Faster Treatment Times Research Articles

Streamlining Acute Stroke Processes and Data Collection: A Narrative Review

(1) Background: Acute ischemic stroke treatment has been thoroughly studied to identify strategies to reduce treatment times. However, many centers still struggle to achieve fast treatment times. Additionally, studies primarily focus on larger, more advanced centers; yet, smaller centers often face longer treatment times. (2) Objectives: The aim of this study is to analyze the existing literature reviewing stroke treatment processes in primary and comprehensive stroke centers that investigated or reduced treatment times. The articles identified were categorized based on the focus areas and approaches used. (3) Results: Three main categories of improvements were identified in the literature: (1) standardization of processes, (2) resource management, and (3) data collection. Both primary and comprehensive stroke centers were able to reduce treatment times through standardization of the processes. However, challenges such as variations in hospital resources and difficulties incorporating data collection software into workflow were highlighted. Additionally, many strategies to optimize resources and data collection that can benefit primary stroke centers were only conducted in comprehensive stroke centers. (4) Conclusions: Many existing strategies to improve stroke treatment times, such as pre-notification and mass stroke team alerts, have been implemented in both primary and comprehensive stroke centers. However, tools such as simulation training are understudied in primary stroke centers and should be analyzed. Additionally, while data collection and feedback are recognized as crucial for process improvement, challenges persist in integrating consistent data collection methods into clinical workflow. Further development of easy-to-use software tailored to clinician needs can help improve stroke center capabilities to provide feedback and improve treatment processes.

Surface Tuning of Transparent Electrodes with Atmospheric Pressure Plasma for Third Generation Photovoltaics

Transparent semiconductor thin films such as indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) are commonly used in optoelectronic devices due to their favorable properties such as high conductivity and transparency and suitable work function [1]. Their use ranges from light-emitting diodes through flat panel displays up to solar cells. In this context, surface stoichiometry plays a crucial role in influencing the final properties of the final device. Therefore, efficient surface treatment has been a topic in research for years, covering a wide range of approaches from wet and dry treatments. Among these possibilities, plasma treatment remains today the most effective. In several studies [2, 3], atmospheric pressure plasma shown an increase of surface energy, decrease the contamination while enhancing the work function of both ITO and FTO. Low temperature, fast processing times, and no special requirements for working gas are the main advantages of this approach.In this study, the authors compare the effects of cold (<100°C) atmospheric pressure plasma on ITO and FTO after air and nitrogen treatment to provide deeper insight into the interaction of discharge with semiconductive materials during treatment. A coplanar dielectric barrier discharge has been used for the surface modification (more information available in [4]). For this configuration both electrodes lay in one plane, and the discharge occurs on the top of the barrier. Chemical changes in the surface were also evaluated as a function of plasma parameters without any pre-treatment of the substrates. For both studied materials, similar trends were observed at fast treatment times (<60s of plasma exposure). The plasma treatment resulted in a decrease of water contact angle from the initial 90° for ITO to 10° after 30 seconds of exposure. For FTO, the initial angle 60° was lowered to 10° after just 5 seconds of exposure, and complete hydrophilicity was obtained after 30 seconds of plasma treatment. An interesting trend in oxygen concentration measured by XPS was observed for ITO but not FTO samples. From a physical point of view, the interaction with the conductive sample affects the orientation of filaments during the surface modification. Additionally, the results suggest that for small working distances, the physical regime can vary from coplanar to volume discharge as shown in Figure 1. All changes were observed with ICCD imaging (Pi-Max 4, Princeton Instruments). Regarding the physical changes over the surface, the plasma treatment resulted in decreased roughness with no significant effect on conductivity.In conclusion, the results obtained in this study can be utilized in the manufacturing process of microelectronic devices and provide a deeper insight into how the treatment process influences discharge parameters.[1] Armstrong et al. https://doi.org/10.1016/j.tsf.2003.08.067[2] Šimor et al. https://doi.org/10.1063/1.1513185[3] Donley et al. https://doi.org/10.1021/la011101t[3] Chaney et al. https://doi.org/10.1016/S0169-4332(03)00617-2 Figure 1

Abstract WP63: Direct Physician Call to Spoke Reduces Door to Needle Time in a Telestroke Network

