with biplane systems and 31.6% with single plane systems. Single plane angiography was associated with a significantly higher rate of favorable outcomes (OR 1.43; 95% CI 1.13 to 1.80; P<0.01). There were no significant differences in successful recanalization, periprocedural complications, procedure time, total fluoroscopy time, or contrast volume between the two systems. Conclusion While single plane angiography systems may offer slightly better outcomes in MT for AIS, both systems appear equally effective in most clinical and technical perspectives, suggesting that system selection may be more dependent on availability and procedural requirements rather than inherent superiority. Our findings may encourage clinicians to use single-plane angiography in settings where the biplane angiography suite availability is limited, but it should be noted that this observation may have been influenced by selection bias, particularly since the larger studies included in our meta-analysis did not observe this effect in adjusted analyses for potential confounder factors.

Background The angiographic shape of an occlusion, like the clot meniscus sign and the claw sign, has been reported to potentially impact the recanalization rate and clinical outcome in patients undergoing mechanical thrombectomy for acute ischemic strokes. Method Following PRISMA guidelines, a systematic literature search was conducted across PubMed, Scopus, Embase and Web of Science databases. Patients were grouped into clot meniscus/claw sign positive and negative groups based on the definitions obtained from each study. Primary outcomes included technical success, with a meta-analysis performed using a random-effects model to calculate proportions and odds ratios (OR) with 95% confidence intervals (Cl). Results We included seven studies recruiting 1572 patients. The results indicated that the positive and negative groups had comparable first-pass effect (OR 1.95; 95% CI 0.76 to 5.01; P=0.167) and final recanalization (OR 1.36; 95% CI 0.81 to 2.27; P=0.248) rates. However, the rate of having a favorable functional outcome was significantly higher in the positive group than in the negative sign group (OR 1.91; 95% CI 1.25 to 2.92; P<0.003). Within the sign-positive population, the use of contact aspiration was associated with a significantly higher rate of recanalization compared with using a stent retriever (OR 0.18; 95% CI 0.07 to 0.49; P<0.001). This result did not translate into a clinical impact, as both stent retriever and contact aspiration showed comparable rates of functional independence at 3 months (OR 0.22; 95% CI 0.02 to 2.33; P=0.210). Conclusion The presence of the clot meniscus/claw sign is not associated with recanalization outcomes after thrombectomy. However, it might be a good sign to predict which thrombectomy technique might be associated with better recanalization, although current evidence may need further confirmation.

Background The pipeline embolization device (PED) has been increasingly used to treat brain aneurysms; however, concerns have been raised about braid stability with newer drawn filled tubing technology devices. Objective To evaluate braid stability of PED early generations using data from the PREMIER trial. Methods All consecutive intracranial aneurysms treated with PED (Classic and Flex) within the PREMIER trial were reviewed for braid stability (fish mouthing, foreshortening, braid bump, braid collapsing). Immediate postprocedure cone-beam CT and angiography were compared with 1- and 2- years' follow-up. Analyses included safety, measured with the modified Rankin Scale (mRS) score, including +1 mRS point and a good clinical outcome (mRS score 0–2), vessel stenosis ≥50%, effectiveness measured with Raymond-Roy Scale, and re-treatment rates. Results 133/141 aneurysms had a complete dataset. 8/133 (6%) aneurysms showed braid deformations. Inter-reader agreement was excellent (κ=0.83). Braid deformations were statistically significantly associated with in-stent vessel stenosis >50% (P=0.029), without impact on effectiveness or safety. Fish mouthing was found in 1/133 (0.75%) at 1 year, causing >50% vessel stenosis. Foreshortening occurred in 6/133 (4.5%), and braid bump in 1/133 (0.75%) associated with severe in-stent stenosis. Four other cases (3.0%) of asymptomatic in-stent stenosis due to neointimal hyperplasia were seen without braid changes. No new braid stability deformations were found at the 2-year follow-up. Conclusion Our study demonstrates excellent braid stability among patients treated with the PED Classic and Flex in the PREMIER trial. Within the uncommon braid changes observed, none affected the PED safety or efficacy. Trial registration number NCT02186561 .

