Drive-the-doctor paradigm in acute ischaemic stroke for improving regional stroke care networks: a cost-effectiveness analysis

BACKGROUND AND OBJECTIVE

In a drive-the-doctor (DD) paradigm, an interventionalist travels from a comprehensive stroke centre (CSC) to primary stroke centres (PSCs) to perform endovascular thrombectomy (EVT) for acute ischaemic stroke due to large vessel occlusion (LVO). The DD paradigm may reduce time delays from onset to recanalisation. This study aimed to analyse the cost-effectiveness of the DD paradigm versus a drip-and-ship (DS) paradigm, where LVO patients are transferred from PSCs to a CSC for EVT in the northern Netherlands.

DESIGN

Economic evaluation was performed using a simulation model combined with a decision tree and a Markov model.

SETTING

Stroke centres in the northern Netherlands.

PARTICIPANTS

A hypothetical cohort of 100 000 LVO patients with an average age of 70 years.

INTERVENTIONS

Two strategies were tested, including the DD paradigm with one upgraded PSC and the DD paradigm with two upgraded PSCs.

MAIN OUTCOME MEASURES

Total costs and quality-adjusted life years (QALYs) were measured over a 15-year time horizon from a Dutch healthcare provider perspective. An incremental cost-effectiveness ratio (ICER) of €50 000 was used as a willingness-to-pay threshold. One-way sensitivity, probabilistic sensitivity and scenario analyses (interventionalist transportation by car, ambulance and helicopter) were conducted to examine parameter uncertainty.

RESULTS

The DD paradigm using car as a transport modality and two PSCs was the optimal strategy, resulting in the lowest ICER. This strategy provided an additional 0.13 QALYs at incremental costs of €2367, yielding an ICER of €18 306 compared with current practice. The DD paradigm with two PSCs reduced ICERs compared with the scenario with one PSC when varying transportation modalities (car, ambulance and helicopter). Probabilistic sensitivity analyses showed that the DD paradigm with two PSCs using car was preferred in 72% of 10 000 Monte Carlo simulations.

CONCLUSIONS

The DD paradigm appeared cost-effective for LVO patients and may be considered a promising evolution for a regional stroke network.

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.

Outcome of endovascular stroke therapy in a large mandatory stroke-registry

BACKGROUND

Endovascular stroke treatment (EST) has become the standard treatment for patients with stroke due to large vessel occlusion, especially in earlier time windows. Only few data from population-based registries on effectiveness of EST have been published.

METHODS

Baden-Wuerttemberg is the third largest state in Germany in terms of area and population and has a structured stroke concept since 1998 which includes mandatory collection of quality assurance data. In 2018 and 2019, 3820 of 39,168 ischemic stroke patients (9.8%) were treated by EST (age median 78 y, NIHSS median 14). We analyzed the clinical outcome of these patients determined with the modified Rankin Scale (mRS) at discharge from the hospital or with the initiation of palliative therapy using logistic regression analysis with adjustment for the mRS at admission, additive IVT, age, and NIHSS.

RESULTS

The probability of an excellent clinical outcome (mRS 0 or 1 at discharge) and for a good clinical outcome (mRS 0-2) were significantly higher in EST-patients (odds-ratio (OR) 1.27; 95% confidence interval (95% CI) 1.13-1.43, and OR of 1.15 (95% CI 1.04-1.28). Also, the regression model showed an advantage for EST-patients with less frequent 'decision for palliative care' (OR 0.87; 95% CI 0.78-0.98). Sensitivity analysis adjusting for intracranial vessel occlusion as further factor showed similar results.

CONCLUSION

Our data suggest that EST can be of benefit also for an area-wide unselected stroke population, in a large German federal state with sometimes long distance to the next thrombectomy center.

'Drive the doctor' for endovascular thrombectomy in a rural area: a simulation study

BACKGROUND

Patients who present in a primary stroke center (PSC) with ischemic stroke are usually transferred to a comprehensive stroke center (CSC) in case of a large vessel occlusion (LVO) for endovascular thrombectomy (EVT) treatment, the so-called 'drip-and-ship' (DS) model. The 'drive-the-doctor' (DD) model modifies the DS model by allowing mobile interventionalists (MIs) to transfer to an upgraded PSC acting as a thrombectomy capable stroke center (TSC), instead of transferring patients to a CSC. Using simulation we estimated time savings and impact on clinical outcome of DD in a rural region.

