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Endovascular therapy for acute ischemic stroke with distal medium vessel occlusion: a systematic review and meta-analysis
  1. Enver De Wei Loh1,
  2. Keith Zhi Xian Toh1,
  3. Gabriel Yi Ren Kwok2,
  4. Yao Hao Teo3,
  5. Yao Neng Teo3,
  6. Claire Goh3,
  7. Nicholas L Syn4,
  8. Andrew Fu-Wah Ho5,6,
  9. Ching-Hui Sia3,7,
  10. Vijay Kumar Sharma3,8,
  11. Benjamin YQ Tan3,8,
  12. Leonard LL Yeo3,8
  1. 1Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
  2. 2Institute of Health Sciences Education, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
  3. 3Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
  4. 4Department of Surgery, National University Health System, Singapore
  5. 5Department of Emergency Medicine, Singapore General Hospital, Singapore
  6. 6Pre-hospital & Emergency Research Centre, Duke-National University of Singapore Medical School, Singapore
  7. 7Department of Cardiology, National University Heart Centre, Singapore
  8. 8Division of Neurology, Department of Medicine, National University Hospital, Singapore
  1. Correspondence to Dr Leonard LL Yeo, Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore; leonardyeoll{at}


Aims Endovascular therapy (EVT) for distal medium vessel occlusions (DMVOs) is a potential frontier of acute ischemic stroke (AIS) treatment, but its efficacy against best medical therapy (BMT) remains unknown. We performed a systematic review and meta-analysis evaluating the efficacy and safety of EVT versus BMT in primary DMVO.

Methods We systematically searched PubMed, Cochrane Library and Embase, from inception to August 14, 2022, for studies comparing EVT with BMT in DMVO-AIS. We adopted the Distal Thrombectomy Summit Group’s definition of DMVO. Efficacy outcomes were functional independence (90-day modified Rankin Scale (mRS) 0–2) and excellent functional outcomes (90-day mRS 0–1). Safety outcomes were symptomatic intracranial hemorrhage (sICH) and 90-day mortality.

Results Fourteen observational and two randomized-controlled studies were included, with 1202 patients receiving EVT and 1267 receiving BMT. After trim-and-fill correction, EVT achieved significantly better odds of functional independence than BMT (adjusted OR 1.61, 95% CI 1.06 to 2.43). There were no significant differences in overall excellent functional outcomes (OR 1.23, 95% CI 0.88 to 1.71), sICH (OR 1.44, 95% CI 0.78 to 2.66), and mortality (OR 1.03, 95% CI 0.73 to 1.45). Stratified by EVT method, mechanical thrombectomy±intra-arterial thrombolysis achieved more excellent functional outcomes than BMT (OR 1.59, 95% CI 1.13 to 2.23). In mild strokes (National Institutes of Health Stroke Scale score <6), EVT caused significantly more sICH (OR 6.30, 95% CI 1.55 to 25.64).

Conclusions EVT shows promising efficacy benefit over BMT for primary DMVO-AIS. Further randomized controlled trials are necessary to evaluate the efficacy and safety of EVT in DMVO-AIS.

  • Thrombectomy
  • Thrombolysis
  • Stroke

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.

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Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.

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  • BYT and LLY are joint senior authors.

  • Contributors EDWL, KZXT and GYRK were responsible for the literature search, risk of bias assessment, data extraction and drafting of the manuscript. BYQT and LLLY contributed equally to the conception, design and supervision of the study. All authors contributed to analysis and interpretation of data, critical revision of the manuscript for intellectual content, and have read and approved the final submitted manuscript. LLLY is responsible for the overall content as guarantor.

  • Funding BYQT was supported by the MOH Healthcare Research Scholarship, National Medical Research Council, Singapore. LLLY was supported by the National Medical Research Council, Singapore (NMRC/MOH-TA91Nov-0003).

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; internally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.