Background: Door-to-needle time (DTN) and strategies to reduce DTN are well published, but less is known about specific processes that may contribute to DTN in sites using telestroke. We aimed to reduce potential delays in connecting the telestroke physician with the spoke by eliminating the initial call by telestroke physicians to the call center. Methods: A retrospective analysis examined telestroke patients treated with IV thrombolysis from 06/01/2018 to 03/15/2023 in a 20 spoke network. Telestroke physicians began calling the spoke back directly (instead of calling transfer center to be connected) in July 2022. We compared data and outcomes in the two groups; Prior to Direct Phone (PDP) and After Direct Phone (ADP). Primary outcome analyzed DTN before and after direct connection. Secondary outcome was telestroke page to video times. Primary and secondary outcomes were analyzed using quantile regressions specifying the median, adjusted for confounding variables determined in preliminary analyses. A subgroup analysis was completed in patients transferred for endovascular thrombectomy (EVT) after IVT, to evaluate Door in Door out time (DIDO), using a median regression adjusted for potential confounding variables. Results: There were 580 patients in this study; 469 patients in the PDP group and 111 patients in the ADP group. Patients had a mean age and SD of 69.13 ±15.03 years and a median NIHSS (interquartile range) of 6 (4, 12). After adjusting for potential confounding variables, DTN in the ADP group was 9.22 minutes quicker than in the PDP group, [95% Confidence (CI), 2.07 - 16.36], p = 0.01. Adjusted telestroke page to video times were 2.60 minutes quicker in the ADP compared to the PDP group, [95%CI, 0.01 - 5.20], p = 0.05. There were 137 patients (121 in PDP; 24 in ADP) in the subgroup analysis. There were similar DIDO times in both groups; 1.06 minutes faster in the ADP group, but not statistically significant [95%CI, -14.56, 16.68], p = 0.89. Conclusion: Eliminating one step in the telestroke process by connecting directly to the telestroke site resulted in faster treatment times. Removing the call center from the initial phone call did not delay DIDO times but the downstream effect from removing the step was likely minimized in patients transferred for EVT.

Higher Procedural Volumes are Associated with Faster Treatment Times, Better Functional Outcomes, and Lower Mortality in Patients Undergoing Endovascular Treatment for Acute Ischemic Stroke.

We aimed to characterize the association of hospital procedural volumes with outcomes among acute ischemic stroke (AIS) patients undergoing endovascular therapy (EVT). This was a retrospective, observational cohort study using data prospectively collected from January 1, 2016, to December 31, 2019, in the Get With The Guidelines-Stroke registry. Participants were derived from a cohort of 60,727 AIS patients treated with EVT within 24 hours at 626 hospitals. The primary cohort excluded patients with pretreatment NIHSS <6, onset-to-treatment time >6 hours, and inter-hospital transfers. There were two secondary cohorts: (1) EVT metrics cohort: excluded patients with missing data on time from door-to-arterial-puncture; (2) Intravenous thrombolysis (IVT) metrics cohort: only included patients receiving IVT ≤4.5 hours of onset. The primary cohort (mean±SD age, 70.7 ±14.8 years; 51.2% female; median [IQR] baseline NIHSS 18.0 [13-22]; IVT use, 70.2%) comprised 21,209 patients across 595 hospitals. The EVT metrics cohort and IVT metrics cohort comprised 47,262 and 16,889 patients across 408 and 601 hospitals, respectively. Higher procedural volumes were significantly associated with higher odds (expressed as adjusted odds ratio [95% confidence interval] for every 10-case-increase in volume) of discharge to home (1.03[1.02-1.04]), functional independence at discharge (1.02[1.01-1.04]), and lower rates of in-hospital mortality (0.96[0.95-0.98]). All secondary measures were also associated with procedural volumes. Among AIS patients primarily presenting to EVT capable hospitals (excluding those transferred from one facility to another and those suffering in-hospital strokes), EVT at hospitals with higher procedural volumes was associated with faster treatment times, better discharge outcomes, and lower rates of in-hospital mortality. This article is protected by copyright. All rights reserved.

Photoluminescence Investigations and Band Gap Engineering in Environment Friendly ZnO Nanorods: Enhanced Water Treatment Application and Defect Model.

The inadvertent discharge of industrial effluents, mainly textile, contributes to the complex contamination load in water bodies. Textile dyes are the critical effluents and recalcitrant to traditional remediation procedures. Therefore, energy viable and environment friendly solutions are needed. In this study, we have synthesized zinc oxide nanorods (NRs) at various temperatures using modified thermal decomposition and evaluated its photocatalytic activities. Field effect scanning electron microscopy has confirmed rod-like morphology till TS = 500 °C and spherical morphology from TS = 600 °C onward. Photoluminescence spectra have shown a prominent defect peak in the synthesized ZnO, except for the NRs synthesized at 300 °C. Synthesized ZnO NRs and NPs have been employed to degrade crystal violet (CV) and congo red (CR) dyes. ZnO NRs have shown impressive photocatalytic performance with faster treatment time as compared to the earlier reports. Synthesis parameters are well correlated with the observed high efficiency and the band gap tailoring. Based on our findings, for the first time, we have proposed (i) defect model correlating synthesis parameters with defect states, (ii) systematic correlation of defect states with photocatalytic efficiency, and (iii) ZnO nanorods synthesized at 300 °C via an improved synthesis method as a promising photocatalytic solution to degrade the CV and CR dyes in contaminated water.

