Simulation Methods in Acute Stroke Treatment: Current State of Affairs and Implications

Challenges to Widespread Implementation of Stroke Thrombectomy

Endovascular treatment (EVT) for acute ischemic stroke is one of the most efficacious and effective treatments in medicine, yet globally, its implementation remains limited. Patterns of EVT underutilization exist in virtually any health care system and range from a complete lack of access to selective undertreatment of certain patient subgroups. In this review, we outline different patterns of EVT underutilization and possible causes. We discuss common challenges and bottlenecks that are encountered by physicians, patients, and other stakeholders when trying to establish and expand EVT services in different scenarios and possible pathways to overcome these challenges. Lastly, we discuss the importance of implementation research studies, strategic partnerships, and advocacy efforts to mitigate EVT underutilization.

Endovascular Treatment of Medium Vessel Occlusion Stroke

Approximately one-third of acute ischemic strokes with an identifiable vessel occlusion are caused by medium vessel occlusion (MeVO), that is, nonlarge vessel occlusions that are potentially amenable to endovascular treatment (EVT). Management of patients with MeVO is challenging in many ways: detecting MeVOs can be challenging, particularly for inexperienced physicians, and in busy clinical routine, MeVOs, therefore, remain sometimes undiagnosed. While the clinical course of MeVO stroke with medical management, including intravenous thrombolysis, is by no means, benign, it is more favorable compared with large vessel occlusion. At the same time, EVT complication rates are higher, and thus, the marginal benefit of EVT beyond best medical management is expected to be smaller and more challenging to detect if it were present. Several randomized controlled trials are currently underway to investigate whether and to what degree patients with MeVO may benefit from EVT and will soon provide robust data for evidence-based MeVO EVT decision-making. In this review, we discuss different ways of defining MeVOs, strategies to optimize MeVO detection on imaging, and considerations for EVT decision-making in the setting of MeVO stroke. We discuss the technical challenges related to MeVO EVT and conclude with an overview of currently ongoing MeVO EVT trials.

Recent developments in pre-hospital and in-hospital triage for endovascular stroke treatment

Triage describes the assignment of resources based on where they can be best used, are most needed, or are most likely to achieve success. Triage is of particular importance in time-critical conditions such as acute ischemic stroke. In this setting, one of the goals of triage is to minimize the delay to endovascular thrombectomy (EVT), without delaying intravenous thrombolysis or other time-critical treatments including patients who cannot benefit from EVT. EVT triage is highly context-specific, and depends on availability of financial resources, staff resources, local infrastructure, and geography. Furthermore, the EVT triage landscape is constantly changing, as EVT indications evolve and new neuroimaging methods, EVT technologies, and adjunctive medical treatments are developed and refined. This review provides an overview of recent developments in EVT triage at both the pre-hospital and in-hospital stages. We discuss pre-hospital large vessel occlusion detection tools, transport paradigms, in-hospital workflows, acute stroke neuroimaging protocols, and angiography suite workflows. The most important factor in EVT triage, however, is teamwork. Irrespective of any new technology, EVT triage will only reach optimal performance if all team members, including paramedics, nurses, technologists, emergency physicians, neurologists, radiologists, neurosurgeons, and anesthesiologists, are involved and engaged. Thus, building sustainable relationships through continuous efforts and hands-on training forms an integral part in ensuring rapid and efficient EVT triage.

Metric based virtual simulation training for endovascular thrombectomy improves interventional neuroradiologists' simulator performance

OBJECTIVE

Metric based virtual reality simulation training may enhance the capability of interventional neuroradiologists (INR) to perform endovascular thrombectomy. As pilot for a national simulation study we examined the feasibility and utility of simulated endovascular thrombectomy procedures on a virtual reality (VR) simulator.

METHODS

Six INR and four residents participated in the thrombectomy skill training on a VR simulator (Mentice VIST 5G). Two different case-scenarios were defined as benchmark-cases, performed before and after VR simulator training. INR performing endovascular thrombectomy clinically were also asked to fill out a questionnaire analyzing their degree of expectation and general attitude towards VR simulator training.

RESULTS

All participants improved in mean total procedure time for both benchmark-cases. Experts showed significant improvements in handling errors (case 2), a reduction in contrast volume used (case 1 and 2), and fluoroscopy time (case 1 and 2). Novices showed a significant improvement in steps finished (case 2), a reduction in fluoroscopy time (case 1), and radiation used (case 1). Both, before and after having performed simulation training the participating INR had a positive attitude towards VR simulation training.

CONCLUSION

VR simulation training enhances the capability of INR to perform endovascular thrombectomy on the VR simulator. INR have generally a positive attitude towards VR simulation training. Whether the VR simulation training translates to enhanced clinical performance will be evaluated in the ongoing Norwegian national simulation study.

Virtual reality simulation training in stroke thrombectomy centers with limited patient volume-Simulator performance and patient outcome

BACKGROUND

Virtual reality simulation training may improve the technical skills of interventional radiologists when establishing endovascular thrombectomy at limited-volume stroke centers. The aim of this study was to investigate whether the technical thrombectomy performance of interventional radiologists improved after a defined virtual reality simulator training period. As part of the quality surveillance of clinical practice, we also assessed patient outcomes and thrombectomy quality indicators at the participating centers.

