80 research outputs found

    Do 7-year-old children understand social leverage?

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    Individuals with an advantageous position during a negotiation possess leverage over their partners. Several studies with adults have investigated how leverage can influence the coordination strategies of individuals when conflicts of interest arise. In this study, we explored how pairs of 7-year-old children solved a coordination game (based on the Snowdrift scenario) when one child had leverage over the other child. We presented a social dilemma in the form of an unequal reward distribution on a rotating tray. The rotating tray could be accessed by both children. The child who waited longer to act received the best outcome, but if both children waited too long, they would lose the rewards. In addition, one child could forgo the access to the rotating tray for an alternative option—the leverage. Although children rarely used their leverage strategically, children with access to the alternative were less likely to play the social dilemma, especially when their leverage was larger. Furthermore, children waited longer to act as the leverage decreased. Finally, children almost never failed to coordinate. The results hint to a trade-off between maximizing benefits while maintaining long-term collaboration in complex scenarios where strategies such as turn taking are hard to implement.PostprintPeer reviewe

    Association between time to reperfusion and outcome is primarily driven by the time from imaging to reperfusion

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    Background and Purpose A progressive decline in the odds of favorable outcome as time to reperfusion increases is well known. However, the impact of specific workflow intervals is not clear.; Methods We studied the mechanical thrombectomy group (n=103) of the prospective, randomized REVASCAT (Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset) trial. We defined 3 workflow metrics: time from symptom onset to reperfusion (OTR), time from symptom onset to computed tomography, and time from computed tomography (CT) to reperfusion. Clinical characteristics, core laboratory-evaluated Alberta Stroke Program Early CT Scores (ASPECTS) and 90-day outcome data were analyzed. The effect of time on favorable outcome (modified Rankin scale, 0-2) was described via adjusted odds ratios (ORs) for every 30-minute delay.; Results Median admission National Institutes of Health Stroke Scale was 17.0 (14.0-20.0), reperfusion rate was 66%, and rate of favorable outcome was 43.7%. Mean (SD) workflow times were as follows: OTR: 342 (107) minute, onset to CT: 204 (93) minute, and CT to reperfusion: 138 (56) minute. Longer OTR time was associated with a reduced likelihood of good outcome (OR for 30-minute delay, 0.74; 95% confidence interval [CI], 0.59-0.93). The onset to CT time did not show a significant association with clinical outcome (OR, 0.87; 95% CI, 0.67-1.12), whereas the CT to reperfusion interval showed a negative association with favorable outcome (OR, 0.72; 95% CI, 0.54-0.95). A similar subgroup analysis according to admission ASPECTS showed this relationship for OTR time in ASPECTS<8 patients (OR, 0.56; 95% CI, 0.35-0.9) but not in ASPECTS8 (OR, 0.99; 95% CI, 0.68-1.44).; Conclusions Time to reperfusion is negatively associated with favorable outcome, being CT to reperfusion, as opposed to onset to CT, the main determinant of this association. In addition, OTR was strongly associated to outcome in patients with low ASPECTS scores but not in patients with high ASPECTS scores.; Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01692379.Peer ReviewedPostprint (author's final draft

    Endovascular Treatment of Acute Ischemic Stroke With the Penumbra System in Routine Practice: COMPLETE Registry Results

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    Ischemic stroke; Reperfusion; ThrombectomyIctus isquèmic; Reperfusió; TrombectomiaIctus isquémico; Reperfusión; TrombectomiaBackground and Purpose: The purpose of the COMPLETE (International Acute Ischemic Stroke Registry With the Penumbra System Aspiration Including the 3D Revascularization Device) registry was to evaluate the generalizability of the safety and efficacy of the Penumbra System (Penumbra, Inc, Alameda) in a real-world setting. Methods: COMPLETE was a global, prospective, postmarket, multicenter registry. Patients with large vessel occlusion–acute ischemic stroke who underwent mechanical thrombectomy using the Penumbra System with or without the 3D Revascularization Device as frontline approach were enrolled at 42 centers (29 United States, 13 Europe) from July 2018 to October 2019. Primary efficacy end points were successful postprocedure angiographic revascularization (modified Thrombolysis in Cerebral Infarction ≥2b) and 90-day functional outcome (modified Rankin Scale score 0–2). The primary safety end point was 90-day all-cause mortality. An imaging core lab determined modified Thrombolysis in Cerebral Infarction scores, Alberta Stroke Program Early CT Scores, clot location, and occurrence of intracranial hemorrhage at 24 hours. Independent medical reviewers adjudicated safety end points. Results: Six hundred fifty patients were enrolled (median age 70 years, 54.0% female, 49.2% given intravenous recombinant tissue-type plasminogen activator before thrombectomy). Rate of modified Thrombolysis in Cerebral Infarction 2b to 3 postprocedure was 87.8% (95% CI, 85.3%–90.4%). First pass and postprocedure rates of modified Thrombolysis in Cerebral Infarction 2c to 3 were 41.5% and 66.2%, respectively. At 90 days, 55.8% (95% CI, 51.9%–59.7%) had modified Rankin Scale score 0 to 2, and all-cause mortality was 15.5% (95% CI, 12.8%–18.3%). Conclusions: Using Penumbra System for frontline mechanical thrombectomy treatment of patients with large vessel occlusion–acute ischemic stroke in a real-world setting was associated with angiographic, clinical, and safety outcomes that were comparable to prior randomized clinical trials with stringent site and operator selection criteria.This study was funded by Penumbra, Inc (Alameda). Drs Zaidat, Fifi, and A.E. Hassan were involved in study design. The sponsor was responsible for database setup, site monitoring, data management, and statistical analysis

