Modeling diffusion-weighted imaging lesion expansion between 2 and 24 h after endovascular thrombectomy in acute ischemic stroke.

PURPOSE: Diffusion-weighted imaging (DWI) lesion expansion after endovascular thrombectomy (EVT) is not well characterized. We used serial diffusion-weighted magnetic resonance imaging (MRI) to measure lesion expansion between 2 and 24 h after EVT. METHODS: In this single-center observational analysis of patients with acute ischemic stroke due to large vessel occlusion, DWI was performed post-EVT (< 2 h after closure) and 24-h later. DWI lesion expansion was evaluated using multivariate generalized linear mixed modeling with various clinical moderators. RESULTS: We included 151 patients, of which 133 (88%) had DWI lesion expansion, defined as a positive change in lesion volume between 2 and 24 h. In an unadjusted analysis, median baseline DWI lesion volume immediately post-EVT was 15.0 mL (IQR: 6.6-36.8) and median DWI lesion volume 24 h post-EVT was 20.8 mL (IQR: 9.4-66.6), representing a median change of 6.1 mL (IQR: 1.5-17.7), or a 39% increase. There were no significant associations among univariable models of lesion expansion. Adjusted models of DWI lesion expansion demonstrated that relative lesion expansion (defined as final/initial DWI lesion volume) was consistent across eTICI scores (0-2a, 0.52%; 2b, 0.49%; 2c-3, 0.42%, p = 0.69). For every 1 mL increase in lesion volume, there was 2% odds of an increase in 90-day mRS (OR: 1.021, 95%CI [1.009, 1.034], p < 0.001). CONCLUSION: We observed substantial lesion expansion post-EVT whereby relative lesion expansion was consistent across eTICI categories, and greater absolute lesion expansion was associated with worse clinical outcome. Our findings suggest that alternate endpoints for cerebroprotectant trials may be feasible.

The BAND score: A simple model for upfront prediction of poor outcomes despite successful stroke thrombectomy.

BACKGROUND: While endovascular thrombectomy (EVT) is beneficial for patients with acute large vessel occlusion ischemic strokes, a significant portion of patients still do poorly despite successful recanalization. Identifying patients at high risk for poor outcomes can be helpful for future clinical trial design and optimizing acute stroke triage. METHODS: Consecutive EVT patients were identified from 2016 to 2021 at a Comprehensive Stroke Center, and clinical information was recorded. Poor outcome was defined as a 90-day modified Rankin Scale (mRS) of 4 or greater despite achieving a modified thrombolysis in cerebral infarction (mTICI) score of 2b or greater. Multivariable regression analyses were used to identify risk factors for poor outcomes, and a scoring system was constructed. RESULTS: 483 patients with successful recanalization were identified. From a randomly selected training cohort (n = 357), the 10-point BAND score was constructed from independent risk factors for poor outcomes: baseline disability (1 point: baseline mRS ≥ 2), age (1 point: 60-69 years, 2 points: 70-79 years, 3 points: 80-84 years, 4 points: 85 years or older), NIHSS (2 points: 13-17, 3 points: 18-22, and 4 points: ≥ 23), and delay from last known normal (1 point: ≥ 6 h). The BAND score was significantly associated with rates of poor outcomes (p < 0.001), and it achieved an area under the receiver-operating characteristic curve (AUC) of 0.80 (95 %CI 0.76-0.85) in our training cohort and 0.78 (95 %CI 0.70-0.86) in our validation cohort (n = 126). Overall, the BAND score had a significantly higher AUC value than the widely validated THRIVE score and the THRIVE-EVT calculation (p = 0.001 and 0.029, respectively). Among patients with high BAND scores (7 or higher), 88.2 % had poor outcomes. CONCLUSION: The BAND score is a simple tool to predict poor outcomes despite successful recanalization. Future studies are needed to confirm the BAND score's external validity.

Intensive Blood Pressure Control After Mechanical Thrombectomy for Acute Ischemic Stroke.

