The "Flying Intervention Team": A Novel Stroke Care Concept for Rural Areas

Physician Transfer Versus Patient Transfer for Mechanical Thrombectomy in Patients With Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Physician transfer is an alternate option to patient transfer for expedient performance of mechanical thrombectomy in patients with acute ischemic stroke.

METHODS AND RESULTS

We conducted a systematic review to identify studies that evaluate the effect of physician transfer in patients with acute ischemic stroke who undergo mechanical thrombectomy. A search of PubMed, Scopus, and Web of Science was undertaken, and data were extracted. A statistical pooling with random-effects meta-analysis was performed to examine the odds of reduced time interval between stroke onset and recanalization, functional independence, death, and angiographic recanalization. A total of 12 studies (11 nonrandomized observational studies and 1 nonrandomized controlled trial) were included, with a total of 1894 patients. Physician transfer was associated with a significantly shorter time interval between stroke onset and recanalization with a pooled mean difference estimate of -62.08 (95% CI, -112.56 to -11.61]; P=0.016; 8 studies involving 1419 patients) with high between-study heterogeneity in the estimates (I2=90.6%). The odds for functional independence at 90 days were significantly higher (odds ratio, 1.29 [95% CI, 1.00-1.66]; P=0.046; 7 studies with 1222 patients) with physician transfer with low between-study heterogeneity (I2=0%). Physician transfer was not associated with higher odds of near-complete or complete angiographic recanalization (odds ratio, 1.18 [95% CI, 0.89-1.57; P=0.25; I2=2.8%; 11 studies with 1856 subjects).

CONCLUSIONS

Physician transfer was associated with a significant reduction in the mean of time interval between symptom onset and recanalization and increased odds for functional independence at 90 days with physician transfer compared with patient transfer among patients who undergo mechanical thrombectomy.

Aeromedical Transport for Critically Ill Patients

Aeromedical transport (AMT) is an integral part of healthcare systems worldwide. In this article, the personnel and equipment required, associated safety considerations, and evidence supporting the use of AMT is reviewed, with an emphasis on helicopter emergency medical services (HEMS). Indications for HEMS as guideded by the Air Medical Prehospital Triage Score are presented. Lastly, physiologic considerations, which are important to both AMT crews and receiving clinicians, are reviewed.

Global stroke statistics 2023: Availability of reperfusion services around the world

BACKGROUND

Disparities in the availability of reperfusion services for acute ischemic stroke are considerable globally and require urgent attention. Contemporary data on the availability of reperfusion services in different countries are used to provide the necessary evidence to prioritize where access to acute stroke treatment is needed.

AIMS

To provide a snapshot of published literature on the provision of reperfusion services globally, including when facilitated by telemedicine or mobile stroke unit services.

METHODS

We searched PubMed to identify original articles, published up to January 2023 for the most recent, representative, and relevant patient-level data for each country. Keywords included thrombolysis, endovascular thrombectomy and telemedicine. We also screened reference lists of review articles, citation history of articles, and the gray literature. The information is provided as a narrative summary.

RESULTS

Of 11,222 potentially eligible articles retrieved, 148 were included for review following de-duplications and full-text review. Data were also obtained from national stroke clinical registry reports, Registry of Stroke Care Quality (RES-Q) and PRE-hospital Stroke Treatment Organization (PRESTO) repositories, and other national sources. Overall, we found evidence of the provision of intravenous thrombolysis services in 70 countries (63% high-income countries (HICs)) and endovascular thrombectomy services in 33 countries (68% HICs), corresponding to far less than half of the countries in the world. Recent data (from 2019 or later) were lacking for 35 of 67 countries with known year of data (52%). We found published data on 74 different stroke telemedicine programs (93% in HICs) and 14 active mobile stroke unit pre-hospital ambulance services (80% in HICs) around the world.