Comparing Traditional and “In-Motion” Intense Pulsed Light Techniques for Hair Removal: A Split Study

Background and Objectives: Hair removal is a common aesthetic concern for patients referred to dermatologists and aesthetic physicians. Lasers and lights are one of the mainstays in the management of this condition. Among these devices, intense pulsed lights (IPLs) are broadly used in order to reduce the number and width of the hair present. Currently used techniques are associated with a high risk of side effects, such as hyper or hypopigmentation. Materials and Methods: Thirty patients seeking hair removal in one or more body areas with skin phototypes 1 to 4 were recruited to perform this study. All areas to be treated were divided into two equal regions; one side was treated with the standard IPL hair removal procedure, while the other was treated with a new “in-motion” IPL technology. Results and hair removal rates were evaluated six months after the last treatment. Results: Out of the 30 patients treated, all patients experienced hair reduction. No statistically significant difference in hair removal was noted among the two sides. A statistically significant reduction in pain during the procedure was observed in the side treated with the “in-motion” technique. Conclusions: Traditional and “in-motion” IPL techniques have similar results in hair removal; the “in-motion” technology seems to guarantee a better safety profile than the traditional technique, as well as maintains the same results over time and a faster treatment time. A more extensive clinical study will be necessary to confirm our study’s results.

Simulation-based team-training in acute stroke: Is it safe to speed up?

In acute ischemic stroke (AIS), rapid treatment with intravenous thrombolysis (IVT) is crucial for good clinical outcome. Weekly simulation-based team-training of the stroke treatment team was implemented, resulting in faster treatment times. The aim of this study was to assess whether this time reduction led to a higher proportion of stroke mimics (SMs) among patients who received IVT for presumed AIS, and whether these SM patients were harmed by intracranial hemorrhage (ICH). All suspected AIS patients treated with IVT between January 1, 2015 and December 31, 2020 were prospectively registered. In 2017, weekly in situ simulation-based team-training involving the whole stroke treatment team was introduced. To analyze possible unintended effects of simulation training, the proportion of SMs among patients who received IVT for presumed AIS were identified by clinical and radiological evaluation. Additionally, we identified the extent of symptomatic ICH (sICH) in IVT-treated SM patients. From 2015 to 2020, 959 patients were treated with IVT for symptoms of AIS. After introduction of simulation training, the proportion of patients treated with IVT who were later diagnosed as SMs increased significantly (15.9% vs. 24.4%, p=.003). There were no ICH complications in the SM patients treated before, whereas two SM patients suffered from asymptomatic ICH after introduction of simulation training (p=1.0). When subgrouping SMs into prespecified categories, only the group diagnosed with peripheral vertigo increased significantly (2.5% vs. 8.6%, p<.001). Simulation training of the acute stroke treatment team was associated with an increase in the proportion of patients treated with IVT for a suspected AIS who were later diagnosed with peripheral vertigo. The proportion of other SM groups among IVT-treated patients did not change significantly. No sICH was detected in IVT-treated SM patients.

Analysis of Key Clinical Variables and Radiological Manifestations Associated with the Treatment Response of Patients with Brain Metastases to Stereotactic Radiosurgery.

Background: Stereotactic radiosurgery (SRS) is considered a promising treatment for brain metastases (BM) with better healing efficacy, relatively faster treatment time, and lower neurotoxicity, which can achieve local control rates above 70%. Although SRS improves the local control of BM, this may not translate into improvements in survival time. Thus, screening out the key factors influencing the treatment response to SRS, instead of the survival time following SRS, might be of more significance. This may assist doctors when making adjustments to treatment strategies for patients with BM. Methods: This is a retrospective review of 696 patients with BM who were treated with SRS at Huashan Hospital, Fudan University between June 2015 and February 2020. According to the patients’ treatment response to SRS, the patients were divided into an improved group (IG) and a progressive group (PG). The clinical data and magnetic resonance imaging (MRI) performed pre- and post-treatment were collected for the two groups. Five clinical variables (gender, age, Karnofsky performance status (KPS), primary tumor type, and extracranial lesion control) and seven radiological manifestations (location, number, volume, maximum diameter, edema index (EI), diffusion weighted imaging (DWI) sequence signal, and enhanced pattern) were selected and compared. A stepwise regression analysis was performed in order to obtain the best prediction effect of a group of variables and their regression coefficients, and finally to build an SRS treatment response scoring model based on the coefficients. The performance of the model was evaluated by calculating the AUC and performing the Hosmer–Lemeshow test. Results: A total of 323 patients were enrolled in the study based on the inclusion and exclusion criteria, including 209 patients in the IG and 114 patients in the PG. In the Chi-square test and t-test analysis, the significant p values of KPS, extracranial lesion control, volume, and EI were less than 0.05. Moreover, the cut-off values for volume and EI were 1801.145 mm3 and 3.835, respectively. The scoring model that was based on multivariate logistic regression coefficients performed better, achieving AUCs of 0.755 ± 0.062 and 0.780 ± 0.061 for the internal validation and validation cohorts, with p values of 0.168 and 0.073 for the Hosmer–Lemeshow test. Conclusions: KPS, extracranial lesion control, tumor volume, and EI had a certain correlation with the treatment response to SRS. Scoring models that are based on these variables can accurately predict the treatment response of patients with BM to SRS, thereby assisting doctors to make an appropriate first treatment strategy for patients with BM to a certain degree.

