Related Experiment Video
Updated: Mar 29, 2026
Microvascular Embolism Mouse Model for In Vivo Two-photon Microscopy Using Fluorescent Polystyrene Microspheres
Published on: November 21, 2025
New Cerebral Microbleeds After Mechanical Thrombectomy for Large-Vessel Occlusion Strokes
Zhong-Song Shi1, Gary R Duckwiler, Reza Jahan
1From the Department of Neurosurgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (Z-SS); Division of Interventional Neuroradiology (GRD, RJ, ST, NRG, VS, FV), Department of Neurology (JLS, DK, LKA, SS, DSL), Department of Emergency Medicine (SS), Department of Neurosurgery (NRG, PMV), Division of Diagnostic Neuroradiology (NS, JPV), and Neurovascular Imaging Research Core (DSL), David Geffen School of Medicine at UCLA, Los Angeles, CA; Department of Radiology, Kaiser Permanente Medical Center, Los Angeles, CA (LF); Interventional Neuroradiology and Neurocritical Care Services, Madigan Army Medical Center, Tacoma, WA (YL), Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-sen University, Guangzhou, China (Z-SS).
Abstract:
The interval appearance of cerebral microbleeds (CMBs) after endovascular treatment has never been described. We investigated the frequency and predictors of new CMBs that developed shortly after mechanical thrombectomy for acute ischemic stroke, and its impact on clinical outcome.We retrospectively analyzed patients with large-vessel occlusion strokes treated with Merci Retriever, Penumbra System, or stent-retriever devices. Serial T2*-weighted gradient-recall echo (GRE) magnetic resonance imaging (MRI) before and 48 h after endovascular thrombectomy were assessed to identify new CMBs. We examined independent factors associated with new CMBs after mechanical thrombectomy. We analyzed the association of the presence, burden, and distribution of new CMBs with clinical outcome.A total of 187 consecutive patients with serial GRE were enrolled in this study. CMBs were evident in 36 (19.3%) patients before mechanical thrombectomy. New CMBs occurred in 41 (21.9%) patients after mechanical thrombectomy. Of the 68 new CMBs, 45 appeared in the lobar location, 18 in the deep location and 5 in the infratentorial location. The presence of baseline CMBs was associated with new CMBs after mechanical thrombectomy (OR 5.38; 95% CI 2.13-13.59; P < 0.001), no matter whether the patients were treated primarily with mechanical thrombectomy or with intravenous thrombolysis followed by mechanical thrombectomy. Patients with new CMBs did not have increased rates of hemorrhagic transformation, in-hospital mortality, and modified Rankin Scale score 4 to 6 at discharge.New CMBs are common after mechanical thrombectomy in one-fifth of patients with acute ischemic stroke. Baseline CMBs before mechanical thrombectomy predicts the development of new CMBs. New CMBs after mechanical thrombectomy do not influence clinical outcome.
Insights
New cerebral microbleeds (CMBs) are common after mechanical thrombectomy for acute ischemic stroke, occurring in nearly one-fifth of patients. Pre-existing CMBs predict their development, but new CMBs do not impact clinical outcomes.
Area of Science:
- Neurology
- Neuroradiology
- Interventional Neurology
Background:
- Cerebral microbleeds (CMBs) are associated with cerebrovascular diseases.
- The appearance of new CMBs after endovascular treatment for acute ischemic stroke remains undescribed.
- Understanding CMBs post-thrombectomy is crucial for assessing treatment safety and outcomes.
Purpose of the Study:
- To investigate the frequency and predictors of new cerebral microbleeds (CMBs) after mechanical thrombectomy.
- To determine the impact of new CMBs on clinical outcomes, including hemorrhagic transformation and mortality.
Main Methods:
- Retrospective analysis of 187 patients with large-vessel occlusion stroke treated with mechanical thrombectomy.
- Serial T2*-weighted gradient-recall echo (GRE) MRI scans were performed before and 48 hours after treatment.
- Statistical analysis identified factors associated with new CMBs and their correlation with clinical outcomes.
Main Results:
- New CMBs were observed in 41 (21.9%) patients post-mechanical thrombectomy.
- The presence of baseline CMBs significantly predicted the development of new CMBs (OR 5.38).
- New CMBs did not correlate with increased hemorrhagic transformation, in-hospital mortality, or poor functional outcome at discharge.
Conclusions:
- New cerebral microbleeds are a frequent finding after mechanical thrombectomy for acute ischemic stroke.
- Baseline CMBs are a key predictor for the development of new CMBs post-treatment.
- The occurrence of new CMBs does not appear to negatively influence short-term clinical outcomes.
