Machine Learning in Acute Ischemic Stroke Neuroimaging

Machine Learning (ML) through pattern recognition algorithms is currently becoming an essential aid for the diagnosis, treatment, and prediction of complications and patient outcomes in a number of neurological diseases. The evaluation and treatment of Acute Ischemic Stroke (AIS) have experienced a significant advancement over the past few years, increasingly requiring the use of neuroimaging for decision-making. In this review, we offer an insight into the recent developments and applications of ML in neuroimaging focusing on acute ischemic stroke

Aspiration thrombectomy of M2 middle cerebral artery occlusion to treat acute ischemic stroke: A core lab–adjudicated subset analysis from the COMPLETE registry and literature review

Background Although the benefits of aspiration thrombectomy for treating acute ischemic stroke caused by proximal large vessel occlusion have been established, fewer data are available for evaluating aspiration thrombectomy of distal occlusion. The objective of this study was to evaluate, by means of prospectively collected data, the safety and efficacy of aspiration thrombectomy in patients with M2 middle cerebral artery (MCA) occlusion. Methods This study is a subset analysis of a global prospective multicenter observational registry that included patients who presented with either anterior or posterior large vessel occlusion and were eligible for mechanical thrombectomy using the Penumbra System including the Penumbra 3D Revascularization Device. For this analysis, all patients in the registry with M2 MCA occlusion were included. Results Of the 650 patients in the registry, 113 (17.4%) had M2 MCA occlusion. The rate of a modified treatment in cerebral infarction score of 2b to 3 after the procedure was 79.6% (90/113), the rate of a modified Rankin Scale score of 0–2 at 90 days was 72.5% (79/109), and the all-cause mortality rate at 90 days was 8.8% (10/113). Device-related serious adverse events occurred in one patient (0.9%) within 24 h and in two patients (1.8%) overall. Procedure-related serious adverse events occurred in four patients (3.5%) within 24 h and in six patients (5.3%) overall (nine events). Conclusion For appropriately selected patients, aspiration thrombectomy for acute ischemic stroke due to M2 MCA occlusion was safe and effective, with high rates of technical success and good functional outcome

Underutilization of Endovascular Therapy in Black Patients With Ischemic Stroke: An Analysis of State and Nationwide Cohorts

BACKGROUND AND PURPOSE: Endovascular therapy (EVT) is a very effective treatment but relies on specialized capabilities that are not available in every hospital where acute ischemic stroke is treated. Here, we assess whether access to and utilization of this therapy has extended uniformly across racial and ethnic groups. METHODS: We conducted a retrospective, population-based study using the 2019 Texas Inpatient Public Use Data File. Acute ischemic stroke cases and EVT use were identified using the RESULTS: Among 40 814 acute ischemic stroke cases in Texas in 2019, 54% were White, 17% Black, and 21% Hispanic. Black patients had similar admissions to EVT-performing hospitals and greater admissions to comprehensive stroke centers (CSCs) compared with White patients (EVT 62% versus 62%, CONCLUSIONS: We found no evidence of disparity in presentation to EVT-performing hospitals or CSCs; however, lower rates of EVT were observed in Black patients

An open-access endoscopy screen correctly and safely identifies patients for conscious sedation