Association Between Endovascular Therapy Time to Treatment and Outcomes in Patients With Basilar Artery Occlusion.

Basilar artery occlusion (BAO) is a devastating condition without definitive evidence to guide treatment. Whereas the association between faster treatment times with endovascular therapy (EVT) and better outcomes in anterior circulation is well established, whether this relationship exists for patients with BAO is not well delineated. We used individual-level patient data from the Get With The Guidelines-Stroke nationwide US registry prospectively collected from January 2015 to December 2019. We identified individuals with BAO treated with EVT within 24 hours of symptom onset. The primary outcomes examined were in-hospital mortality, discharge home, ambulatory at discharge, independent at discharge (modified Rankin Scale score 0 to 2), substantial reperfusion (modified Thrombolysis in Cerebral Infarction score 2b or 3), and symptomatic intracranial hemorrhage. Using logistic regression models, we evaluated the association between time from symptom onset to treatment with EVT and outcomes. Among 3015 patients with BAO treated with EVT, the mean age was 65.9 years, 38.8% were women, and the median National Institutes of Health Stroke Scale score at presentation was 17 (interquartile range, 8-26). Median onset to EVT time was 406 minutes (interquartile range, 252-688). From 2015 to 2019, there was an overall increase in the median onset to EVT times (380-411 minutes; P=0.016) but no significant change in the proportion of patients treated within 6 hours of symptom onset (48.4%-44.0%; P=0.17). After risk adjustment for patient and hospital-level factors, there were significantly lower odds of in-hospital mortality (adjusted odds ratio [aOR], 0.55 [95% CI, 0.45-0.68]) and symptomatic intracranial hemorrhage (aOR, 0.52 [95% CI, 0.32-0.84]) and significantly higher odds of ambulation at discharge (aOR, 1.72 [95% CI, 1.37-2.16]), discharge home (aOR, 2.19 [95% CI, 1.73-2.77]), and independence at discharge (aOR, 2.21 [95% CI, 1.66-2.95]) when onset to EVT time was ≤6 hours compared with >6 hours. The fastest decay in good outcomes per hour occurred within 6 hours of symptom onset. Among patients receiving EVT for BAO, faster treatment from symptom onset was associated with improved outcomes. These findings support efforts to achieve rapid treatment with EVT for patients with BAO.

Abstract No. 126 Directional microwave ablation in bone: modeling and ex vivo evaluation

Bone is the third most common site of metastatic spread; bladder, breast, kidney, lung, melanoma, prostate, thyroid, and uterine cancer all commonly metastasize to bone and often bone can be the first site attacked. Microwave ablation (MWA) offers a minimally invasive approach for palliative treatment of bone metastases, as well as primary bone tumors. Compared to other ablative energy modalities, microwaves can radiate through low impedance tissue, such as bone, while providing a fast treatment time. However, there are few published studies describing biophysics of MWA in bone. This study investigates the use of an experimental directional MWA (DMWA) applicator, previously optimized for liver ablation, for treatment of metastatic tumors in vertebral bodies. An experimental 14-gauge DMWA applicator previously characterized in ex vivo and in vivo liver tissues was used in this study. A 3D finite element method solver (COMSOL Multiphysics v5.5) was used to simulate the electromagnetic radiation pattern and subsequent heat transfer of one and two DMWA applicators in an anatomically representative model. Temperature dependent tissue biophysical properties were employed for cortical bone, cancellous bone, cartilage, spinal cord, tumor, and muscle. Ex vivo microwave ablations were performed in lumbar and thoracic vertebrae excised from domestic swine within 3 h post-mortem. The DMWA applicator was inserted through the cortex with its backside adjacent to the dorsal surface of the vertebral body aiming ventrally. Fiber optic temperature sensors were placed on the ventral surface of the spinal canal and in the center of the vertebral body. The vertebrae were cross-sectioned for measurement of the visible ablation zone. Simulations of two DMWA applicators (30 W each, 300 s) in a vertebral body with a 2 cm tumor having biophysical properties mimicking muscle tissue yielded simulated ablation zones 2.5 cm long × 1.5 cm tall × 2.0 cm wide with a near-rectangular shape (as assessed by the 55°C isotherm). Simulations of two DMWA applicators (30 W each, 300 s) in a vertebral body with a 2 cm tumor having biophysical properties mimicking cortical bone yielded simulated ablation zones 2.5 cm long × 1.5 cm tall × 1.5 cm wide in the center and 2.0 cm wide on the sides with a butterfly-type shape. The 45°C isotherm did not extend to the spinal cord domain in either simulation. Ex vivo DMWA experiments are in progress and will be presented at the meeting. DMWA offers the potential for targeted treatment of metastatic and primary tumors in vertebral bodies and other bone sites.