Optimal blood pressure targets following successful mechanical thrombectomy remain uncertain. While some observational studies suggest that the relationship between blood pressure and outcomes follows a U-shaped curve, others suggest a linear relationship where lower is better. The recent BP-TARGET study (Blood Pressure Target in Acute Stroke to Reduce Hemorrhage After Endovascular Therapy) did not find a benefit to intensive blood pressure lowering regarding the risk of symptomatic intracranial hemorrhage, but it was not sufficiently powered to detect differences in functional outcomes. On its heels arrived the ENCHANTED2 (Enhanced Control of Hypertension and Thrombectomy Stroke Study)/mechanical thrombectomy trial, the first trial of intensive blood pressure lowering in patients with hypertension following successful mechanical thrombectomy powered to detect a difference in functional outcomes. The trial randomized patients to either a systolic blood pressure less than 120 or 140 to 180 mm Hg. The trial was terminated early due to safety concerns in the more intensive blood pressure-lowering group. In this emerging therapy critique, we explore concerns regarding the generalizability of ENCHANTED2/mechanical thrombectomy, including the high prevalence of intracranial atherosclerosis in the studied population. We survey mechanisms for poor outcomes in patients who receive overly aggressive blood pressure reduction following successful thrombectomy, such as poststroke autoregulatory compromise and persistent microcirculatory hypoperfusion. Finally, we advocate for a more moderate approach, pending further research.

Associations of Osteoarthritis With Thrombectomy Utilization and Outcomes for Large Vessel Acute Ischemic Stroke.

BACKGROUND: Osteoarthritis and other musculoskeletal disorders are the leading causes of disability in the United States. While osteoarthritis is not a direct risk factor for stroke, osteoarthritis may impact patient selection for endovascular thrombectomy (EVT) due to prestroke disability. This study investigates associations of osteoarthritis with EVT utilization and outcomes. METHODS: This was a large-scale cross-sectional study of the 2016 to 2019 National Inpatient Sample database. Adult patients with anterior large vessel ischemic strokes were identified. Patient demographics, stroke risk factors, stroke etiology, presence of osteoarthritis, medical comorbidities, EVT, intravenous thrombolysis treatments, and discharge destinations were recorded. Primary outcome was the rate of EVT treatment. Secondary outcomes include rates of discharge to home and in-hospital mortality. Propensity score matching and multivariable logistic regression models were used to account for possible confounders. RESULTS: Two hundred fifty-two thousand five hundred five patients were identified, of whom 8.5% (21 500 patients) had osteoarthritis. After propensity score matching for 32 clinical variables, osteoarthritis patients were found to be 17.3% less likely to receive EVT than non-osteoarthritis patients (14.4% versus 17.3%, respectively; P<0.001). In multivariable logistic regression analysis, osteoarthritis was associated with 22.6% lower odds of receiving EVT (OR, 0.77 [95% CI, 0.70-0.86]; P<0.001), an effect size larger than any medical comorbidity captured in this study other than dementia and nonstroke neurological disease. Among those treated with EVT, multivariable logistic regression models showed that osteoarthritis was not associated with different odds of being discharged home (OR, 0.99 [95% CI, 0.81-1.21]; P=0.93); however, osteoarthritis was marginally associated with lower odds of in-hospital mortality (OR, 0.74 [95% CI, 0.54-1.01]; P=0.054). CONCLUSIONS: Large vessel ischemic stroke patients with osteoarthritis were significantly less likely to receive EVT therapy despite similar post-EVT outcomes. These results warrant further investigation and prompt a critical review of current patient selection practices for stroke EVT therapy, specifically for patients with baseline disability due to musculoskeletal conditions such as osteoarthritis.

Prediction of blood pressure variability during thrombectomy using supervised machine learning and outcomes of patients with ischemic stroke from large vessel occlusion.

Mechanical thrombectomy (MT) is the standard of care for patients with acute ischemic stroke from large vessel occlusion (AIS-LVO). The association of blood pressure variability (BPV) during MT and outcomes are unknown. We leveraged a supervised machine learning algorithm to predict patient characteristics that are associated with BPV indices. We performed a retrospective review of our comprehensive stroke center's registry of all adult patients undergoing MT between 01/01/2016 and 12/31/2019. The primary outcome was poor functional independence, defined as 90-day modified Rankin Scale (mRS) ≥ 3. We used probit analysis and multivariate logistic regressions to evaluate the association of patients' clinical factors and outcomes. We applied a machine learning algorithm (random forest, RF) to determine predictive factors for the different BPV indices during MT. Evaluation was performed with root-mean-square error (RMSE) and normalized-RMSE (nRMSE) metrics. We analyzed 375 patients with mean age (± standard deviation [SD]) of 65 (15) years. There were 234 (62%) patients with mRS ≥ 3. Univariate probit analysis demonstrated that BPV during MT was associated with poor functional independence. Multivariable logistic regression showed that age, admission National Institutes of Health Stroke Scale (NIHSS), mechanical ventilation, and thrombolysis in cerebral infarction (TICI) score (OR 0.42, 95% CI 0.17-0.98, P = 0.044) were significantly associated with outcome. RF analysis identified that the interval from last-known-well time-to-groin puncture, age, and mechanical ventilation were among important factors significantly associated with BPV. BPV during MT was associated with functional outcome in univariate probit analysis but not in multivariable regression analysis, however, NIHSS and TICI score were. RF algorithm identified risk factors influencing patients' BPV during MT. While awaiting further studies' results, clinicians should still monitor and avoid high BPV during thrombectomy while triaging AIS-LVO candidates quickly to MT.