Background and aims: Open-access scheduling is highly utilized for facilitating generally low-risk endoscopies. Preprocedural screening addresses sedation requirements; however, procedural safety may be compromised if screening is inaccurate. We sought to determine the reliability of our open-access scheduling system for appropriate use of conscious sedation. Methods: We prospectively and consecutively enrolled outpatient procedures booked at an academic center by open-access using screening after in-office gastroenterology (GI) consultation. We collected the cases inappropriately booked for conscious sedation and compared the characteristics for significant differences. Results: A total of 8063 outpatients were scheduled for procedures with conscious sedation, and 5959 were booked with open-access. Only 78 patients (0.97%, 78/8063) were identified as subsequently needing anesthesiologist-assisted sedation; 44 (56.4%, 44/78) were booked through open-access, of which chronic opioid (47.7%, 21/44) or benzodiazepine use (34.1%, 15/44) were the most common reasons for needing anesthesiologist-assisted sedation. Patients on chronic benzodiazepines required more midazolam than those not on chronic benzodiazepines (P = .03) of those patients who underwent conscious sedation. Similarly, patients with chronic opioid use required more fentanyl than those without chronic opioid use (P = .04). Advanced liver disease and alcohol use were common reasons for patients being booked after in-office consultation and were significantly higher than those booked with open-access (both P < .01). Conclusions: We observed that the majority of patients can be triaged for conscious sedation using a multi-tiered screening process. Importantly, few patients (<1.0%) were inappropriately booked for conscious sedation. The most common reasons for considering anesthesiologist-assisted sedation were chronic opioid, benzodiazepine and/or alcohol use and advanced liver disease. This suggests that these entities could be included in screening processes for open-access scheduling

The Society of Vascular and Interventional Neurology (SVIN) Mechanical Thrombectomy Registry: Methods and Primary Results

Background A better understanding of real‐world practice patterns in the endovascular treatment for large vessel occlusion acute ischemic stroke is needed. Here, we report the methods and initial results of the Society of Vascular and Interventional Neurology (SVIN) Registry. Methods The SVIN Registry is an ongoing prospective, multicenter, observational registry capturing patients with large vessel occlusion acute ischemic stroke undergoing endovascular treatment since November 2018. Participating sites also contributed pre‐SVIN Registry data collected per institutional prospective registries, and these data were combined with the SVIN Registry in the SVIN Registry+ cohort. Results There were 2088 patients treated across 11 US centers included in the prospective SVIN Registry and 5372 in SVIN Registry+. In the SVIN Registry cohort, the median number of enrollments per institution was 160 [interquartile range 53–243]. Median age was 67 [58–79] years, 49% were women, median National Institutes of Health Stroke Scale 16 [10–21], Alberta stroke program early CT score 9 [7–10], and 20% had baseline modified Rankin scale (mRS)≥2. The median last‐known normal to puncture time was 7.7 [3.1–11.5] hours, and puncture‐to‐reperfusion was 33 [23–52] minutes. The predominant occlusion site was the middle cerebral artery‐M1 (45%); medium vessel occlusions occurred in 97(4.6%) patients. The median number of passes was 1 [1–3] with 93% achieving expanded Treatment In Cerebral Ischemia2b50–3 reperfusion and 51% expanded Treatment In Cerebral Ischemia3/complete reperfusion. Symptomatic intracranial hemorrhage occurred in 5.3% of patients, with 37.3% functional independence (mRS0–2) and 26.4% mortality rates at 90‐days. Multivariable regression indicated older age, longer last‐normal to reperfusion, higher baseline National Institutes of Health Stroke Scale and glucose, lower Alberta stroke program early CT score, heart failure, and general anesthesia associated with lower 90‐day chances of mRS0–2 at 90‐days. Demographic, imaging, procedural, and clinical outcomes were similar in the SVIN Registry+. A comparison between AHA Guidelines‐eligible patients from the SVIN Registry against the Highly Effective Reperfusion evaluated in Multiple Endovascular Stroke Trials study population demonstrated comparable clinical outcomes. Conclusions The prospective SVIN Registry demonstrates that satisfactory procedural and clinical outcomes can be achieved in real‐world practice, serving as a platform for local quality improvement and the investigation of unexplored frontiers in the endovascular treatment of acute stroke

Middle Meningeal artery Embolization For Chronic Subdural Hematomas With Concurrent antithrombotics

