Finding MeVO: Identifying Intracranial Medium-Vessel Occlusions at CT Angiography.

The development of methods to detect and treat intracranial large-vessel occlusions (LVOs) has revolutionized the management of acute ischemic stroke. CT angiography (CTA) of the head and neck is effective in depicting LVOs and widely used in the evaluation of patients who have had a stroke. Ongoing efforts are now focused on the potential to detect and treat intracranial medium-vessel occlusions (MeVOs), which by definition are smaller than LVOs and thus more difficult to detect with CTA. The authors review common and variant anatomies of medium-sized cerebral arteries and the appearance of a variety of MeVOs on CT angiograms. Possible pitfalls in MeVO detection include rare anatomic variants, calcified thrombi, and stump occlusions. Current recommendations for performing CTA and ancillary methods that might aid in MeVO detection are discussed. Understanding the relevant anatomy and the variety of appearances of MeVOs aids radiologists in identifying these occlusions, particularly in the setting of urgent stroke. ©RSNA, 2024 See the invited commentary by Ospel and Nguyen in this issue.

Traumatic Cervical Cerebrovascular Injury and the Role of CTA: AJR Expert Panel Narrative Review.

Traumatic cerebrovascular injury (CVI) involving the cervical carotid and vertebral arteries is rare but can lead to stroke, hemodynamic compromise, and mortality in the absence of early diagnosis and treatment. The diagnosis of both blunt CVI (BCVI) and penetrating CVI is based on cerebrovascular imaging. The most commonly used screening criteria for BCVI include the expanded Denver criteria and the Memphis criteria, each providing varying thresholds for subsequent imaging. Neck CTA has supplanted catheter-based digital subtraction angiography as the preferred screening modality for CVI in patients with trauma. This AJR Expert Panel Narrative Review describes the current state of CTA-based cervical imaging in trauma. We review the most common screening criteria for BCVI, discuss BCVI grading scales that are based on neck CTA, describe the diagnostic performance of CTA in the context of other imaging modalities and evolving treatment strategies, and provide a practical guide for neck CTA implementation.

High-Resolution Magnetic Resonance Imaging Evidence for Intracranial Vessel Wall Inflammation Following Endovascular Thrombectomy.

Intracranial high-resolution vessel wall magnetic resonance imaging evidence of vessel wall inflammation is present following stent retriever manipulation but absent following aspiration thrombectomy. This is presented in a case of rotatory vertebral artery compression causing multiple posterior circulation infarctions requiring multiple separate aspiration and stent retriever thrombectomies.

Factors Affecting Selection of TraineE for Neurointervention (FASTEN).

BACKGROUND AND IMPORTANCE: Neurointervention is a very competitive specialty in the United States due to the limited number of training spots and the larger pool of applicants. The training standards are continuously updated to ensure solid training experiences. Factors affecting candidate(s) selection have not been fully established yet. Our study aims to investigate the factors influencing the selection process. METHODS: A 52-question survey was distributed to 93 program directors (PDs). The survey consisted of six categories: (a) Program characteristics, (b) Candidate demographics, (c) Educational credentials, (d) Personal traits, (e) Research and extracurricular activities, and (f) Overall final set of characteristics. The response rate was 59.1%. As per the programs' characteristics, neurosurgery was the most involved specialty in running the training programs (69%). Regarding demographics, the need for visa sponsorship held the greatest prominence with a mean score of 5.9 [standard deviation (SD) 2.9]. For the educational credentials, being a graduate from a neurosurgical residency and the institution where the candidate's residency training is/was scored the highest [5.4 (SD = 2.9), 5.4 (SD = 2.5), respectively]. Regarding the personal traits, assessment by faculty members achieved the highest score [8.9 (SD = 1)]. In terms of research/extracurricular activities, fluency in English had the highest score [7.2 (SD = 1.9)] followed by peer-reviewed/PubMed-indexed publications [6.4 (SD = 2.2)]. CONCLUSION: Our survey investigated the factors influencing the final decision when choosing the future neurointerventional trainee, including demographic, educational, research, and extracurricular activities, which might serve as valuable guidance for both applicants and programs to refine the selection process.

Endovascular Considerations in Traumatic Injury of the Carotid and Vertebral Arteries.

Cervical carotid and vertebral artery traumatic injuries can have a devastating natural history. This article reviews the epidemiology, mechanisms of injury, clinical presentation, and classification systems pertinent to consideration of endovascular treatment. The growing role of modern endovascular techniques for the treatment of these diseases is presented to equip endovascular surgeons with a framework for critically assessing patients presenting with traumatic cervical cerebrovascular injury.

Endovascular Thrombectomy Treatment: Beyond Early Time Windows and Small Core.

ABSTRACT: Tremendous advancements in the treatment of acute ischemic stroke in the last 25 years have been based on the principle of reperfusion in early time windows and identification of small core infarct for intravenous thrombolysis and mechanical thrombectomy. Advances in neuroimaging have made possible the safe treatment of patients with acute ischemic stroke in longer time windows and with more specific selection of patients with salvageable brain tissue. In this review, we discuss the history of endovascular stroke thrombectomy trials and highlight the neuroimaging-based trials that validated mechanical thrombectomy techniques in the extended time window with assessment of penumbral tissue. We conclude with a survey of currently open trials that seek to safely expand eligibility for this highly efficacious treatment.

Using machine learning to optimize selection of elderly patients for endovascular thrombectomy.