Volumetric White Matter Hyperintensity Ranges Correspond to Fazekas Scores on Brain MRI.

INTRODUCTION: White matter hyperintensity (WMH) is an abnormal T2 signal in the deep and subcortical white matter visualized on MRI associated with hypertension, cerebrovascular disease, and aging. The Fazekas (Fz) scoring system is a commonly used qualitative tool to assess the severity of WMH. While studies have compared Fazekas scores to other scoring methods, the comparison of Fazekas scores and volume of WMH using current semiautomated volumetric techniques has not been studied. METHODS: We reviewed MRI studies acquired at our institution between 2015 and 2017. Relative WMH was scored by one author trained in Fazekas scoring. A board certified neuroradiologist scored them independently for confirmation. Manual segmentations of WMH were completed using 3D Slicer 4.9. A 3D model was formed to quantify WMH in milliliters (mL). ANOVA tests were performed to determine the association of Fazekas scores with corresponding WMH volumes. RESULTS: Among the 198 patients in our study, WMH were visualized in 163 (Fz1: n=66; Fz2: n=49; Fz3: n=48). WMH volumes significantly differed according to Fazekas score (F = 141.1, p<0.001), with increasing WMHV associated with higher Fazekas scores: Fz1, range 0.1-8.3 mL (mean 3.7, SD 2.3); Fz2, range 6.0-17.7 mL (mean 10.8, SD 3.1); Fz3, range 14.2-77.2 mL (mean 35.2, SD 17.9); and Fz3 (excluding 11 outliers above 50 mL), 14.2-47.0 mL (mean 27.1, SD 8.9). CONCLUSION: Fazekas scores correspond with distinct ranges of WMH volume with relatively little overlap, but scores based on volumes are more efficacious. A modified Fazekas from 0-4 should be considered.

Survey of radiologists and emergency department providers after implementation of a global radiology report categorization system.

PURPOSE: Breakdown in communication of important imaging results threatens patient safety and risks malpractice claims. To facilitate closed-loop communication, our institution developed a unique radiology report categorization (RADCAT) system employing automated alert notification systems. This study aimed to understand users' initial experiences with the RADCAT system and obtain feedback. METHODS: Web-based surveys were distributed to radiologists and emergency department (ED) providers at our hospital system within 1 year of institution-wide RADCAT implementation. Survey designs differed based on clinical setting. Most prompts utilized declarative statements with 5-point agreement Likert scales. Closed-response data was analyzed with descriptive statistics. RESULTS: Response rates among radiologists and ED providers were 59.4% (63/106) and 38.4% (69/211), respectively. 78.0% (46/59) of radiologists and 60.9% (42/69) of ED providers agreed that RADCAT improves patient care. Of radiologists, 84.1% (53/63) agreed that RADCAT design is intuitive, and 57.6% (34/59) agreed that RADCAT improves efficiency. Of ED providers, 69.6% (48/69) agreed that RADCAT appropriately differentiates urgent and non-urgent findings, and 65.2% (45/69) agreed that auto-population of discharge documents with imaging results containing follow-up recommendations protects them from liability. Only 35.6% (21/59) of radiologists and 21.7% (15/69) of ED providers agreed that RADCAT implementation decreased reading room visits by ordering providers. Open-response feedback showed that some ED providers find RADCAT too complex while some radiologists desire improved transparency regarding imaging study communication status. CONCLUSION: Since its implementation, RADCAT has been well received among radiologists and ED providers with agreement that it improves patient care and effectively distinguishes and communicates important imaging findings.

Effects of multiphase versus single-phase CT angiography for the detection of distal cerebral vessel occlusion.