Abstract P13: Faster Treatment Speed is Not Associated With Bleeds: Intravenous Alteplase Treatment in the Ultra-Early Time Window is Safe

Previous studies have shown that faster Door to Needle (DTN) treatment times are associated with better outcomes for acute ischemic stroke patients. With the continued push for faster times, we aimed to determine if DTN treatment times in the 30- vs 45-minute time window yielded statistically significant differences in outcomes or complications. Data obtained from a multi-state stroke registry included acute ischemic stroke patients ≥18 years of age discharged between January 2017 and April 2020, and treated with IV alteplase with DTN times between 25-30 or 40-45 minutes. Outcomes were 90-day Modified Rankin Score (mRS) (0-2 vs 3-6), discharge disposition [home or inpatient rehabilitation facility (IRF) vs other location], complications (any treatment-related complication vs none), and hospital length of stay (LOS). Patients with a documented reason for delay or who received thrombectomy were excluded. Outcomes of patients with 25- to 30-minute DTN times were compared to those with 40- to 45-minute DTN times using generalized linear models and multiple linear regression, adjusting for admission NIHSS, age, gender, race/ethnicity, and medical history. Compared to the 20-25 minute group, patients treated in the 40-45 minute window had higher odds of a documented 90-day mRS of 3 or more (Adjusted Odds Ratio (AOR)=1.19, p=0.253, n=201 ) and treatment-related complication (AOR=1.35, p=0.569) and lower odds of discharge to home or IRF (AOR=0.846, p=0.359). There was little difference in LOS (β=-0.008, p=0.847). None of the outcomes reached statistical significance. Administering alteplase in the 25- to 30-minute window is safe and did not result in an increase in bleeding complications. Although faster treatment times trended toward better outcomes, there was no statistically significant difference between the 25-30 and 40-45 minute DTN treatment times.

Comparison of the Effectiveness of the Chemosurgery and Cryosurgery for the Treatment of Patients with Condyloma Acuminatum

Background: Condyloma acuminatum (CA) is one of the most common sexually transmitted infections. Several therapeutic modalities that can be used are chemosurgery with trichloroacetic acid and cryosurgery with liquid nitrogen. Recurrence in CA often occurs, so selecting the right therapeutic modality and eliminating the lesion also prevents recurrence. This study aimed to compare the effectiveness of chemosurgery and cryosurgery therapy in patients with CA who are treated at Dr. Moewardi Hospital, Surakarta. Subjects and Method: A retrospective cross-sectional study was conducted at the Dermatology and Venereology Polyclinic, Dr. Moewardi Hospital, Surakarta, from January 1, 2018, to December 31, 2020. The study subjects were 78 patients diagnosed with CA based on ICD-10 criteria, while chemosurgery and cryosurgery procedures were based on ICD-9. The dependent variable was healing time in weeks. The independent variables were chemosurgery and cryosurgery therapy. The data came from the patient's medical record. Data were analyzed using an independent t-test. Results: Based on univariate analysis, most patients were male (67.9%), and the age group was 20-29 years (51.28%). Most of the CA patients work as private employees (46.15%). The most sexual orientation was heterosexual (53.8%), the most common site of lesions was genital (47.4%), and 52.6% were coinfected with HIV. Most CA patients received chemosurgery (70.5%). Bivariate analysis showed that chemosurgery therapy provided faster clinical improvement (Mean= 23.34; SD= 26.45) than cryosurgery therapy (Mean= 28.69; SD= 19.84), and the difference was statistically significant (p= 0.037). Conclusion: Treatment of CA using chemosurgery provides clinical improvement faster than cryosurgery, so that faster treatment time can reduce treatment costs and improve the patient's quality of life. Keywords: chemosurgery, cryosurgery, HPV, condyloma acuminatum Correspondence: Prasetyadi Mawardi. Department of Dermatology and Venereology, Faculty of Medicine of Universitas Sebelas Maret/ Dr. Moewardi Hospital, Surakarta, Central Java, Indonesia. Email: prasetyadimawardi@gmail.com/ prasetyadi_m@staff.uns.ac.id. Mobile: +6281229750211. Indonesian Journal of Medicine (2021), 06(03): 290-297 https://doi.­org/10.26911/the­ijmed.­2021.06.03.06