CONCLUSION

Despite remarkable advancements in reperfusion therapies for stroke, it is evident from available patient-level data that their availability remains unevenly distributed globally. Contemporary published data on availability of reperfusion services remain scarce, even in HICs, thereby making it difficult to reliably ascertain current gaps in the provision of this vital acute stroke treatment around the world.

Interdisciplinary Rendez-Vous Approach in Endovascular Stroke Treatment: A New Concept to Accelerate Mechanical Thrombectomy in Primary Stroke Centers

PURPOSE

Prompt endovascular treatment of patients with stroke due to intracranial Large Vessel Occlusion (LVO) is a major challenge in rural areas because neurointerventionalists are usually not available. As a result, treatment is delayed, and clinical outcomes are worse compared with patients primarily treated in comprehensive stroke centers (CSC). To address this problem, we present a concept in which interdisciplinary, on-site endovascular treatment is performed in a Primary Stroke Center (PSC) by a team of interventional neuroradiologists and cardiologists: the Rendez-Vous approach.

METHODS

Thirty-five patients with LVO who underwent interdisciplinary thrombectomy on-site at the PSC as part of the Rendez-Vous concept were compared with 72 patients who were transferred from a PSCs to the CSC for thrombectomy when diagnosed with LVO in terms of temporal sequences and clinical outcomes.

RESULTS

Patients treated on-site at the PSC as part of the Rendez-Vous approach were managed as successfully and without an increase in complication rates compared with patients treated secondarily at a CSC (91.7% successful interventions in Rendez-Vous vs. 87.3% in control group, p = 0.57). The time from diagnosis of LVO to groin puncture was reduced by mean 74.3 min with the Rendez-Vous concept (p < 0.01). Regarding the clinical outcome, a functionally independent status was achieved in 45.5% in the Rendez-Vous group and in 22.6% in the control group (p = 0.029).

CONCLUSION

Thanks to interdisciplinary teamwork between cardiology and interventional neuroradiology in local PSCs, times to successful reperfusion can be reduced. This has a potentially positive impact on the clinical outcome of stroke patients.

Telestroke network to robotic telestroke network: How to upgrade regional stroke care to include remote robotics?

Objective

Selected patients with large vessel occlusion (LVO) strokes can benefit from endovascular therapy (EVT). However, the effectiveness of EVT is largely dependent on how quickly the patient receives treatment. Recent technological developments have led to the first neurointerventional treatments using robotic assistance, opening up the possibility of performing remote stroke interventions. Existing telestroke networks provide acute stroke care, including remote administration of intravenous thrombolysis (IVT). Therefore, the introduction of remote EVT in distant stroke centers requires an adaptation of the existing telestroke networks. The aim of this work was to propose a framework for centers that are potential candidates for telerobotics according to the resources currently available in these centers.

Methods

In this paper, we highlight the future challenges for including remote robotics in telestroke networks. A literature review provides potential solutions.

Results

Existing telestroke networks need to determine which centers to prioritize for remote robotic technologies based on objective criteria and cost-effectiveness analysis. Organizational challenges include regional coordination and specific protocols. Technological challenges mainly concern telecommunication networks.

Conclusions

Specific adaptations will be necessary if regional telestroke networks are to include remote robotics. Some of these can already be put in place, which could greatly help the future implementation of the technology.

Prehospital Stroke Care Part 1: Emergency Medical Services and the Stroke Systems of Care

Acute stroke care begins before hospital arrival, and several prehospital factors are critical in influencing overall patient care and poststroke outcomes. This topical review provides an overview of the state of the science on prehospital components of stroke systems of care and how emergency medical services systems may interact in the system to support acute stroke care. Topics include layperson recognition of stroke, prehospital transport strategies, networked stroke care, systems for data integration and real-time feedback, and inequities that exist within and among systems.

[Prehospital stroke treatment in German-speaking countries]

Background

The prognosis of stroke patients can be improved by adherence to clinical guidelines.

Objective

To analyse the current state of organisation of prehospital stroke treatment in Germany, Austria and Switzerland with a focus on guideline adherence.