METHODS

Data from EVT patients in northern Netherlands was prospectively collected in the MR CLEAN Registry between July 2014 - November 2017. A Monte Carlo simulation model of DS patients served as baseline model. Scenarios included regional spread of TSCs, pre-hospital patient routing to 'the nearest PSC' or 'nearest TSC', MI's notification after LVO confirmation or earlier prehospital, and MI's transport modalities. Primary outcomes are onset to groin puncture (OTG) and predicted probability of favorable outcome (PPFO) (mRS 0-2).

RESULTS

Combining all scenarios OTG would be reduced by 28-58 min and PPFO would be increased by 3.4-7.1%. Best performing and acceptable scenario was a combination of 3 TSCs, prehospital patient routing based on the RACE scale, MI notification after LVO confirmation and MI's transfer by ambulance. OTG would reduce by 48 min and PPFO would increase by 5.9%.

CONCLUSIONS

A DD model is a feasible scenario to optimize acute stroke services for EVT eligible patients in rural regions. Key design decisions in implementing the DD model for a specific region are regional spread of TSCs, patient routing strategy, and MI's notification moment and transport modality.

Access to and application of recanalizing therapies for severe acute ischemic stroke caused by large vessel occlusion

BACKGROUND

Groundbreaking study results since 2014 have dramatically changed the therapeutic options in acute therapy for severe ischemic stroke caused by large vessel occlusion (LVO). The scientifically proven advances in stroke imaging and thrombectomy techniques have allowed to offer the optimal version or combination of best medical and interventional therapy to the selected patient, yielding favorable or even excellent clinical outcomes within time windows unheard of before. The provision of the best possible individual therapy has become a guideline-based gold standard, but remains a great challenge. With geographic, regional, cultural, economic and resource differences worldwide, optimal local solutions have to be strived for.

AIM

This standard operation procedure (SOP) is aimed to give a suggestion of how to give patients access to and apply modern recanalizing therapy for acute ischemic stroke caused by LVO.

METHOD

The SOP was developed based on current guidelines, the evidence from the most recent trials and the experience of authors who have been involved in the above-named development at different levels.

RESULTS

This SOP is meant to be a comprehensive, yet not too detailed template to allow for freedom in local adaption. It comprises all relevant stages in providing care to the patient with severe ischemic stroke such as suspicion and alarm, prehospital acute measures, recognition and grading, transport, emergency room workup, selective cerebral imaging, differential treatment by recanalizing therapies (intravenous thrombolysis, endovascular stroke treatmet, or combined), complications, stroke unit and neurocritical care.

CONCLUSIONS

The challenge of giving patients access to and applying recanalizing therapies in severe ischemic stroke may be facilitated by a systematic, SOP-based approach adapted to local settings.

Clinical outcome, recanalization success, and time metrics in drip-and-ship vs. drive-the-doctor: A retrospective analysis of the HEI-LU-Stroke registry

Purpose

This study aimed at comparing clinical outcome, recanalization success and time metrics in the “drip and ship” (DS) vs. “drive the doctor” (DD) concept in a comparable setting.

Methods

This is a retrospective analysis of thrombectomy registries of a comprehensive stroke center (CSC) and a thrombectomy-capable stroke center (TSC). Patients, who were transferred from the TSC to the CSC, were classified as DS. Patients treated at the TSC by an interventionalist transferred from the CSC were classified as DD. Good outcome was defined as mRS 0–2 or equivalent to premorbid mRS at discharge. Recanalization (TICI 2b-3 or equivalent) and time metrics were compared in both groups.

Results

In total, 295 patients were included, of which 116 (39.3%) were treated in the DS concept and 179 (60.7%) in the DD concept. Good clinical outcome was similarly achieved in DS and DD (DS 25.0% vs. DD 31.3%, P = 0.293). mRS on discharge (DS median 4, DD median 4, P = 0.686), NIHSS improvement (DS median 4, DD median 5, P = 0.582) and NIHSS on discharge (DS median 9, DD median 7, P = 0.231) were similar in both groups. Successful reperfusion was achieved similarly in DS (75.9%) and DD as well (81.0%, P = 0.375). Time from onset to reperfusion (median DS 379 vs. DD 286 min, P = 0.076) and time from initial imaging to reperfusion were longer in DS compared to DD (median DS 246 vs. DD 162 min, P < 0.001).

