Early Postmarket Results with EmboTrap II Stent Retriever for Mechanical Thrombectomy: A Multicenter Experience.

BACKGROUND AND PURPOSE: EmboTrap II is a novel stent retriever with a dual-layer design and distal mesh designed for acute ischemic stroke emergent large-vessel occlusions. We present the first postmarket prospective multicenter experience with the EmboTrap II stent retriever. MATERIALS AND METHODS: A prospective registry of patients treated with EmboTrap II at 7 centers following FDA approval was maintained with baseline patient characteristics, treatment details, and clinical/radiographic follow-up. RESULTS: Seventy patients were treated with EmboTrap II (mean age, 69.9 years; 48.6% women). Intravenous thrombolysis was given in 34.3%, and emergent large-vessel occlusions were located in the ICA (n = 18), M1 (n = 38), M2 or M3 (n = 13), and basilar artery (n = 1). The 5 × 33 mm device was used in 88% of cases. TICI ≥ 2b recanalization was achieved in 95.7% (82.3% in EmboTrap II-only cases), and first-pass efficacy was achieved in 35.7%. The NIHSS score improved from a preoperative average of 16.3 to 12.1 postprocedure and to 10.5 at discharge. An average of 2.5 [SD, 1.8] passes was recorded per treatment, including non-EmboTrap attempts. Definitive treatment was performed with an alternative device (aspiration or stent retriever) in 9 cases (12.9%). Some hemorrhagic conversion was noted in 22.9% of cases, of which 4.3% were symptomatic. There were no device-related complications. CONCLUSIONS: Initial postmarket results with the EmboTrap II stent retriever are favorable and comparable with those of other commercially available stent retrievers. Compared with EmboTrap II, the first-generation EmboTrap may have a higher first-pass efficacy; however, data are limited by retrospective case analysis, incomplete clinical follow-up, and small sample size, necessitating future trials.

Transradial Approach for Neuroendovascular Procedures: A Single-Center Review of Safety and Feasibility.

BACKGROUND AND PURPOSE: In recent years, the transradial approach has become more widely adopted for neuroendovascular procedures. The purpose of this study was to evaluate the safety and feasibility of a transradial approach and distal transradial access for neuroendovascular procedures in a single center. MATERIALS AND METHODS: Retrospective analysis was performed for all patients who underwent transradial approach or distal transradial access neuroendovascular procedures from January 2016 to August 2019 at a single center. Exclusion criteria included a Barbeau D waveform, a radial artery of <2 mm on sonographic evaluation, and known radial artery occlusion. Procedures were evaluated for technical success (defined as successful radial artery access and completion of the intended procedure without crossover to an auxiliary access site), complications, and adverse events during follow-up at 30 days. RESULTS: The transradial approach or distal transradial access was attempted in 279 consecutive patients (58.1% women; median age, 57.7 years) who underwent 328 standard or distal transradial approach procedures. Two-hundred seventy-nine transradial approach and 49 distal transradial approach procedures were performed (cerebral angiography [n = 213], intracranial intervention [n = 64], head and neck intervention [n = 30], and stroke intervention [n = 21]). Technical success was 92.1%. Immediate adverse events (2.1%) included radial access site hematoma (n = 5), radial artery occlusion (n = 1), and acute severe radial artery spasm (n = 1). Thirty-day adverse events (0.3%) included a radial artery pseudoaneurysm (n = 1). Twenty-six cases (7.9%) required crossover to transfemoral access. CONCLUSIONS: The transradial approach for neuroendovascular procedures is safe and feasible across a wide range of neuroendovascular interventions.

Defining Ischemic Core in Acute Ischemic Stroke Using CT Perfusion: A Multiparametric Bayesian-Based Model.

BACKGROUND AND PURPOSE: The Bayesian probabilistic method has shown promising results to offset noise-related variability in perfusion analysis. Using CTP, we aimed to find optimal Bayesian-estimated thresholds based on multiparametric voxel-level models to estimate the ischemic core in patients with acute ischemic stroke. MATERIALS AND METHODS: Patients with anterior circulation acute ischemic stroke who had baseline CTP and achieved successful recanalization were included. In a subset of patients, multiparametric voxel-based models were constructed between Bayesian-processed CTP maps and follow-up MRIs to identify pretreatment CTP parameters that were predictive of infarction using robust logistic regression. Subsequently CTP-estimated ischemic core volumes from our Bayesian model were compared against routine clinical practice oscillation singular value decomposition-relative cerebral blood flow <30%, and the volumetric accuracy was assessed against final infarct volume. RESULTS: In the constructed multivariate voxel-based model, 4 variables were identified as independent predictors of infarction: TTP, relative CBF, differential arterial tissue delay, and differential mean transit time. At an optimal cutoff point of 0.109, this model identified infarcted voxels with nearly 80% accuracy. The limits of agreement between CTP-estimated ischemic core and final infarct volume ranged from -25 to 27 mL for the Bayesian model, compared with -61 to 52 mL for oscillation singular value decomposition-relative CBF. CONCLUSIONS: We established thresholds for the Bayesian model to estimate the ischemic core. The described multiparametric Bayesian-based model improved consistency in CTP estimation of the ischemic core compared with the methodology used in current clinical routine.

The Use and Utility of Aspiration Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

BACKGROUND: Thrombectomy trials are often specifically interpreted as evidence for the effectiveness of stent retrievers. The effectiveness of other thrombectomy techniques such as aspiration thrombectomy should be validated through further investigation and review. PURPOSE: To evaluate published treatment times and clinical outcomes in patients treated with aspiration thrombectomy or ADAPT (A Direct Aspiration, First Pass Technique) for acute ischemic stroke. DATA SOURCES: A systematic literature review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Scopus, and the Cochrane trial register were searched on November 8, 2016. STUDY SELECTION: Twenty studies (n = 1523 patients) were included in this review and meta-analysis. One of these studies was prospective, and the rest were retrospective. DATA ANALYSIS: Meta-analysis was performed by using a random effects model. Data and publication bias were visualized with forest plots and funnel plots. DATA SYNTHESIS: Five studies investigated aspiration thrombectomy only, and 16 studies investigated ADAPT. Of the 16 studies on ADAPT, the rate of successful recanalization (TICI 2b/3) was 89.3% (95% CI, 85.4%-92.3%). The proportion of patients with good clinical outcome (90-day mRS ≤2) was 52.7% (95% CI, 48.0%-57.4%). LIMITATIONS: Studies on ADAPT were retrospective, and there was heterogeneity between studies for successful recanalization (P < .001) and good clinical outcome (P < .001). There was evidence of publication bias for recanalization rates (P = .01), but not for clinical outcomes (P = .42). CONCLUSIONS: ADAPT and aspiration thrombectomy are effective approaches to thrombectomy, with high recanalization rates and excellent clinical outcomes reported in the literature. Aspiration thrombectomy is a promising neurointervention, but large prospective randomized studies are needed to validate its utility.