Abstract WP294: In Search of Greater Efficiencies: Implementation of Computed Tomography Angiography in a Telestroke Network Improves Triage for Both Primary and Comprehensive Stroke Centers

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Andrew T Yu ◽  
Robert W Regenhardt ◽  
Cynthia Whitney ◽  
Lee Schwamm ◽  
Anand Viswanathan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Computed Tomography Angiography ◽  
System Of Care ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Large Vessel Occlusion ◽  
Vessel Occlusion ◽  
Endovascular Thrombectomy ◽  
The Impact ◽  
Repeat Imaging

Introduction: Telestroke (TS) networks provide an important function in community hospitals by supporting thrombolytic use and screening for patients with large vessel occlusion (LVO) who may be eligible for endovascular thrombectomy (EVT). The expansion of treatment to 24 hours from last known well has dramatically increased the pool of patients to screen. Idealized triage processes within TS networks remain uncertain. We sought to characterize the impact of the implementation of a routine spoke hospital (SH) CTA protocol in our integrated TS network. Methods: We introduced protocol-driven CTA process at 25 SH in November 2017. We retrospectively identified patients who presented to a SH with an NIHSS ≥ 6 between 3/1/2016-3/1/2017 (pre-CTA) and 3/1/2018-3/1/2019 (post-CTA). We characterized baseline demographics, transfer patterns, and rates of CTA utilization, LVO, and EVT. Differences were assessed using Wilcoxon rank-sum for continuous variables and χ2 tests for categorical variables. Results: There were 167 patients pre-CTA and 207 post-CTA. The rate of CTA at SHs increased from 13% to 70% (p<0.001). Despite increased screening of patients >4.5 hr from last known well time, the rates of transfer out of SHs did not increase (56% vs 54%, p=0.83). The rate of transfer to our CSC for EVT increased non-significantly (26% vs 35%, p=0.12) but the proportion of patients transferred >4.5 hr increased ~5-fold (7% vs 34%, p<0.001) with a decrease in need for repeat imaging at our CSC (94% vs 66%, p<0.001). The overall rate of EVT performed on patients transferred for possible EVT more than doubled (22% to 47%, p=0.011). Conclusions: Implementation of a CTA protocol at SHs in our TS network was feasible, and effective in improving the efficiency of interhospital triage of candidates for EVT. In the era of late-window EVT, introducing CTA into PSC enhances the stroke system of care and keeps care local whenever possible. Replication of these findings in other TS networks is needed.

scholarly journals Mobile Stroke Unit Computed Tomography Angiography Substantially Shortens Door-to-Puncture Time

Stroke ◽  
2020 ◽  
Vol 51 (5) ◽  
pp. 1613-1615 ◽  
Author(s):  
Alexandra L. Czap ◽  
Noopur Singh ◽  
Ritvij Bowry ◽  
Amanda Jagolino-Cole ◽  
Stephanie A. Parker ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Computed Tomography Angiography ◽  
Stroke Unit ◽  
Interquartile Range ◽  
National Institutes Of Health ◽  
Unique Identifier ◽  
Vessel Occlusion ◽  
Endovascular Thrombectomy ◽  
Unit Management ◽  
Mobile Stroke Unit

Background and Purpose— Endovascular thrombectomy (ET) door-to-puncture time (DTPT) is a modifiable metric. One of the most important, yet time-consuming steps, is documentation of large vessel occlusion by computed tomography angiography (CTA). We hypothesized that obtaining CTA on board a Mobile Stroke Unit and direct alert of the ET team shortens DTPT by over 30 minutes. Methods— We compared DTPT between patients having CTA onboard the Mobile Stroke Unit then subsequent ET from September 2018 to November 2019 and patients in Mobile Stroke Unit from August 2014 to August 2018, when onboard CTA was not yet being used. We also correlated DTPT with change in National Institutes of Health Stroke Scale between baseline and 24 hours. Results— Median DTPT was 53.5 (95% CI, 35–67) minutes shorter with onboard CTA and direct ET team notification: 41 minutes (interquartile range, 30.0–63.5) versus 94.5 minutes (interquartile range, 69.8–117.3; P <0.001). Median on-scene time was 31.5 minutes (interquartile range, 28.8–35.5) versus 27.0 minutes (interquartile range, 23.0–31.0) ( P <0.001). Shorter DTPT correlated with greater improvement of National Institutes of Health Stroke Scale (correlation=−0.2, P =0.07). Conclusions— Prehospital Mobile Stroke Unit management including on-board CTA and ET team alert substantially shortens DTPT. Registration— URL: https://clinicaltrials.gov ; Unique identifier: NCT02190500.