Conclusion

The DD concept is time saving while achieving similar clinical outcome and recanalization results.

Thrombectomy-Capable Stroke Centre-A Key to Acute Stroke Care System Improvement? Retrospective Analysis of Safety and Efficacy of Endovascular Treatment in Cardiac Cathlab

The optimal structure of the acute ischaemic stroke treatment network is unknown and eagerly sought. To make it most effective, different treatment and transportation strategies have been developed and investigated worldwide. Since only a fraction of acute stroke patients with large vessel occlusion are treated, a new entity-thrombectomy-capable stroke centre (TCSC)-was introduced to respond to the growing demand for timely endovascular treatment. The purpose of this study was to present the early experience of the first 70 patients treated by mechanical means in a newly developed cardiac Cathlab-based TCSC. The essential safety and efficacy measures were recorded and compared with those reported in the invasive arm of the HERMES meta-analysis-the largest published dataset on the subject. We found no significant differences in terms of clinical and safety outcomes, such as early neurological recovery, level of functional independence at 90 days, symptomatic intracranial haemorrhage, parenchymal haematoma type 2, and mortality. These encouraging results obtained in the small endovascular centre may be an argument for the introduction of the TCSC into operating stroke networks to increase patient access to timely treatment and to improve clinical outcomes.

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.

Influences of different referral modes on clinical outcomes after endovascular therapy for acute ischemic stroke

Background and purpose

As endovascular thrombectomy (EVT) is time-dependent, it is crucial to refer patients promptly. Current referral modes include Mothership (MS), Drip and Ship (DS) and Drive the Doctor (DD). The purpose of this study was to investigate the influences of different referral modes on the clinical outcomes of patients with acute ischemic stroke after EVT. 

Methods

A total of 349 patients from 15 hospitals between April 2017 and March 2020 were enrolled. The primary outcomes include poor outcome (modified Rankin Scale score of 3 to 6), symptomatic intracranial hemorrhage transformation (sICH), mortality and cost. Regression analysis was used to assess the association of referral modes with poor outcome, sICH, mortality and cost in acute ischemic stroke patients.

Results

Among the 349 patients, 83 were in DD group (23.78%), 85 in MS group (24.36%) and 181 in DS group (51.86%). There were statistically significant differences in intravenous thrombolysis, onset-to-door time, onset-to-puncture time, puncture-to-recanalization time, door-to-puncture time, door-to-recanalization time, and cost among the DD, MS, and DS groups (59.04% vs 35.29% vs 33.15%, P<0.001; 90 vs 166 vs 170 minutes, P<0.001; 230 vs 270 vs 270 minutes, P<0.001; 82 vs 54 vs 51 minutes, P<0.001; 110 vs 85 vs 96 minutes, P=0.004; 210 vs 146 vs 150 minutes, P<0.001; 64258 vs 80041 vs 70750 Chinese Yuan, P=0.018). In terms of sICH, mortality and poor outcome, there was no significant difference among the DD, MS, and DS groups (22.89% vs 18.82% vs 19.34%, P=0.758; 24.10% vs 24.71% vs 29.83%, P=0.521; 64.47% vs 64.71% vs 68.51%, P=0.827). The results of multiple regression analysis indicated that there was no independent correlation between different referral modes regarding sICH (OR_MS: 0.50, 95%CI: 0.18, 1.38, P=0.1830; OR_DS: 0.47, 95%CI: 0.19, 1.16, P=0.1000), mortality (OR_MS: 0.56, 95%CI: 0.19, 1.67, P=0.2993; OR_DS: 0.65, 95%CI: 0.25, 1.69, P=0.3744) and poor outcome (OR_MS: 0.61, 95%CI: 0.25, 1.47, P=0.2705; OR_DS: 0.53, 95%CI: 0.24, 1.18, P=0.1223). However, there was a correlation between MS group and cost (β=30449.73, 95%CI: 11022.18, 49877.29; P=0.0023). The multiple regression analysis on patients finally admitted in comprehensive stroke center (MS+DS) versus patients finally admitted in primary stroke center (DD) showed that DD mode was independently associated with lower costs (β=-19438.86, 95%CI: -35977.79, -2899.94; P=0.0219).