PURPOSE: The goal of this study was to determine whether the benefits of multiphase CTA (mCTA) over single-phase CTA (sCTA) for the detection of proximal cerebrovascular occlusions similarly extend to the distal cerebral vasculature. METHODS: Four attending radiologists, two neuroradiologists and two emergency radiologists, contributed as readers to this retrospective study. For each reader, two sessions were conducted, one using sCTA and one using mCTA. During each session, the reader interpreted the studies of 104 patients who underwent imaging for suspicion of acute ischemic stroke, resulting in a total of 832 interpretations. Changes in diagnostic accuracy, time to render final decision, and reported levels of reader confidence were quantitatively assessed. Further analysis comparing the effects for neuroradiologists versus emergency radiologists was additionally conducted. RESULTS: Using mCTA resulted in a significant 5.0% absolute increase in sensitivity (91.6% vs. 96.6%, p = .004) and an insignificant increase in specificity (99.5% vs. 99.7%, p = .39). A significant reduction in reading time (66.7 s vs. 59.6 s, p = .001) and an increase in diagnostic confidence (2.26 vs. 2.58, p < .001) were observed. Using sCTA, higher sensitivity was achieved by neuroradiologists than emergency radiologists (96.0% vs. 86.9%, p = .002); using mCTA resulted in an absolute increase in sensitivity of 0.9% (97.4%, p = .44) for neuroradiologists and 9.6% (96.5%, p < .001) for emergency radiologists, eliminating significant differences between the groups (p = 0.57). CONCLUSION: The use of mCTA results in increased sensitivity and negative predictive value, decreased reading time, increased diagnostic confidence, and the elimination of differences in accuracy between neuroradiologists and emergency radiologists.

Detection of emergent large vessel occlusion stroke with CT angiography is high across all levels of radiology training and grayscale viewing methods.

OBJECTIVES: CT angiography (CTA) is essential in acute stroke to detect emergent large vessel occlusions (ELVO) and must be interpreted by radiologists with and without subspecialized training. Additionally, grayscale inversion has been suggested to improve diagnostic accuracy in other radiology applications. This study examines diagnostic performance in ELVO detection between neuroradiologists, non-neuroradiologists, and radiology residents using standard and grayscale inversion viewing methods. METHODS: A random, counterbalanced experimental design was used, where 18 radiologists with varying experiences interpreted the same patient images with and without grayscale inversion. Confirmed positive and negative ELVO cases were randomly ordered using a balanced design. Sensitivity, specificity, positive and negative predictive values as well as confidence, subjective assessment of image quality, time to ELVO detection, and overall interpretation time were examined between grayscale inversion (on/off) by experience level using generalized mixed modeling assuming a binary, negative binomial, and binomial distributions, respectively. RESULTS: All groups of radiologists had high sensitivity and specificity for ELVO detection (all > .94). Neuroradiologists were faster than non-neuroradiologists and residents in interpretation time, with a mean of 47 s to detect ELVO, as compared with 59 and 74 s, respectively. Residents were subjectively less confident than attending physicians. With respect to grayscale inversion, no differences were observed between groups with grayscale inversion vs. standard viewing for diagnostic performance (p = 0.30), detection time (p = .45), overall interpretation time (p = .97), and confidence (p = .20). CONCLUSIONS: Diagnostic performance in ELVO detection with CTA was high across all levels of radiologist training level. Grayscale inversion offered no significant detection advantage. KEY POINTS: • Stroke is an acute vascular syndrome that requires acute vascular imaging. • Proximal large vessel occlusions can be identified quickly and accurately by radiologists across all training levels. • Grayscale inversion demonstrated minimal detectable benefit in the detection of proximal large vessel occlusions.

Comparison of Outcomes After Treatment of Large Vessel Occlusion in a Critical Care Resuscitation Unit or a Neurocritical Care Unit.