Materials and methods

All medical directors of emergency medical services (MDEMS) in Germany (n = 178), Austria (n = 9) and Switzerland (n = 32) were invited to complete an anonymous online survey (unipark.com, Tivian XI GmbH, Cologne, Germany) which was available for 10 weeks from April-June 2020. Participants were asked for information regarding structural organisation, clinical treatment and strategic/tactical aspects.

Results

The survey was completed 69 times and 65 datasets were analysed (4 participants without MDEMS status): 73.8% (n = 48) were MDEMS from Germany, 15.4% (n = 10) from Switzerland and 10.8% from Austria (n = 7). The survey results show relevant differences in the infrastructure of and the approach to prehospital stroke treatment. Standard operating procedures for stroke treatment were in place in 93.3% (n = 61) of the EMS areas. Furthermore, 37% (n = 24) of the EMS areas differentiated between stroke with mild and severe symptoms and 15.4% (n = 10) used specific scores for the prehospital prediction of large vessel occlusion strokes (LVOS).

Conclusions

Our data highlight the heterogeneity of prehospital stroke treatment in Germany, Austria and Switzerland. Consistent use of appropriate scores for LVOS prediction and a higher adherence to recent clinical guideline in general are measures that should be taken to optimise the prehospital treatment of stroke patients.

Mothership vs. drip-and-ship: evaluation of initial treatment strategies for acute ischemic stroke in a well-developed network of specialized hospitals

PURPOSE

Two strategies of initial patient care exist in endovascular thrombectomy (ET) depending on the site of initial admission: the mothership (MS) and drip-and-ship (DnS) principles. This study compares both strategies in regard to patient outcome in a local network of specialized hospitals.

METHODS

Two-hundred-and-two patients undergoing ET in anterior circulation ischemic stroke between June 2016 and May 2018 were enrolled. Ninety two patients were directly admitted to our local facility (MS), One-hundred-and-ten were secondarily referred to our facility. Group comparisons between admission strategies in three-months modified Rankin Scale (mRS), Maas Score and Alberta-Stroke-Program-Early-computed-tomography-score (ASPECTS), National-Institutes-of-Health-Stroke-Scale (NIHSS), age and onset-to-recanalization-time were performed. Correlation between admission strategy and mRS was calculated. A binary logistic regression model was computed including mRS as dependent variable.

RESULTS

There were neither significant group differences in three-months mRS between MS and DnS nor significant correlations. Patients tended to achieve a better outcome with DnS. Collateralization status differed between MS and DnS (p = 0.003) with better collateralization in DnS. There were no significant group differences in NIHSS or ASPECTS but in onset-to-recanalization-time (p < 0.001) between MS and DnS. Binary logistic regression showed a high explanation of variance of mRS but no significant results for admission strategy.

CONCLUSIONS

Functional outcome in patients treated with ET is comparable between the MS and DnS principles. Tendentially better outcome in the DnS subgroup may be explained by selection bias due to a higher willingness to apply ET in patients with worse baseline conditions (e.g. worse collateralization), if patients undergoing MS are already on site.

Feasibility, Safety, and Technical Success of the Flying Intervention Team in Acute Ischemic Stroke

Background

Prompt endovascular care of patients with ischemic stroke due to large vessel occlusion (LVO) remains a major challenge in rural regions as primary stroke centers (PSC) usually cannot provide neuro-interventional services. Objective The core content of the Flying Intervention Team (FIT) project is to perform thrombectomy on-site at a local PSC after the neuro-interventionalist has been transported via helicopter to the target hospital. An important and so far unanswered question is whether mechanical thrombectomy can be performed as safely and successfully on-site as in a specialized comprehensive stroke center (CSC).

Methods

Comparison of 100 FIT thrombectomies on site in 14 different PSCs with 128 control thrombectomies at 1 CSC (79 drip-and-ship, 49 mothership) performed by a single interventionalist with respect to technical-procedural success parameters, procedural times, and complications.