Conclusion

There was no independent correlation between three referral modes and sICH, mortality, poor outcome correspondingly. Different referral modes can be implemented in clinical practice according to the situations encountered. Compared to MS and DS modes, DD mode is more economical.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02751-w.

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.

Effect of "drip-and-ship" and "drip-and-drive" on endovascular treatment of acute ischemic stroke with large vessel occlusion: a single-center retrospective study

BACKGROUND

Patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) were usually transferred from a primary stroke center (PSC) to a comprehensive stroke center (CSC) for endovascular treatment (drip-and-ship [DS]), while driving the doctor from a CSC to a PSC to perform a procedure is an alternative strategy (drip-and-drive [DD]).

PURPOSE

To compare the efficacy and prognosis of the two strategies.

MATERIAL AND METHODS

From February 2017 to June 2019, 62 patients with LVO received endovascular treatment via the DS and DD models and were retrospectively analyzed from the stroke alliance based on our CSC. Primary endpoint was door-to-reperfusion (DTR) time. Secondary endpoints included puncture-to-recanalization (PTR) time, modified Thrombolysis in Cerebral Infarction (mTICI) rates at the end of the procedure, and modified Rankin Scale (mRS) at 90 days.

RESULTS

Forty-one patients received the DS strategy and 21 patients received the DD strategy. The DTR time was significantly longer in the DS group compared to the DD group (315.5 ± 83.8 min vs. 248.6 ± 80.0 min; P < 0.05), and PTR time was shorter (77.2 ± 35.9 min vs. 113.7 ± 69.7 min; P = 0.033) compared with the DD group. Successful recanalization (mTICI 2b/3) was achieved in 89% (36/41) of patients in the DS group and 86% (18/21) in the DD group (P = 1.000). Favorable functional outcomes (mRS 0-2) were observed in 49% (20/41) of patients in the DS group and 71% (15/21) in the DD group at 90 days (P = 0.089).

CONCLUSION

Compared with the DS strategy, the DD strategy showed more effective and a trend of better clinical outcomes for AIS patients with LVO.

Clinical Outcome After Endovascular Thrombectomy in 3 Triage Concepts: A Prospective, Observational Study (NEUROSQUAD)

BACKGROUND AND PURPOSE

NEUROSQUAD (Stroke Treatment: Quality and Efficacy in Different Referral Systems) is a prospective, observational, bicenter study comparing 3 triage pathways in endovascular stroke treatment: mothership, drip and ship (DS), and transferring a neurointerventionalist to a remote hospital for thrombectomy (drive the doctor [DD]).

METHODS

Patients with anterior circulation stroke and premorbid modified Rankin Scale (mRS) score 0-3 who underwent thrombectomy within 24 hours after stroke onset were included. Primary outcome measure was good clinical outcome defined as 90-day mRS score 0-2 or clinical recovery to the status before stroke onset (ie, equal premorbid mRS and 90-day mRS). Secondary outcome measures were successful reperfusion, National Institutes of Health Stroke Scale at discharge, and mRS shift.

RESULTS

In total, 360 patients were included in this study, of whom 111 patients (30.8%) were in the mothership group, 204 patients (56.7%) were in the DS group, and 45 patients (12.5%) were in the DD group. Good clinical outcome was achieved similarly in all three groups (mothership, 45.9%; DS, 43.1%; DD, 40.0%; P=0.778). Likewise, frequency of successful reperfusion was similar in all three groups (mothership, 86.5%; DS, 85.3%; DD, 82.2%; P=0.714). There was no significant difference among the groups regarding the National Institutes of Health Stroke Scale at discharge (P=0.115) and mRS shift (P=0.342). In the multivariate analysis, triage concept was not an independent predictor of good outcome (unadjusted odds ratio, 0.89 [CI, 0.64-1.23]; P=0.479).

CONCLUSIONS

Our data suggest that clinical outcome after thrombectomy is similar in mothership, DS, and DD. Hence, DD can be a valuable triage option in acute stroke treatment.

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

BACKGROUND

Endovascular treatment of large vessel occlusion in acute ischemic stroke patients is difficult to establish in remote areas, and time dependency of treatment effect increases the urge to develop health care concepts for this population.