BACKGROUND: Chronic subdural hematoma (CSDH) is an increasingly prevalent disease in the aging population. Patients with CSDH frequently suffer from concurrent vascular disease or develop secondary thrombotic complications requiring antithrombotic treatment. OBJECTIVE: to determine the safety and impact of early reinitiation of antithrombotics after middle meningeal artery embolization for chronic subdural hematoma. METHODS: This is a single-institution, retrospective study of patients who underwent middle meningeal artery (MMA) embolizations for CSDH. Patient with or without antithrombotic initiation within 5 days postembolization were compared. Primary outcome was the rate of recurrence within 60 days. Secondary outcomes included rate of reoperation, reduction in CSDH thickness, and midline shift. RESULTS: Fifty-seven patients met inclusion criteria. The median age was 66 years (IQR 58-76) with 21.1% females. Sixty-six embolizations were performed. The median length to follow-up was 20 days (IQR 14-44). Nineteen patients (33.3%) had rapid reinitiation of antithrombotics (5 antiplatelet, 11 anticoagulation, and 3 both). Baseline characteristics between the no antithrombotic (no-AT) and the AT groups were similar. The recurrence rate was higher in the AT group (no-AT vs AT, 9.3 vs 30.4%, P = .03). Mean absolute reduction in CSDH thickness and midline shift was similar between groups. Rate of reoperation did not differ (4.7 vs 8.7%, P = .61). CONCLUSION: Rapid reinitiation of AT after MMA embolization for CSDH leads to higher rates of recurrence with similar rates of reoperation. Care must be taken when initiating antithrombotics after treatment of CSDH with MMA embolization

Middle Meningeal artery Embolization of Septated Chronic Subdural Hematomas

INTRODUCTION: Middle meningeal artery embolization (MMAE) has emerged as a promising new treatment for patients with chronic subdural hematomas (cSDH). Its efficacy, however, upon the subtype with a high rate of recurrence-septated cSDH-remains undetermined. METHODS: From our prospective registry of patients with cSDH treated with MMAE, we classified patients based on the presence or absence of septations. The primary outcome was the rate of recurrence of cSDH. Secondary outcomes included a reduction in cSDH thickness, midline shift, and rate of reoperation. RESULTS: Among 80 patients with 99 cSDHs, the median age was 68 years (IQR 59-77) with 20% females. Twenty-eight cSDHs (35%) had septations identified on imaging. Surgical evacuation with burr holes was performed in 45% and craniotomy in 18.8%. Baseline characteristics between no-septations (no-SEP) and septations (SEP) groups were similar except for median age (SEP vs no-SEP, 72.5 vs. 65.5, p CONCLUSION: MMAE appears to be equal to potentially more effective in preventing the recurrence of cSDH in septated lesions. These findings may aid in patient selection

Machine Learning Automated Detection of Large Vessel Occlusion From Mobile Stroke Unit Computed Tomography Angiography

BACKGROUND: Prehospital automated large vessel occlusion (LVO) detection in Mobile Stroke Units (MSUs) could accelerate identification and treatment of patients with LVO acute ischemic stroke. Here, we evaluate the performance of a machine learning (ML) model on CT angiograms (CTAs) obtained from 2 MSUs to detect LVO. METHODS: Patients evaluated on MSUs in Houston and Los Angeles with out-of-hospital CTAs were identified. Anterior circulation LVO was defined as an occlusion of the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery vessels and determined by an expert human reader. A ML model to detect LVO was trained and tested on independent data sets consisting of in-hospital CTAs and then tested on MSU CTA images. Model performance was determined using area under the receiver-operator curve statistics. RESULTS: Among 68 patients with out-of-hospital MSU CTAs, 40% had an LVO. The most common occlusion location was the middle cerebral artery M1 segment (59%), followed by the internal carotid artery (30%), and middle cerebral artery M2 (11%). Median time from last known well to CTA imaging was 88.0 (interquartile range, 59.5-196.0) minutes. After training on 870 in-hospital CTAs, the ML model performed well in identifying LVO in a separate in-hospital data set of 441 images with area under receiver-operator curve of 0.84 (95% CI, 0.80-0.87). ML algorithm analysis time was under 1 minute. The performance of the ML model on the MSU CTA images was comparable with area under receiver-operator curve 0.80 (95% CI, 0.71-0.89). There was no significant difference in performance between the Houston and Los Angeles MSU CTA cohorts. CONCLUSIONS: In this study of patients evaluated on MSUs in 2 cities, a ML algorithm was able to accurately and rapidly detect LVO using prehospital CTA acquisitions

