Mechanical thrombectomy for acute ischemic stroke with cerebral microbleeds

Area of Science:

• Neurology
• Radiology
• Cardiovascular Research

Background:

• Cerebral microbleeds (CMBs) influence on post-thrombolytic hemorrhagic transformation (HT) in acute ischemic stroke is debated.
• Assessing CMBs' impact is crucial for guiding stroke treatment decisions.

Purpose of the Study:

• To determine the association between CMBs and HT in patients with large-vessel occlusion stroke undergoing mechanical thrombectomy.
• To evaluate the relationship of CMBs with clinical outcomes, including mortality and functional status.

Main Methods:

• Retrospective analysis of 206 acute stroke patients treated with mechanical thrombectomy devices (Merci, Penumbra, stent-retriever).
• CMBs identified on pretreatment T2-weighted, gradient-recall echo MRI.
• Statistical analysis of CMB presence, burden, and distribution against HT, complications, mortality, and clinical outcomes.

Main Results:

• CMBs were present in 18.0% of patients (37/206), with a low burden (14 patients with ≥2 CMBs, 1 with ≥5 CMBs).
• No significant differences in HT rates (37.8% vs 45.6%), parenchymal hematoma, procedural complications, or in-hospital mortality were observed between patients with and without CMBs.
• CMBs were not independently associated with HT or mortality in patients treated with thrombectomy or combined thrombolysis/thrombectomy.

Conclusions:

• Cerebral microbleeds do not elevate the risk of hemorrhagic transformation or mortality after mechanical thrombectomy for acute stroke.
• Excluding patients with CMBs from mechanical thrombectomy is not justified based on current findings.
• Further research is needed to clarify the risk of HT in patients with a high burden of CMBs (≥5).