    Skyrmions in nanorings: a versatile platform for Skyrmionics

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    The dynamical properties of skyrmions can be exploited to build devices with new functionalities. Here, we first investigate a skyrmion-based ring-shaped device by means of micromagnetic simulations and Thiele equation. We subsequently show three applications scenarios: (1) a clock with tunable frequency that is biased with an electrical current having a radial spatial distribution, (2) an alternator, where the skyrmion circular motion driven by an engineered anisotropy gradient is converted into an electrical signal, and (3) an energy harvester, where the skyrmion motion driven by a thermal gradient is converted into an electrical signal, thus providing a heat recovery operation. We also show how to precisely tune the frequency and amplitude of the output electrical signals by varying material parameters, geometrical parameters, number and velocity of skyrmions, and we further prove the correct device functionality under realistic conditions given by room temperature and internal material defects. Our results open a new route for the realization of energy efficient nanoscale clocks, generators, and energy harvesters

    Catheter tip distensibility substantially influences the aspiration force of thrombectomy devices

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    Background A direct aspiration first pass thrombectomy (ADAPT) is a fast-growing technique for which a broad catalog of catheters that provide a wide range of aspiration forces can be used. We aimed to characterize different catheters' aspiration performance on stiff clots in an in vitro vascular model. We hypothesized that labeled catheter inner diameter (labeled-ID) is not the only parameter that affects the aspiration force (asp-F) and that thrombus–catheter tip interaction and distensibility also play a major role. Methods We designed an experimental setup consisting of a 3D-printed carotid artery immersed in a water deposit. We measured asp-F and distensibility of catheter tips when performing ADAPT on a stiff clot analog larger than catheter labeled-ID. Correlations between asp-F, catheter ID, and tip distensibility were statistically assessed. Results Experimental asp-F and catheter labeled-ID were correlated (r=0.9601; P<0.01). The relative difference between experimental and theoretical asp-F (obtained by the product of the tip’s section area by the vacuum pressure) correlated with tip’s distensibility (r=0.9050; P<0.01), evidencing that ADAPT performance is highly influenced by catheter tip shape-adaptability to the clot and that the effective ID (eff-ID) may differ from the labeled-ID specified by manufacturers. Eff-ID showed the highest correlation with experimental asp-F (r=0.9944; P<0.01), confirming that eff-ID rather than labeled-ID should be considered to better estimate the device efficiency. Conclusions Catheter tip distensibility can induce a significant impact on ADAPT performance when retrieving a stiff clot larger than the device ID. Our findings might contribute to optimizing thrombectomy strategies and the design of novel aspiration catheters.Peer ReviewedPostprint (published version

    Impact of interhospital transfer vs. direct admission on acute ischemic stroke patients: A subset analysis of the COMPLETE registry