SUMMARY

Current strategies include direct transportation of patients to a comprehensive stroke center (CSC) ("mothership model") or transportation to the nearest primary stroke center (PSC) and secondary transfer to the CSC ("drip-and-ship model"). Both have disadvantages. We propose the model "flying intervention team." Patients will be transported to the nearest PSC; if telemedically identified as eligible for thrombectomy, an intervention team will be acutely transported via helicopter to the PSC and endovascular treatment will be performed on site. Patients stay at the PSC for further stroke unit care. This model was implemented at a telestroke network in Germany. Fifteen remote hospitals participated in the project, covering 14,000 km2 and a population of 2 million. All have well established telemedically supported stroke units, an angiography suite, and a helicopter pad. Processes were defined individually for each hospital and training sessions were implemented for all stroke teams. An exclusive project helicopter was installed to be available from 8 a.m. to 10 p.m. during 26 weeks per year. Key Messages: The model of the flying intervention team is likely to reduce time delays since processes will be performed in parallel, rather than consecutively, and since it is quicker to move a medical team rather than a patient. This project is currently under evaluation (clinicaltrials NCT04270513).

[Remote proctoring in neuroradiological interventions]

Hintergrund

Endovaskuläre Verfahren haben einen festen Platz bei der Behandlung von Hirngefäßerkrankungen, z. B. die Thrombektomie beim Schlaganfall. Die ständige Weiterentwicklung der hierbei verwendeten Materialien (z. B. Katheter und Stents) fordert von den behandelnden Ärzten ein permanentes Lernen.

Fragestellung

Technische Hilfsmöglichkeiten zur Unterstützung bei neuen neuroendovaskulären Verfahren.

Material und Methode

Integration von Streamingtechnologien in das Ausbildungskonzept von Neuroradiologen.

Ergebnisse

Die Übertragung angiographischer Aufnahmen auf einen entfernten Computerarbeitsplatz in Echtzeit ist mittels spezifischer Streamingtechnologie ortsunabhängig möglich. Hierdurch kann ein neuroendovaskulärer Spezialist geographisch entfernte Interventionalisten bei der Durchführung eines Kathetereingriffes am Gehirn beraten, die Handhabung der verwendeten Materialien überblicken und bei Bedarf anleiten (Remote-Proctoring).

Schlussfolgerungen

Insbesondere bei Notfalleingriffen und während Reisebeschränkungen kann durch Zuschaltung eines weiteren neuroendovaskulären Spezialisten per Livestreaming die Patientensicherheit erhöht werden.

Number of Patients with Ischemic Stroke did not Decline in a Regional Stroke Unit After the Implementation of Mechanical Thrombectomy

OBJECTIVES

Since the implementation of mechanical thrombectomy (MT) in 2015 for patients with ischemic stroke and large-vessel occlusion, the question arose as to whether patients should be primarily admitted to the nearest regional stroke unit (SU) for prompt intravenous thrombolysis (IVT) or to a more distant supraregional SU performing MT, to avoid secondary-transfer delays in MT. Although an evidence-based answer is still lacking, a discrepant discussion with potential consequences for the regional flow of stroke patients arose. We aimed to assess if MT implementation was associated with the number and characteristics of patients with stroke/transient ischemic attack (TIA) admitted to a regional SU not offering endovascular treatment.

MATERIALS AND METHODS

Patients with acute stroke/TIA treated at the Klinikum Main-Spessart Lohr, Germany, in 2013/2014 or 2017/2018 were included in this retrospective study. Data were derived from the clinical information system and mandatory stroke quality assessment. We assessed the catchment area using a region-based approach. For each region, the number of patients treated in our hospital, including data regarding clinical severity, demographic characteristics, and changes over time, were analyzed.

RESULTS

The number of patients with acute stroke/TIA increased from 890 (2013/2014) to 1016 (2017/2018). Aggregated demographic and clinical data of the whole catchment area showed no differences between 2013/2014 and 2017/2018 (P > 0.05) besides duration of hospitalization (P < 0.01), IVT rate (P < 0.01), and secondary transfer for MT. A region-based analysis revealed an increase in younger and more severely affected patients admitted from the periphery of the catchment area between 2013/2014 and 2017/2018.