Background Cerebral sinus venous thrombosis (CSVT) has traditionally been treated medically with systemic anticoagulation. Recent advances in endovascular therapy (EVT) may represent an alternative treatment to medical therapy for CSVT. We conducted a systematic review and meta-analysis to evaluate the use of EVT for CSVT. Methods We conducted a systematic literature review using PubMed, Embase, Scopus, and Web of Science. We included studies that reported outcomes following EVT for CSVT. The primary outcome of interest was rate of modified Rankin Scale (mRS) 0–2. Secondary outcomes of interest were rates of complete, partial, and failed recanalization, mortality, and new or expansion of hematoma. We calculated pooled rates (%) and their corresponding 95% confidence intervals (CIs). Results Thirty-eight studies with 682 patients were included. Rate of mRS 0–2 was 82.6% (95% CI, 75.3%–88.0%). Rate of complete recanalization was 60.9% (95% CI, 49.1%–71.5%), rate of partial recanalization was 34.2% (95% CI, 24.1%–45.9%), and rate of failed recanalization was 5.4% (95% CI, 3.1%–9.2%). Rate of mortality was 6.7% (95% CI, 4.1%–10.8%), and rate of new hematoma or expansion of hematoma was 5.1% (2.9%–8.8%). Conclusions In this systematic review and meta-analysis, EVT for CSVT was associated with favorable rates of mRS 0–2 and recanalization. Furthermore, EVT was associated with a promising safety profile. Future prospective, comparative studies are warranted to assess EVT for CSVT.

Background Many devices are used to perform mechanical thrombectomy in the setting of large vessel occlusion acute ischemic stroke. We sought to evaluate the efficacy and safety of pRESET stent-retriever systems. Methods We conducted a comprehensive systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies up to March 2024 were retrieved from PubMed, Scopus, Web of Science, and Embase databases. Results A total of 8 papers met the inclusion/exclusion criteria comprising a total of 1140 participants (average age 72.4 ± 11.9, female percentage (50%). Preintervention intravenous thrombolysis was utilized in 46.5% (range 32.9–65.4) of patients, with a median National Institute of Health Stroke Scale at presentation of 15 (range 0–38). The middle cerebral artery was the most commonly affected artery, with a prevalence of 76.4% (range 62.8–100). The pRESET stent-retriever systems demonstrated a first-passing effect rate of 53.4% [95% confidence interval [CI] 44.8; 61.7] and a final thrombolysis in cerebral infarction 2b-3 grade rate of 90.41% [95% CI 82.13; 95.08]. Ninety-day modified Rankin Scale (0–2) rate was 42.2% [95% CI 27.6; 58.4], and 90-day mortality rate was 15.1% [95% CI 9.8; 22.6]. Postintervention hemorrhage occurred at a rate of 28.6% [CI 17.2; 43.6]. Conclusion Our systematic review and meta-analysis describes the efficacy of the pRESET stent retriever system in managing acute ischemic stroke patients. The pRESET device was found to have a similar safety and efficacy profile to other mechanical thrombectomy devices currently in use.

Purpose Optimizing the preparation of a 10 ml syringe for manual injection of contrast media can help operators obtain easier and faster injections. This study aims to compare the flow rates of different contrast media injection methods. Methods Different contrast media solutions were compared: 100% contrast (10 ml contrast), mixed contrast solution (8:2 contrast/saline), and layered contrast below saline (“Parfait”) in different volumes. Contrast media were injected at room temperature (20°C) and after heating (37°C). Four operators injected 10 ml syringes filled with different mediums through 5-French angiographic catheters. The average flow rate was used to compare different contrast injection mediums. The Kruskal-Wallis test with post-hoc pairwise comparisons using Bonferroni correction or Mann-Whitney U-tests were employed depending on the type of comparison. Results Compared to the 100% contrast solution, every Parfait media and mixed contrast solution demonstrated significantly higher flow rates (p < 0.001). The 5 ml saline Parfait had the highest flow rate among the Parfait solutions. The 5 ml saline Parfait and the mixed solution had comparable flow rates (p = 0.237). Higher flow rates were observed upon heating both 100% contrast (p < 0.001) and mixed contrast solutions (p < 0.001) in comparison to their flow rates at room temperature. Conclusion This study demonstrates the capability of the Parfait and mixed contrast injections to achieve higher flow rates than the 100% contrast solutions. Heating the contrast media to 37°C also proves to be a viable strategy for further enhancing the flow rates for 100% and mixed contrast solutions.