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    Acute ischemic stroke; Aspiration thrombectomy; Interhospital transferIctus isquèmic agut; Trombectomia per aspiració; Trasllat interhospitalariIctus isquémico agudo; Trombectomía por aspiración; Traslado interhospitalarioBackground: Efficacy of thrombectomy treatment in acute ischemic stroke large vessel occlusion (AIS-LVO) patients is time dependent. Direct admission to thrombectomy centers (vs. interhospital transfer) may reduce time to treatment and improve outcomes. In this subset analysis of the COMPLETE registry, we compared outcomes between direct to thrombectomy center (Direct) vs. transfer from another hospital to thrombectomy center (Transfer) in AIS-LVO patients treated with aspiration thrombectomy. Methods: COMPLETE was a prospective, international registry that enrolled patients from July 2018 to October 2019, with a 90-day follow-up period that was completed in January 2020. Imaging findings and safety events were adjudicated by core lab and independent medical reviewers, respectively. Pre-defined primary endpoints included post-procedure angiographic revascularization (mTICI ≥2b), 90-day functional outcome (mRS 0–2), and 90-day all-cause mortality. Planned collections of procedural time metrics and outcomes were used in the present post-hoc analysis to compare outcomes between transfer and direct patient cohorts. Results: Of 650 patients enrolled, 343 were transfer [52.8% female; mean (SD) age, 68.2 (13.9) years], and 307 were direct [55.4% female; 68.5 (14.5) years] admit. Median onset-to-puncture time took longer in the transfer vs. direct cohort (5.65 vs. 3.18 h: 2.33 h difference, respectively; p < 0.001). There was no significant difference in successful revascularization rate, mTICI ≥2b (88.3 and 87.3%), sICH at 24 h (3.8 and 3.9%), median length of hospital stay (7 and 6 days), and 90-day mortality (16.9 and 14.0%) between transfer vs. direct patients, respectively. However, achieving 90-day functional independence was less likely in transfer compared with direct patients (mRS 0–2 was 50.3 vs. 61.7%, p = 0.0056). Conclusions: In the COMPLETE registry, direct to thrombectomy center was associated with significantly shorter onset-to-puncture times, and higher rates of good clinical outcome across different geographies. Additional research should focus on AIS-LVO detection to facilitate direct routing of patients to appropriate treatment centers.This study was funded by Penumbra, Inc (Alameda CA). OZ, JF, and AH were the study's principle investigators and were involved in study design. The sponsor was responsible for database setup, site monitoring, data management, and statistical analysis

    Mechanical thrombectomy with a novel device: initial clinical experience with the ANA thrombectomy device

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    Mechanical thrombectomy; New device; StrokeTrombectomia mecànica; Nou dispositiu; IctusTrombectomía mecánica; Nuevo dispositivo; IctusIntroduction The ANA™ (Anaconda Biomed) thrombectomy system is a novel stroke thrombectomy device comprising a self-expanding funnel designed to reduce clot fragmentation by locally restricting flow while becoming as wide as the lodging artery. Once deployed, ANA allows distal aspiration in combination with a stentretriever (SR) to mobilize the clot into the funnel where it remains copped during extraction. We investigate safety and efficacy of ANA™ in a first-in-man study. Methods Prospective data was collected on 35 consecutive patients treated as first line with ANA™ at a single centre. Outcome measures included per-pass reperfusion scores, symptomatic intracerebral hemorrhage (sICH), NIHSS at day 5, and mRS at 90 days. Results Median NIHSS was 12(9−18). Sites of primary occlusion were: 5 ICA, 15 M1-MCA, 15 M2-MCA. Primary performance endpoint, mTICI 2b-3 within 3 passes without rescue therapy was achieved in 91.4% (n = 32) of patients; rate of complete recanalization (mTICI 2c-3) was 65.7%. First pass complete recanalization rate was 42.9%, and median number of ANA passes 1(IQR: 1−2). In 17.1% (n = 6) rescue treatment was used; median number of rescue passes was 2(1–7), leading to a final mTICI2b-3rate of 94.3% (n = 33). There were no device related serious adverse events, and rate of sICH was 5.7% (n = 2). At 5 days median NIHSS was 1 (IQR 1−6) and 90 days mRS 0−2 was achieved in 60% of patients. Conclusions In this initial clinical experience, the ANA™ device achieved a high rate of complete recanalization with a good safety profile and favourable 90 days clinical outcomes.The study was funded by Anaconda Biomed S.L

    A fully automatic method for vascular tortuosity feature extraction in the supra-aortic region: unraveling possibilities in stroke treatment planning

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    Vascular tortuosity of supra-aortic vessels is widely considered one of the main reasons for failure and delays in endovascular treatment of large vessel occlusion in patients with acute ischemic stroke. Characterization of tortuosity is a challenging task due to the lack of objective, robust and effective analysis tools. We present a fully automatic method for arterial segmentation, vessel labelling and tortuosity feature extraction applied to the supra-aortic region. A sample of 566 computed tomography angiography scans from acute ischemic stroke patients (aged 74.8 ± 12.9, 51.0% females) were used for training, validation and testing of a segmentation module based on a U-Net architecture (162 cases) and a vessel labelling module powered by a graph U-Net (566 cases). Successively, 30 cases were processed for testing of a tortuosity feature extraction module. Measurements obtained through automatic processing were compared to manual annotations from two observers for a thorough validation of the method. The proposed feature extraction method presented similar performance to the inter-rater variability observed in the measurement of 33 geometrical and morphological features of the arterial anatomy in the supra-aortic region. This system will contribute to the development of more complex models to advance the treatment of stroke by adding immediate automation, objectivity, repeatability and robustness to the vascular tortuosity characterization of patients