BACKGROUND: Mechanical thrombectomy (MT) has become first-line treatment for patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO). Delay in the interhospital transfer (IHT) of patients from referral hospitals to a comprehensive stroke center is associated with worse outcomes. At our academic tertiary care facility in an urban setting, a neurocritical care and emergency neurology unit (NCCU) receives patients with AIS-LVO from outlying medical facilities. When the NCCU is full, patients with AIS-LVO are initially transferred to a critical care resuscitation unit (CCRU). We were interested in quantifying the numbers of AIS-LVO patients treated in those two units and assessing their outcomes. We hypothesized that the CCRU would facilitate an increase in IHTs and provide care comparable to that delivered by the subspecialty NCCU. METHODS: We conducted a retrospective study of the medical center's prospective stroke registry for adult IHT patients undergoing MT between 01/01/2015 and 12/31/2017. Primary outcome was time from consultation and request for transfer to arrival (Consult-Arrival). Other outcomes of interest were functional independence, defined as 90-day modified Rankin Scale (mRS) score ≤ 2, and 90-day all-cause mortality. Multivariable logistic regression was performed to assess association between clinical factors, mortality, and functional independence. RESULTS: We analyzed the records of 128 IHT patients: 87 (68%) were admitted to the CCRU, and 41 (32%) to the NCCU. The two groups had similar baseline characteristics (age, National Institutes of Health Stroke Scale score, Alberta Stroke Program Early Computed Tomography scores [ASPECTS]). The median Consult-Arrival time was shorter for CCRU patients than for the NCCU patients (86 [88‒109] vs 100 [77‒127] [p = 0.031]). The 90-day mortality rates (16 vs 30% [p = 0.052]) and the rates having a mRS score ≤ 2 (31 vs 36% [p = 0.59]) were not statistically different. Multivariable logistic regression showed that each minute of delay in the Consult-Arrival time was associated with 2.3% increase in the likelihood of death (OR 1.023; 95% CI 1.003‒1.04 [p = 0.026]), while high thrombolysis in cerebral infarction score was the only factor that was significantly associated with functional independence at 90 days (OR 2.9; 95% CI 1.4‒6.4 [p = 0.006]). CONCLUSION: The CCRU increased AIS-LVO patients' access to definitive care and reduced their transfer time from outlying medical facilities while achieving outcomes similar to those attained by patients treated in the subspecialty NCCU. We conclude that a resuscitation unit can complement the NCCU to care for patients in the hyperacute phase of AIS-LVO.

Transport Blood Pressures and Outcomes in Stroke Patients Requiring Thrombectomy.

OBJECTIVE: Mechanical thrombectomy is the treatment of choice for acute ischemic strokes from large vessel occlusions. Absolute blood pressure and blood pressure variability (BPV) may affect patients' outcome. We hypothesized that patients' outcomes were not associated with BPV during transport between hospitals in the era of effective thrombectomy. METHODS: We performed a retrospective observational review of adult patients admitted to our comprehensive stroke center who underwent mechanical thrombectomy between January 1, 2015, and December 31, 2018. Data were collected from our stroke registry and transportation records. Outcomes were defined as 90-day modified Rankin Scale (mRS) ≤2 and any acute kidney injury (AKI) during hospitalization. RESULTS: We analyzed 134 eligible patients. The mean age was 66 years (standard deviation = 14 years). Forty percent achieved mRS ≤2, and 16% had an AKI. BPV and maximum systolic blood pressures during transport were examined as variables to determine outcome. We found BPV was similar between patients with good and bad functional independence. Furthermore, the maximum systolic blood pressure during transport (odds ratio = 0.98; 95% confidence interval, 0.96-0.99; P = .038), not BPV, was associated with a lower likelihood of mRS ≤2. No similar correlation of analyzed blood pressure variables could be found for AKI as an outcome. CONCLUSION: The maximum systolic blood pressure was associated with worse functional outcomes in stroke patients transported for thrombectomy. Prehospital clinicians should be cognizant of high blood pressure among patients with acute ischemic stroke from large vessel occlusion during transport and treat accordingly.

Impact of Balloon Guide Catheter Use on Clinical and Angiographic Outcomes in the STRATIS Stroke Thrombectomy Registry.

Background and Purpose- Mechanical thrombectomy has been shown to improve clinical outcomes in patients with acute ischemic stroke. However, the impact of balloon guide catheter (BGC) use is not well established. Methods- STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter study of patients with large vessel occlusion treated with the Solitaire stent retriever as first-line therapy. In this study, an independent core laboratory, blinded to the clinical outcomes, reviewed all procedures and angiographic data to classify procedural technique, target clot location, recanalization after each pass, and determine the number of stent retriever passes. The primary clinical end point was functional independence (modified Rankin Scale, 0-2) at 3 months as determined on-site, and the angiographic end point was first-pass effect (FPE) success rate from a single device attempt (modified Thrombolysis in Cerebral Infarction, ≥2c) as determined by a core laboratory. Achieving modified FPE (modified Thrombolysis in Cerebral Infarction, ≥2b) was also assessed. Comparisons of clinical outcomes were made between groups and adjusted for baseline and procedural characteristics. All participating centers received institutional review board approval from their respective institutions. Results- Adjunctive technique groups included BGC (n=445), distal access catheter (n=238), and conventional guide catheter (n=62). The BGC group had a higher rate of FPE following first pass (212/443 [48%]) versus conventional guide catheter (16/62 [26%]; P=0.001) and distal access catheter (83/235 [35%]; P=0.002). Similarly, the BGC group had a higher rate of modified FPE (294/443 [66%]) versus conventional guide catheter (26/62 [42%]; P<0.001) and distal access catheter (129/234 [55%]; P=0.003). The BGC group achieved the highest rate of functional independence (253/415 [61%]) versus conventional guide catheter (23/55 [42%]; P=0.007) and distal access catheter (113/218 [52%]; P=0.027). Final revascularization and mortality rates did not differ across the groups. Conclusions- BGC use was an independent predictor of FPE, modified FPE, and functional independence, suggesting that its routine use may improve the rates of early revascularization success and good clinical outcomes. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.