Results

There were no significant differences between the two groups in terms of technical success (95.0% successful interventions in FIT group vs. 94.5% in control group, p = 0.60) and complications (3% major complications in FIT vs. 1.6% in control group, p = 0.47). Regarding time from onset to groin puncture, there was no difference between FIT and the entire control group (182 vs. 183 min, p = 0.28), but a trend in favor of FIT compared with the drip-and-ship control subgroup (182 vs. 210 min, p = 0.096).

Conclusions

Airborne neuro-interventional thrombectomy service is a feasible approach for rural regions. If performed by experienced neuro-interventionalists, technical success and complication rates are comparable to treatment in a specialized neuro-interventional department.

The pioneering past and cutting-edge future of interventional neuroradiology

This review provides a thorough understanding of the developments in the field of interventional neuroradiology (INR). A concise overview of the pioneering past and current state of this field is presented first, followed by a greater emphasis on its future. Five main aspects predicted to undergo significant developments are identified and discussed. These include changes in 'education and training', 'clinical practice and logistics', 'devices and equipment', 'techniques and procedures', and 'relevant diagnostic imaging'. INR is at the crossroads of neuroradiology, neurosurgery, neurology, and the neurosciences. To progress we must value the uniqueness and vitality of this multidisciplinary aspect. While minimal access techniques offer very good anatomical accessibility to treat multiple pathologies of the central nervous system, it is also important to recognise its limitations. Medical, surgical, and radiosurgery modalities retain an important role in the management of some complex neuropathology. This review is certainly not exhaustive of all ongoing and predicted developments, but it is an important update for INR specialists and other interested professionals.

Health economic evaluation of the 'Flying Intervention Team' as a novel stroke care concept for rural areas: study protocol of the TEMPiS-GÖA study

INTRODUCTION

Providing comprehensive stroke care poses major organisational and financial challenges to the German healthcare system. The quasi-randomised TEMPiS-Flying Intervention Team (TEMPiS-FIT) study aims to close the gap in the treatment of patients who had ischaemic stroke in rural areas of Southeast Bavaria by flying a team of interventionalists via helicopter directly to patients in the regional TEMPiS hospitals instead of transporting the patients to the next comprehensive stroke centre. The objective of the present paper is to describe the methods for the economic evaluation (TEMPiS-Gesundheitsökonomische Analyse (TEMPiS-GÖA)) alongside the TEMPiS-FIT study to determine whether the new form of care is cost-effective compared with standard care.

METHODS AND ANALYSIS

The within-trial cost-effectiveness analysis (CEA) and cost-utility analysis (CUA) will be performed from a statutory health insurance perspective as well as from a societal perspective over the time horizon of 12 months after the patients' hospital discharge. Direct costs from outpatient and inpatient care are collected from routine data of the participating health insurance funds, while medical and non-medical costs from a patient's perspective are retrieved from primary data collected during the TEMPiS-FIT study and follow-up questionnaires. Results will be presented as incremental cost-effectiveness ratio and incremental cost-utility ratio quantifying the incremental costs and health benefits compared with standard care practice. The outcome of the CEA will be measured in costs per minute reduction in mean process time to thrombectomy. The outcome of the CUA will be presented as costs per quality-adjusted life year gained.

ETHICS AND DISSEMINATION

Ethical approval for the TEMPiS-FIT study was granted by the Bavarian State Medical Association Ethics Committee (# 17056). Results will be disseminated via reports, presentations of the results in publications and at conferences and on the TEMPiS website.

TRIAL REGISTRATION NUMBER

German Clinical Trials Register DRKS00023885. Registered on 2 July 2021 - retrospectively registered.

Association Between Use of a Flying Intervention Team vs Patient Interhospital Transfer and Time to Endovascular Thrombectomy Among Patients With Acute Ischemic Stroke in Nonurban Germany

IMPORTANCE

The benefit of endovascular thrombectomy (EVT) for acute ischemic stroke is highly time-dependent, and it is challenging to expedite treatment for patients in remote areas.