METHODS

Interventional radiologists and radiology residents from three thrombectomy-capable stroke centers participated in a five months thrombectomy skill-training curriculum on a virtual reality simulator. The simulator automatically registered procedure time, the number of predefined steps that were correctly executed, handling errors, contrast volume, fluoroscopy time, and radiation dose exposure. The design was a before-after study. Two simulated thrombectomy cases were used as pretest and posttest cases, while seven other cases were used for training. Utilizing the Norwegian Stroke Register, we investigated clinical results in thrombectomy during the study period.

RESULTS

Nineteen interventional radiologists and radiology residents participated in the study. The improvement between pretest and posttest cases was statistically significant for all outcome measures in both simulated cases, except for the contrast volume used in one case. Clinical patient outcomes in all three centers were well within the recommendations from multi-society consensus guidelines.

CONCLUSION

Performance on the virtual reality simulator improved after training. Virtual reality simulation may improve the learning curve for interventional radiologists in limited-volume thrombectomy centers. No correlation alleged, the clinical data indicates that the centers studied performed thrombectomy in accordance with guideline-recommended standards.

Team is brain: leveraging EHR audit log data for new insights into acute care processes

OBJECTIVE

To determine whether novel measures of contextual factors from multi-site electronic health record (EHR) audit log data can explain variation in clinical process outcomes.

MATERIALS AND METHODS

We selected one widely-used process outcome: emergency department (ED)-based team time to deliver tissue plasminogen activator (tPA) to patients with acute ischemic stroke (AIS). We evaluated Epic audit log data (that tracks EHR user-interactions) for 3052 AIS patients aged 18+ who received tPA after presenting to an ED at three Northern California health systems (Stanford Health Care, UCSF Health, and Kaiser Permanente Northern California). Our primary outcome was door-to-needle time (DNT) and we assessed bivariate and multivariate relationships with six audit log-derived measures of treatment team busyness and prior team experience.

RESULTS

Prior team experience was consistently associated with shorter DNT; teams with greater prior experience specifically on AIS cases had shorter DNT (minutes) across all sites: (Site 1: -94.73, 95% CI: -129.53 to 59.92; Site 2: -80.93, 95% CI: -130.43 to 31.43; Site 3: -42.95, 95% CI: -62.73 to 23.17). Teams with greater prior experience across all types of cases also had shorter DNT at two sites: (Site 1: -6.96, 95% CI: -14.56 to 0.65; Site 2: -19.16, 95% CI: -36.15 to 2.16; Site 3: -11.07, 95% CI: -17.39 to 4.74). Team busyness was not consistently associated with DNT across study sites.

CONCLUSIONS

EHR audit log data offers a novel, scalable approach to measure key contextual factors relevant to clinical process outcomes across multiple sites. Audit log-based measures of team experience were associated with better process outcomes for AIS care, suggesting opportunities to study underlying mechanisms and improve care through deliberate training, team-building, and scheduling to maximize team experience.

Can Interventional Cardiologists Help Deliver the UK Mechanical Thrombectomy Interventional Programme for Patients with Acute Ischaemic Stroke? A Discussion Paper from the British Cardiovascular Interventional Society Stroke Thrombectomy Focus Group

There is a willingness among UK interventional cardiologists to contribute to provision of a 24/7 mechanical thrombectomy (MT) service for all suitable stroke patients if given the appropriate training. This highly effective intervention remains unavailable to the majority of patients who might benefit, partly because there is a limited number of trained specialists. As demonstrated in other countries, interdisciplinary working can be the solution and an opportunity to achieve this is outlined in this article.

Simulation-Based Assessment of Graduate Neurology Trainees' Performance Managing Acute Ischemic Stroke

BACKGROUND AND OBJECTIVES

Multidisciplinary acute stroke teams improve acute ischemic stroke management but may hinder trainees' education which in turn may contribute to poorer outcomes in community hospitals upon graduation. Our goal was to assess graduate neurology trainee performance independent of a multi-disciplinary stroke team in the management of acute ischemic stroke, tissue plasminogen activator (tPA)-related hemorrhage, and cerebral herniation syndrome.

METHODS

In this prospective, observational, single-center simulation-based study, participants (sub-interns to attending physicians) managed a patient with acute ischemic stroke followed by tPA-related hemorrhagic conversion leading to cerebral herniation. Critical actions were developed by a modified Delphi approach based on relevant American Heart Association guidelines and the Neurocritical Care Society's Emergency Neurological Life Support protocols. The primary outcome measure was graduate neurology trainees' critical action item sum score. We sought validity evidence to support our findings by comparing trainees' performance across four levels of training.

RESULTS

Fifty-three trainees (including 31 graduate neurology trainees) and five attending physicians completed the simulation. The mean sum of critical actions completed by graduate neurology trainees was 15/22 (68%). Ninety percent of graduate neurology trainees properly administered tPA, 84% immediately stopped tPA infusion following patient deterioration, but only 55% reversed tPA according to guidelines. There was a moderately strong effect of level of training on critical action sum score (level 1 mean score [standard deviation (SD)] = 7.2 (2.8) vs. level 2 mean score (SD) = 12.3 (2.6) vs. level 3 mean score (SD) = 13.3 (2.2) vs. level 4 mean score (SD) = 16.3 (2.4), p < .001, R² = 0.54).