Peppermint flavor oil in fluoride varnishes enhances fluoride release

Background: Fluoride varnish (FV) is a common dental health treatment for the prevention of early childhood caries. Application of FV with a flavoring agent promotes comfort and acceptance by patients, especially children, and facilitates an effective treatment time. Objective: Flavored FV with a pleasant flavor should allow a faster treatment time, especially with children. The aim of this research was to study basic FV formulations containing different flavors of essential oils (LorAnn) and variations in the concentrations of flavor oils to determine the optimum formulation to enhance the in vitro fluoride release time. Methods: The independent variables were the flavors (apple, melon, and peppermint) and the concentrations (1, 1.5, 2, or 2.5%) of the flavor that gave the best fluoride release (peppermint). The amounts of fluoride ions released in 6 h into deionized water were assessed at 37°C using an ion-selective electrode with the addition of fluoride total ionic strength adjustment buffer solution to strengthen the ion reading. The cumulative ion release was analyzed for normality and equality of variance, and the means were compared using a general linear model test and Statistical Package for Social Sciences version 23.0 software. The significance level was set at α = 0.05. Results: At the same concentration of 2% for the apple, melon, and peppermint flavors, the peppermint formulation gave the best fluoride release, at 173.22 mg/L. A peppermint oil concentration of 2.5% showed the highest fluoride ion release, at 178.95 mg/L. Conclusions: The addition of peppermint flavor oil at a concentration range of 1—2.5% revealed an increasing release of fluoride ions with an increasing peppermint oil concentration. Further investigations are still needed using artificial saliva to replicate actual conditions in the oral cavity.

Liquid Nitrogen-Based Cryoablation in In Vivo Porcine Tissue: A Pilot Study.

Introduction:Liquid nitrogen-based cryoablation induces freezing evenly throughout the probe tip surface, resulting in larger ablation volumes and faster treatment times. The purpose of this preliminary investigation is to determine the efficacy of the liquid nitrogen-based Visica2 Cryoablation System (Sanarus Technologies, Pleasanton, CA) in in vivo porcine kidney, liver, and fibro-fatty tissue. Methods:Ablations were performed under ultrasound guidance in 4 Yorkshire pigs. The target lesion cross-section width (W) and depth (D) were 1 cm for liver (n=8), kidney (n=4), and head-neck (n=5) and 2 cm for kidney (n=4). Expected axial length (L) of the resulting lesion is approximately 4 cm. After three-day survival, the ablated tissue was harvested and histologically analysed. The mean width and depth were compared with the target diameter using a one-sample t-test. Results:All animals survived the procedure. For the 1 cm target, mean dimensions (L x W x D) were 3.8±1.5 x 1.7±0.3 x 1.7±0.7 for liver, 3.0±0.5 x 2.0±0.4 x 1.7±0.6 for kidney, and 3.3±0.8 x 1.8±0.4 x 1.8±0.4 for head-neck. Mean width and depth were significantly greater than desired dimension. For the 2 cm target, mean dimensions were 3.2±0.5 x 3.1±0.8 x 1.9±0.7. Mean width and depth were not significantly different to desired target. Conclusion:Our preliminary results show that the Visica2 liquid nitrogen-based cryoablation system can efficiently and reproducibly create ablation volumes in liver, kidney, and fibro-fatty tissue within 4 minutes and 12 minutes for 1cm and 2cm targeted diameters, respectively. Further investigation is necessary to determine the optimal freeze-thaw-freeze protocol for larger ablation volumes.

Abstract TP246: Refining Hyperacute MRI Protocols to Increase Patient Eligibility for IV tPA

Introduction: Hyperacute MRI (hMRI) increases the number of patients eligible for IV tPA in: (1) patients initially suspected to be stroke mimics (SM) and (2) patients with wake-up or unwitnessed stroke onset (WU-UW). Performing hMRI in a time-frame to enable tPA delivery is challenging for many centers; thus, we evaluated which factors were associated with delays in hMRI and hMRI-related tPA treatment at our institution since publication of the WAKE-UP stroke trial in August 2018. Methods: We analyzed 1-year of prospectively collected hMRI data performed between 07.01.2018 to 06.30.2019. We divided the year into three 4-month epochs; the 1 st epoch was before and the 2 nd and 3 rd epochs were after implementing the Wake-up protocol for WU-UW stroke presentations as a new indication to our streamlined hMRI protocol. We compared baseline variables, hMRI indication, hMRI-related tPA utilization, and time metrics for completing hMRI between the 2 nd and 3 rd epochs. We also evaluated discharge outcomes and safety of tPA treatment in this hMRI cohort. Results: Across the 3 epochs, 84 patients underwent hMRI (n=10 vs. 37 vs. 37, respectively), of whom 13 were treated with IV tPA. hMRI-related tPA utilization increased in epochs 2 vs 3 after initiation of the Wake-Up protocol: 8.1% (epoch 2) vs. 21.6% (epoch 3), and number-needed-to-MRI for one tPA treatment dropped from 12.3 to 4.6. In epochs 2 vs. 3, MRI order-to-scan time decreased (28 vs 23 minutes, P=0.039), indicative of process improvement over time. Across all epochs, hMRI indication of WU-UW (vs. SM) was associated with shorter door-to-hMRI completion (68 vs. 83.5 minutes, P=0.041) and shorter door-to-needle time (76 vs. 118 minutes; P=0.030), whereas age, NIHSS, and sex were not associated with hMRI efficiency. None of the 13 patients treated with IV tPA developed symptomatic ICH and 92% were discharged to home or inpatient rehabilitation. Conclusion: In the final epoch, &lt; 5 MRIs were performed for one tPA treatment, suggesting that a hMRI protocol may improve with time and increased utilization, justifying the use of hMRI to increase patient eligibility for IV tPA. WU-UW stroke indications for hMRI may predict shorter hMRI process and faster treatment times.