OBJECTIVE

To determine whether deployment of a flying intervention team, compared with patient interhospital transfer, is associated with a shorter time to endovascular thrombectomy and improved clinical outcomes for patients with acute ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

This was a nonrandomized controlled intervention study comparing 2 systems of care in alternating weeks. The study was conducted in a nonurban region in Germany including 13 primary telemedicine-assisted stroke centers within a telestroke network. A total of 157 patients with acute ischemic stroke for whom decision to pursue thrombectomy had been made and deployment of flying intervention team or patient interhospital transfer was initiated were enrolled between February 1, 2018, and October 24, 2019. The date of final follow-up was January 31, 2020.

EXPOSURES

Deployment of a flying intervention team for EVT in a primary stroke center vs patient interhospital transfer for EVT to a referral center.

MAIN OUTCOMES AND MEASURES

The primary outcome was time delay from decision to pursue thrombectomy to start of the procedure in minutes. Secondary outcomes included functional outcome after 3 months, determined by the distribution of the modified Rankin Scale score (a disability score ranging from 0 [no deficit] to 6 [death]).

RESULTS

Among the 157 patients included (median [IQR] age, 75 [66-80] y; 80 [51%] women), 72 received flying team care and 85 were transferred. EVT was performed in 60 patients (83%) in the flying team group vs 57 (67%) in the transfer group. Median (IQR) time from decision to pursue EVT to start of the procedure was 58 (51-71) minutes in the flying team group and 148 (124-177) minutes in the transfer group (difference, 90 minutes [95% CI, 75-103]; P < .001). There was no significant difference in modified Rankin Scale score after 3 months between patients in the flying team (n = 59) and transfer (n = 57) groups who received EVT (median [IQR] score, 3 [2-6] vs 3 [2-5]; adjusted common odds ratio for less disability, 1.91 [95% CI, 0.96-3.88]; P = .07).

CONCLUSIONS AND RELEVANCE

In a nonurban stroke network in Germany, deployment of a flying intervention team to local stroke centers, compared with patient interhospital transfer to referral centers, was significantly associated with shorter time to EVT for patients with acute ischemic stroke. The findings may support consideration of a flying intervention team for some stroke systems of care, although further research is needed to confirm long-term clinical outcomes and to understand applicability to other geographic settings.

Transferring neurointerventionalists saves time compared with interhospital transfer of stroke patients for endovascular thrombectomy: a collaborative pooled analysis of 1001 patients (EVEREST)

BACKGROUND

Interhospital transfer of stroke patients (drip and ship concept) is associated with longer treatment times compared with primary admission to a comprehensive stroke center (mothership concept). In recent years, studies on a novel concept of performing endovascular thrombectomy (EVT) at external hospitals (EXT) by transferring neurointerventionalists, instead of patients, have been published. This collaborative study aimed at answering the question of whether EXT saves time in the workflow of acute stroke treatment across various geographical regions.

METHODS

This was a patient level pooled analysis of one prospective observational study and four retrospective cohort studies, the EVEREST collaboration (EndoVascular thrombEctomy at Referring and External STroke centers). Time from initial stroke imaging to EVT (vascular puncture) was compared in mothership, drip and ship, and EXT concepts.

RESULTS

In total, 1001 stroke patients from various geographical regions who underwent EVT due to large vessel occlusion were included. These were divided into mothership (n=162, 16.2%), drip and ship (n=458, 45.8%), and EXT (n=381, 38.1%) cohorts. The median time periods from onset to EVT (195 min vs 320 min, p<0.001) and from imaging to EVT (97 min vs 184 min, p<0.001) in EXT were significantly shorter than for drip and ship thrombectomy concept.

CONCLUSIONS

This pooled analysis of the EVEREST collaboration adds evidence that performing EVT at external hospitals can save time compared with drip and ship across various geographical regions. We encourage conducting randomized controlled trials comparing both triage concepts.