CONCLUSION

Despite the implementation of MT in the supraregional SUs around our regional SU (not offering MT), more patients with stroke/TIA were admitted to our hospital, especially younger and more severely affected patients, from the border regions of the catchment area.

Mobile Interventional Stroke Team Model Improves Early Outcomes in Large Vessel Occlusion Stroke

Background and Purpose:

Triage of patients with emergent large vessel occlusion stroke to primary stroke centers followed by transfer to comprehensive stroke centers leads to increased time to endovascular therapy. A Mobile Interventional Stroke Team (MIST) provides an alternative model by transferring a MIST to a Thrombectomy Capable Stroke Center (TSC) to perform endovascular therapy. Our aim is to determine whether the MIST model is more time-efficient and leads to improved clinical outcomes compared with standard drip-and-ship (DS) and mothership models.

Methods:

This is a prospective observational cohort study with 3-month follow-up between June 2016 and December 2018 at a multicenter health system, consisting of one comprehensive stroke center, 4 TSCs, and several primary stroke centers. A total of 228 of 373 patients received endovascular therapy via 1 of 4 models: mothership with patient presentation to a comprehensive stroke center, DS with patient transfer from primary stroke center or TSC to comprehensive stroke center, MIST with patient presentation to TSC and MIST transfer, or a combination of DS with patient transfer from primary stroke center to TSC and MIST. The prespecified primary end point was initial door-to-recanalization time and secondary end points measured additional time intervals and clinical outcomes at discharge and 3 months.

Results:

MIST had a faster mean initial door-to-recanalization time than DS by 83 minutes ( P <0.01). MIST and mothership had similar median door-to-recanalization times of 192 minutes and 179 minutes, respectively ( P =0.83). A greater proportion had a complete recovery (National Institutes of Health Stroke Scale of 0 or 1) at discharge in MIST compared with DS (37.9% versus 16.7%; P <0.01). MIST had 52.8% of patients with modified Rankin Scale of ≤2 at 3 months compared with 38.9% in DS ( P =0.10).

Conclusions:

MIST led to significantly faster initial door-to-recanalization times compared with DS, which was comparable to mothership. This decrease in time has translated into improved short-term outcomes and a trend towards improved long-term outcomes.

Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03048292.

Pathway Design for Acute Stroke Care in the Era of Endovascular Thrombectomy: A Critical Overview of Optimization Efforts

The efficacy of intravenous thrombolysis and endovascular thrombectomy (EVT) for acute ischemic stroke is highly time dependent. Optimal organization of acute stroke care is therefore important to reduce treatment delays but has become more complex after the introduction of EVT as regular treatment for large vessel occlusions. There is no singular optimal organizational model that can be generalized to different geographic regions worldwide. Current dominant organizational models for EVT include the drip-and-ship- and mothership model. Guidelines recommend routing of suspected patients with stroke to the nearest intravenous thrombolysis capable facility; however, the choice of routing to a certain model should depend on regional stroke service organization and individual patient characteristics. In general, design approaches for organizing stroke care are required, in which 2 key strategies could be considered. The first entails the identification of interventions within existing organizational models for optimizing timely delivery of intravenous thrombolysis and/or EVT. This includes adaptive patient routing toward a comprehensive stroke center, which focuses particularly on prehospital triage tools; bringing intravenous thrombolysis or EVT to the location of the patient; and expediting services and processes along the stroke pathway. The second strategy is to develop analytical or simulation model-based approaches enabling the design and evaluation of organizational models before their implementation. Organizational models for acute stroke care need to take regional and patient characteristics into account and can most efficiently be assessed and optimized through the application of model-based approaches.

Time Metrics to Endovascular Thrombectomy in 3 Triage Concepts

Background and Purpose—

NEUROSQUAD (Stroke Treatment: Quality and Efficacy in Different Referral Systems) is a prospective, observational, bi-center study comparing 3 triage pathways in endovascular stroke treatment: mothership (MS), drip and ship (DS) and transferring a neurointerventionalist to a remote hospital for thrombectomy (drive the doctor [DD]).

Methods—

Between February and October 2018, all stroke patients undergoing thrombectomy at 2 university hospitals and 2 associated remote hospitals were included. Primary outcome measures were time from onset to groin puncture and time from imaging to groin puncture. Secondary outcome measures were time from onset to imaging and time from onset to thrombolysis.