DISCUSSION

Graduate neurology trainees reassuringly perform well in initial management of acute ischemic stroke, but frequently make errors in the treatment of hemorrhagic transformation after thrombolysis, suggesting the need for more education surrounding this low frequency, high-acuity event. High-fidelity simulation holds promise as an assessment tool for acute stroke management performance.

A clinical perspective on endovascular stroke treatment biomechanics

Acute ischemic stroke (AIS) is caused by blockage of an arterial blood vessel in the brain by a thrombus, which interrupts oxygen supply to the brain parenchyma. The goal of endovascular stroke treatment (mechanical thrombectomy) is to restore blood flow as quickly and completely as possible. There are numerous factors that influence endovascular treatment success. They can be broadly grouped into a) factors related to blood vessels, b) factors related to the thrombus, c) factors related to endovascular treatment technique and tools and d) operator-related factors. While blood vessel and tgthro thrombus-related factors are mostly non-modifiable in the acute setting, operator and technique-related factors can be modified, and extensive research is currently being done to investigate the complex interplay of all these variables, and to optimize the modifiable factors to the maximum possible extent. In this review, we will describe these factors and how they interact with each other in detail, and outline some of their practical implications. We will conclude with a short summary and outlook on future directions for optimizing endovascular treatment success.

Cost-effectiveness of a quality improvement project, including simulation-based training, on reducing door-to-needle times in stroke thrombolysis

BACKGROUND

Rapid revascularisation in acute ischaemic stroke is crucial to reduce its total burden including societal costs. A quality improvement (QI) project that included streamlining the stroke care pathway and simulation-based training was followed by a significant reduction in median door-to-needle time (27 to 13 min) and improved patient outcomes after stroke thrombolysis at our centre. Here, we present a retrospective cost-effectiveness analysis of the QI project.

METHODS

Costs for implementing and sustaining QI were assessed using recognised frameworks for economic evaluations. Effectiveness was calculated from previously published outcome measures. Cost-effectiveness was presented as incremental cost-effectiveness ratios including costs per minute door-to-needle time reduction per patient, and costs per averted death in the 13-month post-intervention period. We also estimated incremental cost-effectiveness ratios for a projected 5-year post-intervention period and for varying numbers of patients treated with thrombolysis. Furthermore, we performed a sensitivity analysis including and excluding costs of unpaid time.

RESULTS

All costs including fixed costs for implementing the QI project totalled US$44 802, while monthly costs were US$2141. We calculated a mean reduction in door-to-needle time of 13.1 min per patient and 6.36 annual averted deaths. Across different scenarios, the estimated costs per minute reduction in door-to-needle time per patient ranged from US$13 to US$29, and the estimated costs per averted death ranged from US$4679 to US$10 543.

CONCLUSIONS

We have shown that a QI project aiming to improve stroke thrombolysis treatment at our centre can be implemented and sustained at a relatively low cost with increasing cost-effectiveness over time. Our work builds on the emerging theory and practice for economic evaluations in QI projects and simulation-based training. The presented cost-effectiveness data might help guide healthcare leaders planning similar interventions.

Integrating New Staff into Endovascular Stroke-Treatment Workflows in the COVID-19 Pandemic

A health care crisis such as the coronavirus disease 2019 (COVID-19) pandemic requires allocation of hospital staff and resources on short notice. Thus, new and sometimes less experienced team members might join the team to fill in the gaps. This scenario can be particularly challenging in endovascular stroke treatment, which is a highly specialized task that requires seamless cooperation of numerous health care workers across various specialties and professions. This document is intended for stroke teams who face the challenge of integrating new team members into endovascular stroke-treatment workflows during the COVID-19 pandemic or any other global health care emergency. It discusses the key strategies for smooth integration of new stroke-team members in a crisis situation: 1) transfer of key knowledge (simple take-home messages), 2) open communication and a nonjudgmental atmosphere, 3) strategic task assignment, and 4) graded learning and responsibility. While these 4 key principles should generally be followed in endovascular stroke treatment, they become even more important during health care emergencies such as the COVID-19 pandemic, when health care professionals have to take on new and additional roles and responsibilities in challenging working environments for which they were not specifically trained.

Clinical considerations and assessment of risk factors when choosing endovascular thrombectomy for acute stroke

INTRODUCTION

The advent of endovascular thrombectomy (EVT) has been a game changer for the management of acute ischemic stroke due to large vessel occlusion. However, the selection of suitable candidates for EVT remains a significant challenge.

AREAS COVERED

This review focuses on the clinical, radiological, and procedural considerations for EVT in acute stroke that assist in optimal patient selection.

EXPERT OPINION

All patients presenting with significant clinical deficits with treatable occlusions, who have salvageable brain tissue at presentation might benefit from treatment up to twenty-four hours from symptom onset. Neuroimaging tools form the backbone for this decision making.