Malignant emboli on transcranial Doppler during carotid stenting predict postprocedure diffusion-weighted imaging
Mohammed A Almekhlafi1, Andrew M Demchuk, Sachin Mishra
1Departments of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
Stroke
|March 28, 2013
Summary
Carotid angioplasty and stenting (CAS) procedures generate many embolic signals, particularly during device deployment. Malignant macroemboli detected by transcranial Doppler predict new diffusion-weighted imaging lesions, highlighting risks during CAS.
Area of Science:
- Neuroscience
- Interventional Cardiology
- Medical Imaging
Background:
- Carotid angioplasty and stenting (CAS) carries a higher risk of periprocedural stroke than endarterectomy.
- Identifying specific CAS steps associated with embolization is crucial for improving safety.
- Procedural safety of CAS needs further evaluation to mitigate neurological complications.
Purpose of the Study:
- To evaluate the safety of CAS by correlating procedural transcranial Doppler (TCD) findings with postprocedure diffusion-weighted imaging (DWI) lesions.
- To identify CAS procedural steps with the highest likelihood of embolization.
- To assess the predictive value of embolic signals on TCD for new DWI lesions.
Main Methods:
- Prospective study involving 30 subjects undergoing CAS.
- Transcranial Doppler monitoring during 11 distinct CAS procedural steps.
- Classification of embolic signals as microemboli (≤1) or malignant macroemboli (>1).
- Post-CAS MRI to detect diffusion-weighted imaging (DWI) lesions.
- Negative binomial regression analysis to correlate TCD emboli with DWI lesions.
Main Results:
- A high median embolic signal count (212.5) was observed, with stent deployment (58) and protection device deployment (30) showing the highest counts.
- 80% of subjects (24/30) developed new DWI lesions on post-CAS MRI.
- Each malignant embolus increased the expected count of DWI lesions by 1% (P=0.032).
- Only 6.7% of subjects experienced new or worsening clinical deficits.
Conclusions:
- Carotid angioplasty and stenting procedures generate a significant number of embolic signals, especially during device deployment.
- The majority of patients undergoing CAS develop new DWI lesions, but clinical deficits are infrequent.
- Malignant macroemboli identified during CAS are predictive of new DWI lesions, underscoring their clinical significance.
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