Abstract WP106: Redefined Measure of Early Neurological Improvement Shows Treatment Benefit of Intravenous Tissue Plasminogen Activator Treatment in NINDS Rt-PA Acute Stroke Trial at 24 Hours

Background and Purpose: The first of the 2 NINDS Stroke Study trials did not show a significant increase in early neurological improvement (ENI), defined as NIHSS improvement by ≥ 4, with alteplase treatment. We hypothesized that ENI defined as a percentage change in NIHSS (percent change NIHSS) at 24 hours is superior to other definitions in predicting 3-month functional outcomes and using this definition there would be treatment benefit of alteplase over placebo at 24 hours. Methods: We analyzed the NINDS rt-PA Stroke Study (Parts 1 and 2) trial data. Percent change NIHSS was defined as [(admission NIHSS score–24-hour NIHSS score)x100/admission NIHSS score] and delta NIHSS as (admission NIHSS score–24-hour NIHSS score). We compared ENI using these definitions between alteplase vs. placebo patients. We also used receiver operating characteristic (ROC) curve to determine the predictive association of ENI with excellent 3-month functional outcomes [Barthel Index (BI) score 95 – 100 and modified Rankin scale (mRS) 0-1], good 3-month functional outcome (mRS 0-2) and 3-month infarct volume. Results: There was a significantly greater improvement in the 24-hour median percent change NIHSS among patients treated with alteplase compared to the placebo group (28% vs. 15%, p = 0.045) but not median delta NIHSS (3 vs. 2, p = 0.471). ROC curve comparison showed that percent change NIHSS (ROC percent ) was better than delta NIHSS (ROC delta ) and admission NIHSS (ROC admission ) with regards to excellent 3-month BI (ROC percent 0.83, ROC delta 0.76, ROS admission 0.75), excellent 3-month mRS (ROC percent 0.83, ROC delta 0.74, ROS admission 0.78), and good 3-month mRS (ROC percent 0.83, ROC delta 0.76, ROS admission 0.78). Percentage change had a stronger association with 90-day infarct volume than delta NIHSS score and both delta NIHSS and percent change in NIHSS were more pronounced with faster treatment times. Conclusion: In the NINDS rt-PA trial, alteplase was associated with a significant percent change improvement in NIHSS at 24 hours. Percent change in NIHSS may be a better surrogate marker of thrombolytic activity and 3-month outcomes.

Histotripsy: The Next Generation of High-Intensity Focused Ultrasound for Focal Prostate Cancer Therapy.

This article reviews the most current methods and technological aspects of high-intensity focused ultrasound (HIFU), which is termed histotripsy. The rationale for focal therapy for prostate carcinoma rather than prostatectomy, which is being used extensively throughout Europe and Asia, is presented, and an argument for why HIFU is the modality of choice for primary therapy and recurrent disease is offered. The article presents a review of the technical advances including higher ultrasound beam energy than current thermal HIFU which allows for more accurate tissue targeting, less collateral tissue damage, and faster treatment times. Finally, the article presents a discussion about the advantage of ultrasound guidance for histotripsy in preference to magnetic resonance imaging guidance primarily based on cost, ease of application, and portability.