scholarly journals Mechanical Thrombectomy of the Fetal Posterior Cerebral Artery

2021 ◽  
Author(s):  
Mohamad Abdalkader ◽  
Anurag Sahoo ◽  
Adam A. Dmytriw ◽  
Waleed Brinjikji ◽  
Guilherme Dabus ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Endovascular Treatment ◽  
Cerebral Artery ◽  
Computed Tomography Angiography ◽  
Mechanical Thrombectomy ◽  
Posterior Cerebral Artery ◽  
Large Vessel ◽  
Large Vessel Occlusion ◽  
Anterior Circulation ◽  
Vessel Occlusion

Abstract BACKGROUND Fetal posterior cerebral artery (FPCA) occlusion is a rare but potentially disabling cause of stroke. While endovascular treatment is established for acute large vessel occlusion stroke, FPCA occlusions were excluded from acute ischemic stroke trials. We aim to report the feasibility, safety, and outcome of mechanical thrombectomy in acute FPCA occlusions. METHODS We performed a multicenter retrospective review of consecutive patients who underwent mechanical thrombectomy of acute FPCA occlusion. Primary FPCA occlusion was defined as an occlusion that was identified on the pre‐procedure computed tomography angiography or baseline angiogram whereas a secondary FPCA occlusion was defined as an occlusion that occurred secondary to embolization to a new territory after recanalization of a different large vessel occlusion. Demographics, clinical presentation, imaging findings, endovascular treatment, and outcome were reviewed. RESULTS There were 25 patients with acute FPCA occlusion who underwent mechanical thrombectomy, distributed across 14 centers. Median National Institutes of Health Stroke Scale on presentation was 16. There were 76% (19/25) of patients who presented with primary FPCA occlusion and 24% (6/25) of patients who had a secondary FPCA occlusion. The configuration of the FPCA was full in 64% patients and partial or “fetal‐type” in 36% of patients. FPCA occlusion was missed on initial computed tomography angiography in 21% of patients with primary FPCA occlusion (4/19). The site of occlusion was posterior communicating artery in 52%, P2 segment in 40% and P3 in 8% of patients. Thrombolysis in cerebral infarction 2b/3 reperfusion was achieved in 96% of FPCA patients. There were no intraprocedural complications. At 90 days, 48% (12/25) were functionally independent as defined by modified Rankin scale≤2. CONCLUSIONS Endovascular treatment of acute FPCA occlusion is safe and technically feasible. A high index of suspicion is important to detect occlusion of the FPCA in patients presenting with anterior circulation stroke syndrome and patent anterior circulation. Novelty and significance This is the first multicenter study showing that thrombectomy of FPCA occlusion is feasible and safe.

scholarly journals Computed tomography angiography-based deep learning method for treatment selection and infarct volume prediction in anterior cerebral circulation large vessel occlusion

2021 ◽  
Vol 10 (11) ◽  
pp. 205846012110603
Author(s):  
Lasse Hokkinen ◽  
Teemu Mäkelä ◽  
Sauli Savolainen ◽  
Marko Kangasniemi
Keyword(s):  
Neural Network ◽  
Computed Tomography ◽  
Convolutional Neural Network ◽  
Computed Tomography Angiography ◽  
Time Window ◽  
Infarct Volume ◽  
Correlation Coefficients ◽  
Late Time ◽  
Large Vessel Occlusion ◽  
Vessel Occlusion

Background Computed tomography perfusion (CTP) is the mainstay to determine possible eligibility for endovascular thrombectomy (EVT), but there is still a need for alternative methods in patient triage. Purpose To study the ability of a computed tomography angiography (CTA)-based convolutional neural network (CNN) method in predicting final infarct volume in patients with large vessel occlusion successfully treated with endovascular therapy. Materials and Methods The accuracy of the CTA source image-based CNN in final infarct volume prediction was evaluated against follow-up CT or MR imaging in 89 patients with anterior circulation ischemic stroke successfully treated with EVT as defined by Thrombolysis in Cerebral Infarction category 2b or 3 using Pearson correlation coefficients and intraclass correlation coefficients. Convolutional neural network performance was also compared to a commercially available CTP-based software (RAPID, iSchemaView). Results A correlation with final infarct volumes was found for both CNN and CTP-RAPID in patients presenting 6–24 h from symptom onset or last known well, with r = 0.67 ( p < 0.001) and r = 0.82 ( p < 0.001), respectively. Correlations with final infarct volumes in the early time window (0–6 h) were r = 0.43 ( p = 0.002) for the CNN and r = 0.58 ( p < 0.001) for CTP-RAPID. Compared to CTP-RAPID predictions, CNN estimated eligibility for thrombectomy according to ischemic core size in the late time window with a sensitivity of 0.38 and specificity of 0.89. Conclusion A CTA-based CNN method had moderate correlation with final infarct volumes in the late time window in patients successfully treated with EVT.