Shifting acute stroke management to the prehospital setting

PURPOSE OF REVIEW

The earlier the treatment, the better the outcomes after acute ischemic stroke. Optimizing prehospital care bears potential to shorten treatment times. We here review the recent literature on mothership vs. drip-and-ship as well as mobile stroke unit concepts.

RECENT FINDINGS

Mobile stroke units result in the shortest onset-to-treatment times in mostly urban settings.

SUMMARY

Future research should focus on further streamlining processes around mobile stroke units, especially improving dispatch algorithms and improve referral for endovascular therapy.

National implementation of reperfusion for acute ischaemic stroke in England: How should services be configured? A modelling study

Objectives

To guide policy when planning thrombolysis (IVT) and thrombectomy (MT) services for acute stroke in England, focussing on the choice between ‘mothership’ (direct conveyance to an MT centre) and ‘drip-and-ship’ (secondary transfer) provision and the impact of bypassing local acute stroke centres.

Design

Outcome-based modelling study.

Setting

107 acute stroke centres in England, 24 of which provide IVT and MT (IVT/MT centres) and 83 provide only IVT (IVT-only units).

Participants

242,874 emergency admissions with acute stroke over 3 years (2015–2017).

Intervention

Reperfusion delivered by drip-and-ship, mothership or ‘hybrid’ models; impact of additional travel time to directly access an IVT/MT centre by bypassing a more local IVT-only unit; effect of pre-hospital selection for large artery occlusion (LAO).

Main outcome measures

Population benefit from reperfusion, time to IVT and MT, admission numbers to IVT-only units and IVT/MT centres.

Results

Without pre-hospital selection for LAO, 94% of the population of England live in areas where the greatest clinical benefit, assuming unknown patient status, accrues from direct conveyance to an IVT/MT centre. However, this policy produces unsustainable admission numbers at these centres, with 78 out of 83 IVT-only units receiving fewer than 300 admissions per year (compared to 3 with drip-and-ship). Implementing a maximum permitted additional travel time to bypass an IVT-only unit, using a pre-hospital test for LAO, and selecting patients based on stroke onset time, all help to mitigate the destabilising effect but there is still some significant disruption to admission numbers, and improved selection of patients suitable for MT selectively reduces the number of patients who would receive IVT at IVT-only centres, challenging the sustainability of IVT expertise in IVT-only centres.

Conclusions

Implementation of reperfusion for acute stroke based solely on achieving the maximum population benefit potentially leads to destabilisation of the emergency stroke care system. Careful planning is required to create a sustainable system, and modelling may be used to help planners maximise benefit from reperfusion while creating a sustainable emergency stroke care system.

[Telemedicine in stroke-pertinent to stroke care in Germany]

BACKGROUND AND OBJECTIVE

Telemedical stroke networks improve stroke care and provide access to time-dependent acute stroke treatment in predominantly rural regions. The aim is a presentation of data on its utility and regional distribution.

METHODS

The working group on telemedical stroke care of the German Stroke Society performed a survey study among all telestroke networks.

RESULTS

Currently, 22 telemedical stroke networks including 43 centers (per network: median 1.5, interquartile range, IQR, 1-3) as well as 225 cooperating hospitals (per network: median 9, IQR 4-17) operate in Germany and contribute to acute stroke care delivery to 48 million people. In 2018, 38,211 teleconsultations (per network: median 1340, IQR 319-2758) were performed. The thrombolysis rate was 14.1% (95% confidence interval 13.6-14.7%) and transfer for thrombectomy was initiated in 7.9% (95% confidence interval 7.5-8.4%) of ischemic stroke patients. Financial reimbursement differs regionally with compensation for telemedical stroke care in only three federal states.

CONCLUSION

Telemedical stroke care is utilized in about 1 out of 10 stroke patients in Germany. Telemedical stroke networks achieve similar rates of thrombolysis and transfer for thrombectomy compared with neurological stroke units and contribute to stroke care in rural regions. Standardization of network structures, financial assurance and uniform quality measurements may further strengthen the importance of telestroke networks in the future.