    Impact of interhospital transfer vs. direct admission on acute ischemic stroke patients: A subset analysis of the COMPLETE registry

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    Background: Efficacy of thrombectomy treatment in acute ischemic stroke large vessel occlusion (AIS-LVO) patients is time dependent. Direct admission to thrombectomy centers (vs. interhospital transfer) may reduce time to treatment and improve outcomes. In this subset analysis of the COMPLETE registry, we compared outcomes between direct to thrombectomy center (Direct) vs. transfer from another hospital to thrombectomy center (Transfer) in AIS-LVO patients treated with aspiration thrombectomy. Methods: COMPLETE was a prospective, international registry that enrolled patients from July 2018 to October 2019, with a 90-day follow-up period that was completed in January 2020. Imaging findings and safety events were adjudicated by core lab and independent medical reviewers, respectively. Pre-defined primary endpoints included post-procedure angiographic revascularization (mTICI ≥2b), 90-day functional outcome (mRS 0-2), and 90-day all-cause mortality. Planned collections of procedural time metrics and outcomes were used in the present post-hoc analysis to compare outcomes between transfer and direct patient cohorts. Results: Of 650 patients enrolled, 343 were transfer [52.8% female; mean (SD) age, 68.2 (13.9) years], and 307 were direct [55.4% female; 68.5 (14.5) years] admit. Median onset-to-puncture time took longer in the transfer vs. direct cohort (5.65 vs. 3.18 h: 2.33 h difference, respectively; p \u3c 0.001). There was no significant difference in successful revascularization rate, mTICI ≥2b (88.3 and 87.3%), sICH at 24 h (3.8 and 3.9%), median length of hospital stay (7 and 6 days), and 90-day mortality (16.9 and 14.0%) between transfer vs. direct patients, respectively. However, achieving 90-day functional independence was less likely in transfer compared with direct patients (mRS 0-2 was 50.3 vs. 61.7%, p = 0.0056). Conclusions: In the COMPLETE registry, direct to thrombectomy center was associated with significantly shorter onset-to-puncture times, and higher rates of good clinical outcome across different geographies. Additional research should focus on AIS-LVO detection to facilitate direct routing of patients to appropriate treatment centers. Clinical trial registration: https://clinicaltrials.gov (Unique identifier: NCT03464565)

    Intrasaccular Flow Disruptor-Assisted Coiling of Intracranial Aneurysms Using the Novel Contour Neurovascular Systems and NEQSTENT: A Single-Center Safety and Feasibility Study

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    Brain aneurysms; Endovascular treatment; Intrasaccular devicesAneurismas cerebrales; Tratamiento endovascular; Dispositivos intrasacularesAneurismes cerebrals; Tractament endovascular; Dispositius intrasacularsBackground: Intrasaccular flow disruptors (IFD) have been introduced in the treatment of intracranial aneurysms (IAs) to overcome the low aneurysm occlusion rate and the high recanalization rate of the coiling technique. Among them, the Contour Neurovascular System (CNS) and the Neqstent (NQS) were designed to reconstruct the aneurysmal neck and both can be used as assisting coiling devices. We aimed to report our preliminary experience with the flow disruptor-assisted coiling (IFD-AC) technique. Methods: We performed a retrospective analysis of prospectively collected data of all patients with IAs treated with the IFD-AC. Results: Between February 2021 and April 2022, we treated 15 IAs with the IFD-AC: 10 ruptured and 5 unruptured. The IFD-AC was successfully performed in 13 cases, with a post-operative RROC 1 in 12 cases (92.3%) and RROC 2 in 1 case (7.7%). There was one ischemic event (6.7%) and no hemorrhagic complications. Twelve patients underwent a mid-term radiologic follow-up: Ten IAs (83.4%) presented an adequate occlusion, while 2 (16.7%) had a recurrence. Conclusions: The IFD-AC, both with the CNS and the NQS, seems a safe technique with promising efficacy profile. The IFD-AC has proved to be safe without antiplatelet therapy in ruptured cases. Further studies are needed to confirm our preliminary results
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