scholarly journals Comparative Effectiveness of Endovascular Thrombectomy in Elderly Stroke Patients

Stroke ◽  
2019 ◽  
Vol 50 (4) ◽  
pp. 963-969 ◽  
Author(s):  
Ajay Malhotra ◽  
Xiao Wu ◽  
Seyedmehdi Payabvash ◽  
Charles C. Matouk ◽  
Howard P. Forman ◽  
...  
Keyword(s):  
Large Vessel ◽  
Morbidity And Mortality ◽  
Sensitivity Analyses ◽  
Tissue Type ◽  
Perfect Health ◽  
Large Vessel Occlusion ◽  
Vessel Occlusion ◽  
Endovascular Thrombectomy ◽  
The Difference ◽  
The Impact

Background and Purpose— Strokes in patients aged ≥80 years are common, and advanced age is associated with relatively poor poststroke functional outcome. The current guidelines do not recommend an upper age limit for endovascular thrombectomy (EVT). The purpose of this study is to evaluate the effectiveness of EVT in acute stroke because of large vessel occlusion for elderly patients >age 80 years. Methods— A Markov decision analytic model was constructed from a societal perspective to evaluate health outcomes in terms of quality-adjusted life years (QALYs) after EVT for acute ischemic stroke because of large vessel occlusion in patients above age 80 years. Age-specific input parameters were obtained from the most recent/comprehensive literature. Good outcome was defined as a modified Rankin Scale score ≤2. Probabilistic, 1-way, and 2-way sensitivity analyses were performed for both healthy patients and patients with disability at baseline. Results— Base case calculation showed in functionally independent patients at baseline, intravenous thrombolysis (IVT) with tPA (tissue-type plasminogen activator) only to be the better strategy with 3.76 QALYs compared to 2.93 QALYs for patients undergoing EVT. The difference in outcome is 0.83 QALY (equivalent to 303 days of life in perfect health). For patients with baseline disability, IVT only yields a utility of 1.92 QALYs and EVT yields a utility of 1.65 QALYs. The difference is 0.27 QALYs (equivalent to 99 days of life in perfect health). Multiple sensitivity analyses showed that the effectiveness of EVT is significantly determined by the morbidity and mortality after both IVT and EVT strategies, respectively. Conclusions— Our study demonstrates the impact of relevant factors on the effectiveness of EVT in patients above 80 years of age. Morbidity and mortality after both IVT and EVT strategies significantly influence the outcomes in both healthy and disabled patients at baseline. Better identification of patients not benefiting from IVT would optimize the selective use of EVT thereby improving its effectiveness.

Abstract 1122‐000154: Effect of Intravenous Thrombolysis on Early Clot Lysis in Large Vessel Occlusion Strokes Undergoing Thrombectomy

2021 ◽  
Vol 1 (S1) ◽  
Author(s):  
Mohamed Shehabeldin ◽  
Brendan Eby ◽  
Adam N Wallace ◽  
Amber Salter ◽  
Arindam R Chatterjee ◽  
...  
Keyword(s):  
Intravenous Thrombolysis ◽  
Standard Of Care ◽  
Large Vessel ◽  
Categorical Variables ◽  
Clot Lysis ◽  
Continuous Variables ◽  
Large Vessel Occlusion ◽  
Vessel Occlusion ◽  
Angiography Suite ◽  
Significant Difference

Introduction : Intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) are both standard of care treatments for acute ischemic stroke patients with large vessel occlusion (LVO) who are eligible for one or both treatments. IVT may result in early recanalization in some patients with LVO. The objective of this study is to analyze whether IVT influences pre‐thrombectomy clot lysis in LVO acute ischemic strokes. Methods : We reviewed prospectively collected data for all patients with LVO ischemic strokes who were transferred to the angiography suite with intention to perform EVT at a single comprehensive stroke center between January 2016 to December 2018. We identified subjects who showed partial or complete clot lysis vs no lysis based on the first angiographic picture of the occluded territory at the time of the initial vessel selection. Descriptive statistics were used to summarize demographic and clinical characteristics. We compared key predictor variables between lysis and no lysis groups including baseline variables, effect of IVT, time from IVT to groin puncture, LVO location, final modified treatment in cerebral ischemia (mTICI) score and discharge Modified Rankin Scale (mRS). t‐test or Kruskal‐Wallis test for continuous variables and chi square test or Fisher’s Exact test for categorical variables. Results : Two hundred and fifty‐nine patients were included. Among these patients, 10.8% (28/259) showed partial or complete lysis of the clot vs 89.2% (231/259) with no lysis. Among these patients who showed clot lysis, 16/28 (57.1%) received IVT. The use of IVT did not show differences between both groups (p = 0.18). There were no differences in the baseline characteristics except for gender, which was the only variable significantly associated with clot lysis. Men had 2‐fold higher odds of spontaneous lysis compared to females (OR [95%CI]: 2.39 [1.01, 5.65], p = 0.04). There was significant difference in the final mTICI between both groups (p <0.001). Conclusions : Our study showed that IVT in a modern practice was not associated with pre‐thrombectomy lysis. Some patients had pre‐thrombectomy lysis despite not receiving IVT.