Automated Large Vessel Occlusion Detection Software and Thrombectomy Treatment Times: a Cluster Randomized Clinical Trial

IMPORTANCE: The benefit of endovascular stroke therapy (EVT) in large vessel occlusion (LVO) ischemic stroke is highly time dependent. Process improvements to accelerate in-hospital workflows are critical. OBJECTIVE: to determine whether automated computed tomography (CT) angiogram interpretation coupled with secure group messaging can improve in-hospital EVT workflows. DESIGN, SETTING, AND PARTICIPANTS: This cluster randomized stepped-wedge clinical trial took place from January 1, 2021, through February 27, 2022, at 4 comprehensive stroke centers (CSCs) in the greater Houston, Texas, area. All 443 participants with LVO stroke who presented through the emergency department were treated with EVT at the 4 CSCs. Exclusion criteria included patients presenting as transfers from an outside hospital (n = 158), in-hospital stroke (n = 39), and patients treated with EVT through randomization in a large core clinical trial (n = 3). INTERVENTION: Artificial intelligence (AI)-enabled automated LVO detection from CT angiogram coupled with secure messaging was activated at the 4 CSCs in a random-stepped fashion. Once activated, clinicians and radiologists received real-time alerts to their mobile phones notifying them of possible LVO within minutes of CT imaging completion. MAIN OUTCOMES AND MEASURES: Primary outcome was the effect of AI-enabled LVO detection on door-to-groin (DTG) time and was measured using a mixed-effects linear regression model, which included a random effect for cluster (CSC) and a fixed effect for exposure status (pre-AI vs post-AI). Secondary outcomes included time from hospital arrival to intravenous tissue plasminogen activator (IV tPA) bolus in eligible patients, time from initiation of CT scan to start of EVT, and hospital length of stay. In exploratory analysis, the study team evaluated the impact of AI implementation on 90-day modified Rankin Scale disability outcomes. RESULTS: Among 243 patients who met inclusion criteria, 140 were treated during the unexposed period and 103 during the exposed period. Median age for the complete cohort was 70 (IQR, 58-79) years and 122 were female (50%). Median National Institutes of Health Stroke Scale score at presentation was 17 (IQR, 11-22) and the median DTG preexposure was 100 (IQR, 81-116) minutes. In mixed-effects linear regression, implementation of the AI algorithm was associated with a reduction in DTG time by 11.2 minutes (95% CI, -18.22 to -4.2). Time from CT scan initiation to EVT start fell by 9.8 minutes (95% CI, -16.9 to -2.6). There were no differences in IV tPA treatment times nor hospital length of stay. In multivariable logistic regression adjusted for age, National Institutes of Health Stroke scale score, and the Alberta Stroke Program Early CT Score, there was no difference in likelihood of functional independence (modified Rankin Scale score, 0-2; odds ratio, 1.3; 95% CI, 0.42-4.0). CONCLUSIONS AND RELEVANCE: Automated LVO detection coupled with secure mobile phone application-based communication improved in-hospital acute ischemic stroke workflows. Software implementation was associated with clinically meaningful reductions in EVT treatment times. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05838456

14th International Symposium on Thrombolysis, Thrombectomy and Acute Stroke Therapy: proceedings and summary of discussions

The 14th International Symposium on Thrombolysis, Thrombectomy and Acute Stroke Therapy (TTST) took place in Houston, Texas on 21–22 October 2018. Attended by 150þ invited global experts, the objectives of TTST 2018 were to explore the changing landscape of acute ischemic stroke therapy and to address current controversies in thrombolysis and thrombectomy, including expanding access and systems of care with global relevance. This article summarizes the proceedings of TTST 2018. The key points of each session are listed below, the full text of presentations and discussion areavailable in the online supplement, and the full list of contributing authors appear in the Appendix at the end of this article