Background and purpose Treatment of recurrent intracranial aneurysms after their initial therapy has been a significant challenge in the field of neurointervention. Recently flow diverters stents are widely used for treating intracranial aneurysms. In this systematic review and meta-analysis, we assessed the safety and efficacy of flow diverter in treating recurrent or recanalized intracranial aneurysms. Methods This meta-analysis is reported following the PRISMA 2020 guidelines. We conducted a systematic review of literature in the PubMed, Embase, Web of Sciences, and Scopus databases. Pooled prevalence and the corresponding 95% are calculated from extracted data using a random-effect model. Results The systematic literature search included 21 studies involving 411 patients, with 135 (32.8%) being male and 276 (67.2%) being females with a total number of 447 aneurysms. The overall rate of adequate occlusion was 90.67% (95% CI: 84.23%–94.65%), and the rates were comparable between the surgery (93.48%), coiling (91.78%), and stenting (85.77%) groups. The overall pooled rate of complete occlusion was 81.80 (95% CI: 71.14%–89.13%). On doing a subgroup analysis, the complete occlusion rates were 89.68%, 84.39%, and 73.47% for the surgery, coiling, and stenting groups, respectively. The overall mortality rate and achieving modified Rankin scale score of 0-2 was 1.28% (95% CI: 0.45%–3.64%) and (95% CI: 89.92%–97.84%), respectively. No significant heterogeneity is noted in the included studies. Conclusion Flow diverter stents are an effective and safe method for retreating recurrent or residual intracranial aneurysms with a high rate of complete and adequate occlusion. The rate of mortality, intracerebral hemorrhage, and overall and procedural complications following using flow diverters for intracranial aneurysms is low.

Background Although flow diverters (FDs) have benefited from several technical improvements, recently concerns have arisen regarding the braid stability after implantation. Thus, we investigated frequency, predictive factors, and clinical impact of the phenomenon of FD braid deformation (FDBD). Methods Consecutive intracranial aneurysms (IAs) treated with various FDs, between January 2018 and July 2023, were reviewed to identify FDBD (defined as the deformation of a FD without any external force applied to it). Patient, aneurysm, procedural, and FD characteristics were retrieved and analyzed using univariate and multivariable analyses. Morbidity is defined as a score of +1 in the modified Rankin Scale at 3 months. Results In total, 245 FD procedures (271 FDs implanted; 25 multiple IAs treated with 1 FD) in 228 patients; FDBD was observed in 36/245 cases (14.7%), mainly at follow-up angiography (32/36, 88.9%); fish-mouthing was the most frequent FDBD. Morbidity was related to fish-mouthing and braid collapse and was significantly higher in the FDBD group after retreatment (p=0.04). Drawn filled tubing with platinum (DFT) (adjusted odds ratio (aOR)=7.0, 95% CI 3.0 to 17.5; p<0.001) and FD diameter (aOR=2.2, 95% CI 1.3 to 4.1; p<0.01) were identified as independent predictors of FDBD. The metal alloy composing the FD (p=0.13) and coated surfaces were not significantly associated with FDBD (p=0.54 in multivariable analysis). Conclusions FDBD is a frequent phenomenon observed in about 15% of cases, and it was responsible for higher morbidity. Only FD characteristics (DFT and FD diameter) were independent determinants of FDBD. Future research should focus on the impact of novel braid configurations and materials on braid stability.