Abstract TP114: Younger Age and Diagnosis of Schizophrenia Increase Door to Needle Times in Acute Ischemic Stroke Patients

Introduction: Faster treatment time for acute ischemic stroke is associated with better outcome. We hypothesized that patient factors such as young age, female sex, premorbid mental health (depression, anxiety, schizophrenia, bipolar) or other conditions (fibromyalgia, chronic pain), may confound making the diagnosis of stroke and thus delay door to needle (DTN) time. Methods: Consecutive patients who received intravenous tPA in our comprehensive stroke center emergency department between January 2015 and June 2018 were reviewed regardless of discharge diagnosis. The primary outcome was DTN time, and secondary outcomes were door to CT imaging (DTI) time and CT read to needle time. Univariate analyses were done using parametric and non-parametric tests and linear regression model was developed with variables with p values &lt;0.15. Results: A total of 225 patients (mean age 63.7 ±15.5 y, 48% women, 67% white, 32% African American, 1.8% other) were identified. Mean DTN was 63 minutes. Patients &lt; 60 y had a mean DTN time of 67.2 minutes vs 60.9 minutes in those &gt; age 60 y (p=0.093). Age &lt;60 was associated with increased mean DTI time (28.6 minutes vs 21.6 minutes in patients &gt; 60; p=0.0068; mean difference of 7 minutes, 95%CI of 2.0, 12.1). There was no significant difference in CT to needle time by age (p=0.77). A known mental health diagnosis or other confounding condition was present in 37%. Four of 225 (1.7%) had schizophrenia, with median DTN time of 91 vs 56 minutes in those without (p=.14). Linear multivariate regression model showed that younger age (p=0.018) and schizophrenia (p=0.009) were independently associated with longer DTN times. Conclusion: Longer DTI times were associated with age less than 60, and longer DTN times were associated with younger age and presence of schizophrenia. Recognition of younger age and schizophrenia by clinicians as confounders could help reduce stroke treatment times.

Abstract TP480: Standardizing Inpatient Stroke Alert Processes Yields Faster Treatment Times in Inpatient Strokes

Background: In-hospital strokes account for 6.5%-15% of all strokes. Efficiently managing inpatient stroke alerts is a resource-intensive process involving multidisciplinary teams. Standardized emergency department (ED) stroke protocols have been shown to decrease time from stroke alert (SA) activation to neuroimaging and treatment. At our institution, stroke patients arriving to the ED were evaluated and treated faster than inpatient (IP) strokes, highlighting the need for an improved IP SA process to meet work flow benchmarks established by the American Stroke Association. Purpose: Standardizing the IP SA process will decrease time to CT imaging and neurological evaluation, reducing SA activation to treatment times for IP strokes. Methods: A revised in-hospital SA protocol was implemented 8/2016 to prioritize early neurology notification and CT imaging. A total of 332 inpatient SA cases from 1/2013-6/2018 were analyzed for: SA activation to neurology contact, SA activation to CT image scout film time, SA activation to thrombolytic (tPA) administration and/or groin puncture time in cases where a mechanical thrombectomy was performed. Results: Analysis showed significant improvements to all of the outcome measures: 35% improvement in IP SA activation to CT imaging start time (N= 167 prior to protocol revision; N=165 after protocol revision), 36% improvement in SA activation to neurology contact time, 59% improvement in SA to tPA administration time (N=7 prior to protocol revision; N=11 after protocol revision), and a 10% improvement in SA to groin puncture time for thrombectomy cases (N=6 cases prior to protocol revision; N=6 after protocol revision). A 36% increase in IP tPA administrations might be attributed to rapid consideration of eligibility within the treatment window. Conclusions: Standardizing IP SA processes to remove inefficiencies optimizes work flow across all phases of evaluation and leads to faster treatment times and increased treatment rates. These findings may serve as the basis for large-scale multicenter studies to further validate effective protocols’ impact on patient outcomes.

Abstract WMP95: Drip and Ship vs. Mothership: Conditional Probability Modelling for Patients With Suspected Large Vessel Occlusion

Introduction: For patients with suspected large vessel occlusion (LVO) stroke should we bypass alteplase treatment at Primary Stroke Centres (PSC) in favor of endovascular therapy (EVT) at Comprehensive Stroke Centres (CSC) (mothership) or transport the patient to the PSC for alteplase and then transfer to the CSC for EVT (drip and ship)? This is complicated by the inability to definitively diagnose LVO stroke without imaging. Methods: The efficacy decay of alteplase and EVT over time and the accuracy of the Los Angeles Motor Scale (LAMS) LVO screening tool were combined with various treatment times to predict the probability of good outcome (mRS 0 - 1 at 90 days) for both transport strategies for patients with LAMS ≥4. Results: The results are shown in the Figure. If the patient is closest to the CSC mothership is always superior. If treatment is fast at both centres drip and ship is superior if the centres are far apart and the patient must travel past a PSC to get to a CSC, otherwise the strategies are equivalent (Panel A). Slow treatment at the PSC increases the area where mothership is superior and eliminates drip and ship unless the time from onset to alteplase administration exceeds 4.5 hours in the mothership scenario (Panel B). Slow treatment at both centres decreases the mothership area and expands the drip and ship area (Panel C). Conclusions: Due to the uncertainty in patient diagnosis both transport options are equivalent in most scenarios. A triaging tool with greater positive predictive value would increase the size of the mothership areas. However, even with diagnosis uncertainty the importance of fast treatment times is illustrated.