Information availability on emergency radiology fellowship websites: current state and paths to improvement.

PURPOSE: The purpose of this study is to detail the current state of the websites of each of the currently established emergency radiology fellowship programs within the USA, in terms of publicly available information. The goal of the project is to present data for emergency radiology fellowship programs to tailor that information to attract those most interested in the pursuit of an emergency radiology fellowship position. METHODS: Emergency radiology fellowship programs were identified using the American Society of Emergency Radiology website and recent published literature. The website for each program was evaluated for the presence or absence of 23 discrete areas of information. Additionally, information from a prior study evaluating radiology resident's opinions on desired information for interventional radiology fellowship websites was utilized and compared to the information currently available on emergency radiology fellowship websites. RESULTS: Eighteen emergency radiology fellowship programs were initially identified. One program website was inaccessible at the time of data collection. Of the remaining 17 program websites, contact information, application requirements, program description, stand-alone website, length of fellowship, research opportunities, salary, and other benefits were available for greater than 75% of programs, while listing of current fellows, moonlighting opportunities, social information, and alumni information were available at fewer than 25% of program websites. CONCLUSION: There is broad variability in the type and amount of data available to potential emergency radiology fellows across the surveyed program websites. Several key areas-specifically, listings of current fellows, rotation schedules, facility descriptions, and didactic information-present high-yield opportunities for improvement of desired accessible data.

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke).

BACKGROUND: Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation. METHODS: STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0-2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass. RESULTS: A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients (P<0.001). Clinical outcomes were better in the direct group, with 60.0% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06-1.79; P=0.02). Likewise, excellent outcome (modified Rankin Score 0-1) was achieved in 47.4% (236/498) of direct patients versus 38.0% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13-1.92; P=0.005). Mortality did not differ between the 2 groups (15.1% for direct, 13.7% for transfer; P=0.55). Intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but MT would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and MT performed 94 minutes earlier. CONCLUSIONS: In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke: Primary Results of the STRATIS Registry.

BACKGROUND AND PURPOSE: Mechanical thrombectomy with stent retrievers has become standard of care for treatment of acute ischemic stroke patients because of large vessel occlusion. The STRATIS registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) aimed to assess whether similar process timelines, technical, and functional outcomes could be achieved in a large real world cohort as in the randomized trials. METHODS: STRATIS was designed to prospectively enroll patients treated in the United States with a Solitaire Revascularization Device and Mindframe Capture Low Profile Revascularization Device within 8 hours from symptom onset. The STRATIS cohort was compared with the interventional cohort of a previously published SEER patient-level meta-analysis. RESULTS: A total of 984 patients treated at 55 sites were analyzed. The mean National Institutes of Health Stroke Scale score was 17.3. Intravenous tissue-type plasminogen activator was administered in 64.0%. The median time from onset to arrival in the enrolling hospital, door to puncture, and puncture to reperfusion were 138, 72, and 36 minutes, respectively. The Core lab-adjudicated modified Thrombolysis in Cerebral Infarction ≥2b was achieved in 87.9% of patients. At 90 days, 56.5% achieved a modified Rankin Scale score of 0 to 2, all-cause mortality was 14.4%, and 1.4% suffered a symptomatic intracranial hemorrhage. The median time from emergency medical services scene arrival to puncture was 152 minutes, and each hour delay in this interval was associated with a 5.5% absolute decline in the likelihood of achieving modified Rankin Scale score 0 to 2. CONCLUSIONS: This largest-to-date Solitaire registry documents that the results of the randomized trials can be reproduced in the community. The decrease of clinical benefit over time warrants optimization of the system of care. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Assessment of a modified technique for air delivery during fluoroscopic-monitored pneumatic intussusception reduction.