BACKGROUND: Endovascular thrombectomy (ET) is the standard of care for treatment of acute ischemic stroke (AIS) secondary to large vessel occlusion. The elderly population has been under-represented in clinical trials on ET, and recent studies have reported higher morbidity and mortality in elderly patients than in their younger counterparts. OBJECTIVE: To use machine learning algorithms to develop a clinical decision support tool that can be used to select elderly patients for ET. METHODS: We used a retrospectively identified cohort of 110 patients undergoing ET for AIS at our institution to train a regression tree model that can predict 90-day modified Rankin Scale (mRS) scores. The identified algorithm, termed SPOT, was compared with other decision trees and regression models, and then validated using a prospective cohort of 36 patients. RESULTS: When predicting rates of functional independence at 90 days, SPOT showed a sensitivity of 89.36% and a specificity of 89.66% with an area under the receiver operating characteristic curve of 0.952. Performance of SPOT was significantly better than results obtained using National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT score, or patients' baseline deficits. The negative predictive value for SPOT was >95%, and in patients who were SPOT-negative, we observed higher rates of symptomatic intracerebral hemorrhage after thrombectomy. With mRS scores prediction, the mean absolute error for SPOT was 0.82. CONCLUSIONS: SPOT is designed to aid clinical decision of whether to undergo ET in elderly patients. Our data show that SPOT is a useful tool to determine which patients to exclude from ET, and has been implemented in an online calculator for public use.

First attempt recanalization with ADAPT: rate, predictors, and outcome.

INTRODUCTION: The rate of first-attempt recanalization (FAR) with the newer-generation thrombectomy devices, and more specifically with aspiration devices, is not well known. Moreover, the effect of FAR on outcomes after mechanical thrombectomy is not properly understood. OBJECTIVE: To report the rate of FAR using a direct aspiration first pass technique (ADAPT), investigate the association between FAR and outcomes, and identify the predictors of FAR. METHODS: The ADAPT database was used to identify a subgroup of patients in whom FAR was achieved. Baseline characteristics, procedural, and postprocedural variables were collected. Outcome measures included 90-day modified Rankin scale (mRS) score, mortality, and hemorrhagic complications. Multivariate logistic regression was used to identify FAR predictors. RESULTS: A total of 524 patients was included of whom 178 (34.0%) achieved FAR. More patients in the FAR group than in the non-FAR group received IV tPA (46.6% vs 37.6%; p<0.05). For the functional outcome, higher proportions of patients in the FAR group achieved functional independence (mRS score 0-2; 53% vs 37%; p<0.05). Additionally, we observed lower mortality and hemorrhagic transformation rates in the FAR group than the non-FAR group. Independent predictors of FAR in the anterior circulation were pretreatment IV tPA, non-tandem occlusion, and use of larger reperfusion catheters (Penumbra, ACE 64-68). Independent predictors of FAR in the posterior circulation were diabetes, onset-to-groin time, and cardioembolic etiology. CONCLUSION: FAR was associated with better functional outcome and lower mortality rate. When ADAPT is used, a larger aspiration catheter and pretreatment IV tPA should be employed when indicated.

Outcomes of endovascular thrombectomy in the elderly: a 'real-world' multicenter study.

BACKGROUND: The efficacy of endovascular thrombectomy (ET) for acute ischemic stroke (AIS) in octogenarians is still controversial. OBJECTIVE: To evaluate, using a large multicenter cohort of patients, outcomes after ET in octogenarians compared with younger patients. METHODS: Data from prospectively maintained databases of patients undergoing ET for AIS at seven US-based comprehensive stroke centers between January 2013 and January 2018 were reviewed. Demographic, procedural, and outcome variables were collected. Outcomes included 90-day modified Rankin Scale (mRS) score, postprocedural National Institutes of Health Stroke Scale score, postprocedural hemorrhage, and mortality. Univariate and multivariate analyses were performed to assess the independent effect of age ≥80 on outcome measures. Subgroup analyses were also performed based on location of stroke, success of recanalization, or ET technique used. RESULTS: Rates of functional independence (mRS score 0-2) after ET in elderly patients were significantly lower than for younger counterparts. Age ≥80 was independently associated with increased mortality and poor outcome. Age ≥80 showed an independent negative prognostic effect on outcome even when patients were divided according to thrombectomy technique, location of stroke, or success of recanalization. Age ≥80 independently predicted higher rate of postprocedural hemorrhage, but not success of recanalization. Baseline deficit and number of reperfusion attempts, but not Thrombolysis in Cerebral Infarction score were associated with lower odds of good outcome. CONCLUSION: The large effect size of ET on AIS outcomes is significantly diminished in the elderly population when using comparable selection criteria to those used in younger counterparts. This raises concerns about the risk-benefit ratio and the cost-effectiveness of performing this procedure in the elderly before optimizing patient selection.

Systematic Review of the Literature: Best Practices.

Reviews of published scientific literature are a valuable resource that can underline best practices in medicine and clarify clinical controversies. Among the various types of reviews, the systematic review of the literature is ranked as the most rigorous since it is a high-level summary of existing evidence focused on answering a precise question. Systematic reviews employ a pre-defined protocol to identify relevant and trustworthy literature. Such reviews can accomplish several critical goals that are not easily achievable with typical empirical studies by allowing identification and discussion of best evidence, contradictory findings, and gaps in the literature. The Association of University Radiologists Radiology Research Alliance Systematic Review Task Force convened to explore the methodology and practical considerations involved in performing a systematic review. This article provides a detailed and practical guide for performing a systematic review and discusses its applications in radiology.