WSO - January 2024 - 58

1180434
WSO
International Journal of StrokeMujanovic et al.
Review
No-reflow phenomenon in stroke
patients: A systematic literature review
and meta-analysis of clinical data
Adnan Mujanovic1 , Felix Ng2,3 , Thomas R Meinel4,
Tomas Dobrocky1, Eike I Piechowiak1, Christoph C Kurmann1,5,
David J Seiffge4, Susanne Wegener6, Roland Wiest1,
Lukas Meyer7, Jens Fiehler7, Jean Marc Olivot8 , Marc Ribo9,
Thanh N Nguyen10 , Jan Gralla1, Bruce CV Campbell2,
Urs Fischer4,11 and Johannes Kaesmacher1
Abstract
Background: The no-reflow phenomenon refers to the absence of microvascular reperfusion despite macrovascular
reperfusion.
Aim: The aim of this analysis was to summarize the available clinical evidence on no-reflow in patients with acute ischemic
stroke.
Methods: A systematic literature review and a meta-analysis of clinical data on definition, rates, and impact of the noreflow
phenomenon after reperfusion therapy was carried out. A predefined research strategy was formulated according
to the Population, Intervention, Comparison, and Outcome (PICO) model and was used to screen for articles in
PubMed, MEDLINE, and Embase up to 8 September 2022. Whenever possible, quantitative data were summarized using
a random-effects model.
Results: Thirteen studies with a total of 719 patients were included in the final analysis. Most studies (n = 10/13) used
variations of the Thrombolysis in Cerebral Infarction scale to evaluate macrovascular reperfusion, whereas microvascular
reperfusion and no-reflow were mostly assessed on perfusion maps (n = 9/13). In one-third of stroke patients with
successful macrovascular reperfusion (29%, 95% confidence interval (CI), 21-37%), the no-reflow phenomenon was
observed. Pooled analysis showed that no-reflow was consistently associated with reduced rates of functional independence
(odds ratio (OR), 0.21, 95% CI, 0.15-0.31).
Conclusion: The definition of no-reflow varied substantially across studies, but it appears to be a common phenomenon.
Some of the no-reflow cases may simply represent remaining vessel occlusions, and it remains unclear whether no-reflow
1Department of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Inselspital, University of Bern, Bern, Switzerland
2Department of Medicine and Neurology, Melbourne Brain Centre at the Royal Melbourne Hospital, University of Melbourne, Parkville, VIC,
Australia
3Department of Neurology, Austin Health, Heidelberg, VIC, Australia
4Department of Neurology, University Hospital Bern, Inselspital, University of Bern, Bern, Switzerland
5Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Inselspital, University of Bern, Bern, Switzerland
6Department of Neurology, University Hospital Zürich, University of Zürich, Zürich, Switzerland
7Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
8Department of Neurology and Clinical Investigation Center, Toulouse University Hospital, Toulouse, France
9Department of Neurology, University Hospital Vall d'Hebron, Barcelona, Spain
10Department of Neurology, Boston Medical Center, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA
11Department of Neurology, University Hospital Basel, University of Basel, Basel, Switzerland
Corresponding author:
Johannes Kaesmacher, Department of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Inselspital, University of Bern,
Freiburgstrasse 10, 3001 Bern, Switzerland.
Email: johannes.kaesmacher@insel.ch
International Journal of Stroke, 19(1)
International Journal of Stroke
2024, Vol. 19(1) 58 -67
© 2023 World Stroke Organization
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DOI: 10.1177/17474930231180434
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WSO - January 2024

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