BACKGROUND: Intussusception is one of the most common causes of acute abdominal emergency in children. Image-monitored pressure reduction is the first line of treatment. OBJECTIVE: We report on a modified technique of air delivery during fluoroscopic-monitored pneumatic intussusception reductions, and compare it with an established technique. MATERIALS AND METHODS: We modified the Shiels intussusception reduction device so that the air used for intussusception reduction is delivered not by the device's insufflator bulb, but rather by the hospital medical air supply system, eliminating the need for continuous pumping of the insufflator bulb during the procedure. Subsequently, we retrospectively compared sequential fluoroscopy-monitored pneumatic intussusception reduction procedures performed in patients younger than 18 years using either the standard or modified devices, evaluating technical procedure parameters (i.e. median procedure time length, fluoroscopy time length and radiation dose) and patient outcomes (i.e. number of complete intussusception reductions, number of incomplete intussusception reductions, number of intussusception recurrences within 3 days of the procedure, number of procedures followed by surgery). RESULTS: We found no statistically significant differences between procedures performed with the standard and modified techniques. CONCLUSION: The device modification allows for increased operator comfort. Evaluated procedure parameters and patient outcomes appear similar to those of the standard technique.

Incidence of contrast material-induced nephropathy after neuroendovascular procedures.

PURPOSE: To report the incidence and risk factors for contrast material ( CM contrast material )-induced nephropathy ( CIN CM-induced nephropathy ) in patients with no history of chronic kidney disease and estimated glomerular filtration rate that exceeded 30 mL/min/1.73 m(2) after a relatively high dose of CM contrast material (≥250 mL) during neuroendovascular procedures. MATERIALS AND METHODS: An institutional review board-approved retrospective chart review was performed for all patients who received a dose of CM contrast material 250 mL or greater while they underwent a neuroendovascular procedure between January 2011 and February 2013. The control group consisted of comparable patients who received a CM contrast material dose of 75-249 mL during the same period. Patients with pre-existing estimated glomerular filtration rate of 30 mL/min/1.73 m(2) or less or documented history of chronic kidney disease were excluded. CIN CM-induced nephropathy was defined as an increase in serum creatinine 50% above the baseline or an absolute increase of 0.3 mg/dL at either 24 or 48 hours after the procedure. Statistical analysis was performed with the Student t test, χ(2) analysis, and mixed-model analysis of variance. RESULTS: Clinical characteristics between the control and high-dose group were similar for age (95% confidence interval [CI]: -3.69, 5.48; P = .70), sex (95% CI: 0.28, 0.43; P = .62), and ethnicity (95% CI: 0.42, 0.58; P = .47). The average volume of CM contrast material administered was 172 mL in the control group and 326 mL in the high-dose cohort (95% CI: 131.78, 175.05; P < .001). Of the 79 cases in the high-dose cohort, 36 (46%) received a CM contrast material dose between 250 and 299 mL, 29 (37%) received 300-399 mL, nine (11%) received 400-499 mL, and five (6%) received greater than 500 mL. By 48 hours, a statistically significant decrease in serum creatinine was seen in two of the four high-dose CM contrast material dose categories: 250-299 mL (decrease of 24%; [95% CI: 0.04, 0.36]; P = .003) and greater than 500 mL (decrease of 14% [95% CI: -0.33, 0.57]; P = .007). There were four cases (5%) of CIN CM-induced nephropathy : three (4%) at 24 hours and one (1%) at 48 hours. The comorbid rate of diabetes (25% vs 15% [95% CI: -0.01, 0.04]; P < .001) was found to be higher among those who developed CIN CM-induced nephropathy compared with those who did not within the high-dose cohort. No cases of CIN CM-induced nephropathy occurred in the control group. CONCLUSION: Risk of developing CIN CM-induced nephropathy is relatively low in patients who undergo neuroendovascular procedures with CM contrast material doses of 250 mL or greater.

Relationship of thrombus length to number of stent retrievals, revascularization, and outcomes in acute ischemic stroke.