Results—

In total, 440 patients were included (mothership 32.3%, DS 55.9%, DD 11.8%). Median time from onset to groin puncture (168 minutes) and time from imaging to groin puncture (51 minutes) were the shortest in the mothership group. Time from onset to groin puncture (DD median 225 versus DS median 300 minutes; P =0.001) and time from imaging to groin puncture (DD median 118 versus DS median 172 minutes; P <0.001) were shorter in the DD group compared with DS. Time from onset to imaging was similar among mothership, DS, and DD ( P =0.363). In patients receiving thrombolysis, time from onset to needle was similar among the groups ( P =0.620).

Conclusions—

The NEUROSQUAD study adds evidence that DD may be a feasible alternative to DS, leading to shorter delay between symptom onset and groin puncture. Both are time-wise inferior compared with mothership, though.

Training and Supervision of Thrombectomy by Remote Live Streaming Support (RESS) : Randomized Comparison Using Simulated Stroke Interventions

PURPOSE

Stroke patients are excluded from expeditious thrombectomy in regions lacking neurointerventional specialists. An audiovisual online streaming system was tested, allowing a neurointerventional specialist located at a neurovascular center to supervise and instruct a thrombectomy performed at a distant hospital without being physically present (remote streaming support [RESS]).

METHODS

In total, 36 thrombectomy procedures were performed on a Mentice endovascular simulator by six radiologists not specialized in neurointerventions. Each radiologist was challenged with six different endovascular simulation scenarios under alternating conventional local support (specialist inside the room [LOS]) and RESS, which was performed using an advanced live streaming platform.

RESULTS

Both support modes led to a median of 2 attempts (interquartile range [IQR] 2.0-2.0 each) until successful recanalization. There was no statistically significant difference in time from first catheter insertion to recanalization between LOS (median 24.9 min, IQR 21.0-31.5 min) and RESS (23.9 min, IQR 21.7-28.7 min, p = 0.89). The percentage of thrombi covered by the stent-retriever and average speed when retrieving the stent-retriever (3.7 mm/s, IQR 3.25-5.35 mm/s vs. 3.6 mm/sec, IQR 2.5-4.7) were similar in both groups. Fluoroscopy time did not differ (19.0 min, IQR 16.9-23.5 min vs. 19.9 min, IQR 15.9-23.5 min) with a trend towards increased median amounts of contrast medium used under RESS (62.9 ml vs. 43.1 ml; p = 0.055).

CONCLUSION

This study confirmed the feasibility of RESS for thrombectomy procedures in a simulated environment. This serves as basis for future studies planned to analyze the effectiveness of RESS in a real-world environment and to test if it improves the learning curve of interventionalists with limited thrombectomy experience in remote areas.

Drip and ship for mechanical thrombectomy within the Neurovascular Network of Southwest Bavaria

Objective

To determine feasibility and safety of stroke care organization within our Neurovascular Network of Southwest Bavaria (NEVAS) in a rural area with distances of up to 100 kilometers, we compared patients who underwent mechanical thrombectomy (MT) in large vessel occlusion admitted directly to our center (direct to center [DTC]) to patients who were transferred for MT via NEVAS (drip and ship [DS]).

Methods

This is a retrospective analysis of prospectively collected data of all MT patients between January 2015 and May 2018. Successful recanalization was defined as a thrombolysis in cerebral infarction score of 2b-3. Symptomatic intracerebral hemorrhage (sICH) was defined according to European Cooperative Acute Stroke Study 3. Modified Rankin Scale (mRS) score of 0–2 at 3 months indicated good outcome.

Results

MT was performed in 410 patients: 221 DTC and 189 DS. Median NIH Stroke Scale (NIHSS) score was 16 and premorbid mRS score was 0. Thrombolysis was applied in 62.2% with the same time from symptom onset in both groups (94.5 vs 95 minutes). Successful recanalization (79.3% vs 77.8%) and NIHSS score reduction from admission to discharge (16–7 vs 17–6) were comparable. Time delay from onset to revascularization was 96 minutes in DS (212 vs 308 minutes, p = 0.001). At follow-up, DTC patients had a trend to better outcome (33.5% vs 24.3%, p = 0.056). Neither sICH (6.3% vs 5.9%, p = 0.840) nor mortality (31.2% vs 34.4%, p = 0.387) differed between the groups.