Optimizing Outcome Prediction Scores in Patients Undergoing Endovascular Thrombectomy for Large Vessel Occlusions Using Collateral Grade on Computed Tomography Angiography

Neurosurgery ◽  
2018 ◽  
Vol 85 (3) ◽  
pp. 350-358
Author(s):  
Chang-Woo Ryu ◽  
Byung Moon Kim ◽  
Hyug-Gi Kim ◽  
Ji Hoe Heo ◽  
Hyo Suk Nam ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Computed Tomography Angiography ◽  
Outcome Prediction ◽  
Prediction Models ◽  
Large Vessel ◽  
Vascular Events ◽  
Anterior Circulation ◽  
Vessel Occlusion ◽  
Endovascular Thrombectomy ◽  
Poor Outcomes

Abstract BACKGROUND Although several outcome prediction scores incorporated with pretreatment variables have been developed for acute ischemic stroke (AIS) patients, there is not currently a prediction score that includes pretreatment imaging that can show salvageable brain tissue. OBJECTIVE To evaluate whether addition of the collateral grade on computed tomography angiography to previously published prediction scores could increase accuracy of clinical outcome prediction in endovascular thrombectomy (EVT) for AIS. METHODS This study used a retrospective multicenter registry for patients undergoing EVT for anterior circulation large vessel occlusion. Three previously published outcome prediction scores (Houston intra-arterial therapy 2, HIAT2; totaled health risks in vascular events, THRIVE; and Pittsburgh response to endovascular therapy, PRE scores) were tested in this study. Using 482 deprivation cohorts, areas under the receiver operating characteristic curves (AUC-ROCs) were compared between prediction scores with/without collateral grades in predicting the poor outcomes (modified Rankin Scale 4-6 at 3-mo follow-up) after EVT. We developed modified prediction scores by adding the collateral grade, and their advancement of outcome prediction was validated using 208 independent validation cohorts. RESULTS AUC-ROCs of HIAT2, THRIVE, and PRE scores that incorporated with collateral grade were superior in predicting poor outcomes when compared to that of the unmodified scores (P < 0.001). In modified prediction models, 3, 3, and 10 points were added for poor collateral grade to HIAT2, THRIVE, and PRE score. Modified models outperformed unmodified models in testing of the validation cohorts (P < 0.001). CONCLUSION The addition of the collateral grade to outcome prediction scores resulted in better prediction of poor outcome after EVT for AIS compared to the prediction scores alone.

scholarly journals Data augmentation for computed tomography angiography via synthetic image generation and neural domain adaptation

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Malte Seemann ◽  
Lennart Bargsten ◽  
Alexander Schlaefer
Keyword(s):  
Computed Tomography ◽  
Neural Networks ◽  
Deep Learning ◽  
Medical Imaging ◽  
Computed Tomography Angiography ◽  
Data Augmentation ◽  
Domain Adaptation ◽  
Synthetic Image ◽  
Wide Range ◽  
The Impact

AbstractDeep learning methods produce promising results when applied to a wide range of medical imaging tasks, including segmentation of artery lumen in computed tomography angiography (CTA) data. However, to perform sufficiently, neural networks have to be trained on large amounts of high quality annotated data. In the realm of medical imaging, annotations are not only quite scarce but also often not entirely reliable. To tackle both challenges, we developed a two-step approach for generating realistic synthetic CTA data for the purpose of data augmentation. In the first step moderately realistic images are generated in a purely numerical fashion. In the second step these images are improved by applying neural domain adaptation. We evaluated the impact of synthetic data on lumen segmentation via convolutional neural networks (CNNs) by comparing resulting performances. Improvements of up to 5% in terms of Dice coefficient and 20% for Hausdorff distance represent a proof of concept that the proposed augmentation procedure can be used to enhance deep learning-based segmentation for artery lumen in CTA images.

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