PURPOSE: To study the relationship between intracranial thrombus length and number of stent retrievals, revascularization rates, and functional outcomes in stroke. MATERIALS AND METHODS: Retrospective data were collected from consecutive cases of stroke treated with endovascular procedures at a single institution from April 2012-September 2013. Thrombus length was measured in the anterior cerebral circulation. Demographic and clinical details; involved vessels; and procedural details, including the number of devices used and number of retrievals used for each device, were recorded. Revascularization rates and 90-day functional outcomes were recorded. RESULTS: Data regarding the length of thrombus in the anterior cerebral circulation were available for 28 patients. There was no significant association between thrombus length and number of stent retrievals (P = .3780), final thrombolysis in cerebral infarction (TICI) score (P = .4835), or 90-day modified Rankin Scale score (P = .4146). There was a significant difference (P = .0280) between number of retrievals and final TICI score, with lower number of retrieval passes corresponding to higher final TICI scores. CONCLUSIONS: The data suggest no relationship between thrombus length and number of stent retrievals, final TICI score, or functional neurologic outcomes at 90 days in stent retrieval thrombectomy for acute ischemic stroke. These results do not support a predictive value for thrombus length quantification in the evaluation of stroke.

Distraction osteogenesis for complex foot deformities: Gigli saw midfoot osteotomy with external fixation.

Open midfoot wedge osteotomy correction can cause neurovascular compromise, requires extensive exposure, sacrifices normal joints, and shortens the foot. We used a minimally invasive technique to treat complex foot deformities by combining percutaneous Gigli saw midfoot osteotomy, circular external fixation, and acute, gradual, or gradual with acute manipulation correction. The medical records of 23 patients (26 feet) with complex foot deformities (congenital, 18 feet; neuromuscular, 4 feet; post-traumatic, 3 feet; malunion, 1 foot) who had undergone treatment within an 18-year period (1990 through 2007) were retrospectively reviewed. We also performed the procedure on 10 cadaveric limbs to determine whether anatomic structures were at risk. Correction was achieved in all feet. The mean duration of external fixation treatment was 4.2 (range 3 to 7) months. The mean follow-up duration was 4.7 (range 2 to 18) years. A significant difference was observed in the pre- and postoperative, lateral view, talar-first metatarsal angle (p = .001). Minor complications (4 feet) consisted of bony exostoses. Major complications included recurrent deformity in 3 feet and sural nerve entrapment in 1 foot. Two patients had mild and one moderate foot pain. Three patients had impaired gait function; the remaining patients had functional gait. The mean interval until wearing regular shoes after external fixation removal was 2.3 (range 1 to 4) months. All but 1 of the patients were satisfied with the final results. We observed no cadaveric neurovascular injury. Our results have shown that percutaneous Gigli saw midfoot osteotomy can be performed without neurovascular injury and is capable of successfully correcting complex foot deformities.

Optimal Angiographic Goal and Number of Passes for Octogenarians Undergoing Endovascular Stroke Thrombectomy.

BACKGROUND: The optimal recanalization goal and number of endovascular thrombectomy (EVT) passes for elderly patients with large vessel occlusion strokes is unclear. METHODS: Consecutive patients 80 years or older undergoing EVT were identified from 2016 to 2022 at a single center. Clinical information, procedural details, and modified treatment in cerebral ischemia (mTICI) scores were collected. Primary outcome was modified Rankin scale (mRS) at 90 days. Bivariate and multivariable analyses were conducted to assess associations between mTICI scores, EVT passes, and 90-day outcomes. RESULTS: One hundred twenty-six patients were identified. At 90 days, mTICI 2b recanalization resulted in high rates of poor outcomes (8.7% functional independence and 60.9% mortality) not significantly different from mTICI 0, 1 or 2a (median mRS 6 vs. 6, P = 0.61). Complete recanalization (mTICI 2c or 3) led to significantly better mRS outcomes at 90 days compared to mTICI 2b (median mRS 4 vs. 6, adjusted P = 0.038), with 26.8% functional independence and 37.8% mortality. In multivariable analysis, complete recanalization was significantly associated with better 90-day outcomes than mTICI 2b or lower recanalization (odds ratio 4.24 [95% Confidence interval 1.46-12.3]; P = 0.002), while the number of passes was not independently associated with worse outcomes (P = 0.98). CONCLUSIONS: For octogenarians, mTICI 2b recanalization yields limited clinical benefit and results in poor 90-day outcomes. In contrast, complete recanalization is independently associated with significantly better outcomes. Thus, once the decision is made to pursue EVT in the elderly, mTICI 2c or better recanalization should be the angiographic goal. Providers should not withhold thrombectomy passes based on age alone.