Conclusion

DS patients benefit from MT without relevant safety concerns, but with a trend to unfavorable outcome compared to DTC patients. These results suggest that DS is suitable to provide MT in rural areas where DTC is not possible.

Endovascular Treatment of Acute Ischemic Stroke

PURPOSE OF REVIEW

Endovascular thrombectomy (ET), the standard of treatment for emergent large vessel occlusion (ELVO) strokes, has been subject to rigorous efforts to further improve its usage and delivery for optimised patient outcomes. This review aims to provide an outline and discussion about the recently established and emerging recommendations regarding endovascular treatment of stroke.

RECENT FINDINGS

The indications for ET have expanded continually, with perfusion imaging now enabling selection of patients presenting 6-24 h after last-known-well, and improved device and operator proficiency allowing treatment of M2-MCA occlusions and tandem occlusions. Further inclusion of paediatric patients and patients with larger infarct core or milder stroke symptoms for ET has been proposed; however, this remains unproven. This growing applicability is supported by more efficient systems of care, employing modern techniques such as telemedicine, mobile stroke units and helicopter medical services. Ongoing debate exists regarding thrombolytic agent, thrombectomy technique, anaesthesia method and the role of advanced neuroimaging, with upcoming RCTs expected to provide clarification. The journey to further improving the efficacy of ET has advanced and diversified rapidly over recent years, involving improved patient selection, increased utility of advanced neuroimaging and ongoing device redevelopment, within the setting of more efficient, streamlined systems of care. This dynamic and ongoing influx of evidence-based refinements is key to further optimising outcomes for ELVO patients.

[Mothership or drip and ship?]

BACKGROUND

The scientific evidence of the high efficacy of endovascular stroke treatment in large vessel occlusion (LVO) led to this treatment being accepted as the gold standard in these patients.

OBJECTIVE

This review article presents the various organizational models for thrombectomy and analyzes which model is preferred under which circumstances.

MATERIAL AND METHODS

In an analysis of the recent scientific literature the models for optimizing patient transport (drip and ship or mothership) and optimizing the availability of interventionalists (drip and drive or remote mentoring) are presented and compared. In addition, considerations are made on thrombectomy rates and the prevalence of LVOs and the construction of organizational models.

RESULTS

If the location of the stroke patient is just as far from or closer to a comprehensive stroke center (CSC) than a primary stroke center (PSC), the patient should be transported directly to the CSC by mothership. If, on the other hand, a PSC is closer to the stroke site than a CSC and the time after the onset of symptoms lies within the lysis time window, this decision depends on many variables.

CONCLUSION

Based on the unambiguous data situation, no recommendations can currently be made for a generally superior organizational model.

Electronic Alberta Stroke Program Early CT score change and functional outcome in a drip-and-ship stroke service

Background

Debate continues as to whether patients with acute ischemic stroke with (suspected) large vessel occlusion benefit from direct referral versus secondary transportation.

Aims

To analyze the change in early infarct signs, collaterals, and acute ischemia volume and their association with transfer time and functional outcome.

Methods

We retrospectively analyzed consecutive transfers between 2013 and 2016 for patients with anterior circulation stroke transported from referring hospitals to our center as potential candidates for thrombectomy. Alberta Stroke Programme Early CT Scores (ASPECTS) were automatically calculated on external and in-house CT using the Brainomix e-ASPECTS software, and collaterals were assessed using the e-CTA tool. Functional status after stroke using the modified Rankin scale (mRS) was obtained.

Results

102 patients with CT scans both at the referring hospital and our center were identified. During patient transfer, e-ASPECTS declined by a median of 1 point (0–2). Functional outcome correlated with the change in e-ASPECTS (decline, n=54) (Spearman rs=0.322, 95% CI 0.131 to 0.482, p=0.001). The median image-to-image time was 149 min (IQR 113–190), but did not correlate with change in e-ASPECTS (p=0.754) and mRS score at 3 months (p=0.25). Preserved good collateral status assessed at the comprehensive stroke center was associated with better functional outcome (rs=−0.271, 95% CI −0.485 to −0.037, p=0.02).

Conclusions

Patient transfer in a drip-and-ship network was associated with declines in e-ASPECTS associated with worse functional outcome. Image-to-image time did not influence this association, but worsening collateral status did.