Ultra-Long Transfers for Endovascular Thrombectomy—Mission Impossible?: The Australia-New Zealand Experience

Abstract

BACKGROUND: Endovascular thrombectomy (EVT) access in remote areas is limited. Preliminary data suggest that long distance transfers for EVT may be beneficial; however, the magnitude and best imaging strategy at the referring center remains uncertain. We hypothesized that patients transferred >300 miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0–2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS. METHODS: This is a retrospective analysis of patients transferred from 31 referring hospitals >300 miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021). RESULTS: There were 131 patients; the median age was 64 [53–74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12–22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1–3] versus 3 [1–6] in the patients selected with noncontrast CT+CT angiography, P =0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01–0.19]; P <0.01). CONCLUSIONS: In selected patients transferred >300 miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.

Pre-hospital telestroke and expanded hyper-acute telestroke network solutions to reduce geographic inequities: a brief review from the South Pacific

“…Training of local specialists is inconceivable in many locations and may be challenging to maintain if case volumes are small although should be explored wherever feasible. Alternatively, ultra-long transfers are possible and can still result in favorable outcomes as shown in an Australia-New Zealand case series (Garcia-Esperon et al, 2023). While this study described within country transfers, some of the reported distances were similar to distances between Pacific Islands and the nearest thrombectomy center in a neighboring country making this primarily a policy maker issue around cost recovery and medicolegal regulations.…”

Impact of stroke imaging selection modality on endovascular thrombectomy outcomes in the early and extended time windows: A meta‐analysis

“…Following the removal of duplicates and screening of titles and abstracts, 165 studies were subjected to full‐text review. To avoid heterogeneity in outcome estimates, 14 studies (Bouslama et al., 2017 ; Chalouhi et al., 2013 ; Dekker et al., 2021 ; Fischer et al., 2022 ; Garcia‐Esperon et al., 2023 ; Kim & Kim, 2020 ; Koneru et al., 2018 ; Krebs et al., 2022 ; Leslie et al., 2016 ; Lin et al., 2020 ; Prabhakaran et al., 2014 ; Provost et al., 2019 ; Sheth et al., 2013 ; Vagal et al., 2016 ) that compared the outcomes of patients who received EVT with the use of advanced imaging versus basic imaging were excluded from the meta‐analysis due to variability in treatment time windows. Furthermore, a study (Kim et al, 2019 ) that compared the results of diagnosis using advanced imaging versus basic imaging in patients with AIS‐LVO undergoing endovascular therapy, including arterial thrombolysis, was also excluded.…”

Introducing the Concept of Sanctuary Sites in Ischemic Stroke

“…Sparing of these regions may account for some of the cases of improved functional outcomes. [9][10][11][12] Augmenting cerebral blood flow through pharmacological methods 13 may, in the future, play an important role in the management of patients transferred long distances 14 for endovascular treatment. Maintaining blood flow through collaterals before revascularization can reduce overall infarct size and improve clinical outcomes.…”

“…13 Therefore, understanding the locations of potential sanctuary sites may guide decision-making when access to thrombectomy is delayed. 14…”