MT 81

Objective: Mechanical thrombectomy (MT) is not recommended for acute stroke with large vessel occlusion (LVO) and a large volume of irreversibly injured tissue ("core"). Perfusion imaging may identify a subset of patients with large core who benefit from MT. Methods: We compared two cohorts of LVO-related patients with large core (>50 ml on diffusion-weighted-imaging or CT-perfusion using RAPID), available perfusion imaging, and treated within 6 hours from onset by either MT + Best Medical Management (BMM) in one prospective study, or BMM alone in the pre-MT era from a prospective registry. Primary outcome was 90-day modified Rankin Scale ≤2. We searched for an interaction between treatment group and amount of penumbra as estimated by the mismatch ratio (MMRatio = critical hypoperfusion/core volume). Results: Overall, 107 patients were included (56 MT + BMM and 51 BMM): Mean age was 68 ± 15 years, median core volume 99 ml (IQR: 72-131) and MMRatio 1.4 (IQR: 1.0-1.9). Baseline clinical and radiological variables were similar between the two groups, except for a higher intravenous thrombolysis rate in the BMM group. The MMRatio strongly modified the clinical outcome following MT (pinteraction < 0.001 for continuous MMRatio); MT was associated with a higher rate of good outcome in patients with, but not in those without, MMRatio>1.2 (adjusted OR [95% CI] = 6.8 [1.7-27.0] vs 0.7 [0.1-6.2], respectively). Similar findings were present for MMRatio ≥1.8 in the subgroup with core ≥70 ml. Parenchymal hemorrhage on follow-up imaging was more frequent in the MT + BMM group regardless of the MMRatio. Interpretation: Perfusion imaging may help select which patients with large core should be considered for MT. Randomized studies are warranted. ANN NEUROL 2021;90:417-427.

Purpose: To investigate the difference in mechanical thrombectomy (MT) outcomes between vertebrobasilar tandem occlusion (VBTO) and isolated basilar artery (BA) occlusion (non-VBTO) and the difference in rates of successful recanalization between the clean-road and dirty-road pathways, in VBTO. Methods: We conducted a meta-analysis after searching PubMed, EMBASE, and Google Scholar databases as of April 2021. We only included adult patients who underwent MT to treat acute ischemic stroke (AIS) due to VBTO, and the following outcomes should be reported: successful recanalization, functional outcome at 90 days, and symptomatic intracerebral hemorrhage (sICH). The main effect size measures were odds ratio and risk difference, and the software used was RevMan 5.4. Results: The analysis included 81 VBTO and 324 non-VBTO patients (seven studies). We found no significant difference regarding 3 m functional independence [4 studies: OR = 1.71 (95% CI, 0.54, 5.43), I2 = 75%], 3 m mortality [4 studies: OR = 1.62 (95% CI, 0.62, 4.25), I2 = 66%], sICH [4 studies: OR = 1.71 (95% CI, 0.67, 4.39), I2 = 0%], and successful recanalization [3 studies: OR = 0.81 (95% CI, 0.12, 5.57), I2 = 80%]. A subgroup analysis of 118 VBTO patients (five studies) showed no significant difference in successful recanalization between clean-road and dirty-road pathways [RD = 0.07 (95% CI, - 0.09, 0.24), I2 = 40%]. Conclusion: The results of this meta-analysis support the use of MT for AIS patients with VBTO. In VBTO patients, none of the clean-road or dirty-road pathways proved to be superior to the other.

This study represents the first quantitative global prediction of the mass distribution of six widespread polymers, plus plastic fibers and rubber across four environmental compartments and 11 sub-compartments. The approach used probabilistic material flow analysis for 2015, with model input values and transfer coefficients between compartments taken from literature. We estimated that 3.2 ± 1.8 Mt/year of polyethylene, 1.3 ± 0.8 Mt/year of polypropylene, 0.5 ± 0.3 Mt/year of polystyrene, 0.3 ± 0.15 Mt/year of polyvinyl chloride, 1.6 ± 0.9 Mt/year of polyethylene terephthalate and 2.4 ± 1.2 Mt/year of plastic fibers enter the environment. Combining all plastic, including rubber, 4.9 ± 1.3, 4.8 ± 1.9 and 1.8 ± 1.2 Mt/year accumulated in the soil, ocean, and freshwater, respectively. Urban soils and ocean shorelines were predicted as hotspots for plastic accumulation, accounting for 33% and 25% of total plastic, respectively. The floor of freshwater systems and the ocean were predicted as hotspots for high density plastic such as polyethylene terephthalate, polyvinyl chloride and plastic fibers. Furthermore, 59% of environmental rubber was predicted to accumulate in soil. The findings of this study provide baseline data for quantifying plastic transport and accumulation, which can inform future ecotoxicity studies and risk assessments, as well as targeting efforts to mitigate plastic pollution.