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Published on: July 9, 2020
Filter-protected versus unprotected carotid artery stenting: a randomised trial
Sumaira Macdonald1, David H Evans, Paul D Griffiths
1Vascular Radiology, Freeman Hospital, Newcastle upon Tyne, UK. Sumaira.macdonald@nuth.nhs.uk
Insights
Filter protection during carotid artery stenting (CAS) did not reduce brain embolisation. In fact, filter-protected CAS showed more new brain lesions on DWI and higher microembolisation rates on TCD compared to unprotected CAS.
Area of Science:
- Neurology
- Vascular Surgery
- Medical Imaging
Background:
- Carotid artery stenting (CAS) is a procedure to treat symptomatic carotid artery stenosis.
- Embolisation to the brain is a potential complication during CAS.
Purpose of the Study:
- To investigate whether using a filter during CAS reduces embolisation to the brain.
- To compare brain lesion incidence and microembolisation rates between filter-protected and unprotected CAS.
Main Methods:
- Thirty patients with >70% symptomatic carotid artery stenosis were randomized to filter-protected or unprotected CAS.
- Diffusion-weighted magnetic resonance imaging (DWI) assessed new brain lesions before and after CAS.
- Transcranial Doppler (TCD) monitored high-intensity transient signals (emboli) during the procedure.
Main Results:
- No significant differences in patient demographics or presenting symptoms between groups.
- Filter-protected CAS showed a trend towards more new DWI lesions at 1-3 hours (29% vs 18%) and 30 days (26% vs 12%).
- Significantly higher total and particulate emboli counts were observed on TCD during filter-protected CAS (p=0.01 and p=0.03).
Conclusions:
- Filter-protected CAS is associated with increased new brain lesions on DWI and higher microembolisation rates on TCD.
- The clinical significance of these findings warrants further investigation.
- Current evidence suggests filter protection may not reduce, and could potentially increase, embolic events during CAS.
Background:
Our aim was to determine whether filter protection reduces embolisation to the brain during carotid artery stenting (CAS).
Methods:
Thirty patients with symptomatic carotid artery stenosis > or =70% (North American Symptomatic Carotid Endarterectomy Trial) were randomly assigned to filter-protected or unprotected CAS. Diffusion-weighted magnetic resonance imaging (DWI) of the brain was performed before and at 3 time points after CAS. In a subset of patients, high-intensity transient signals on transcranial Doppler (TCD) were recorded with categorisation of emboli. Data were independently reviewed off-site.
Results:
There were no significant differences in mean age, proportion of octogenarians or presenting symptoms between the groups. On procedural DWI (1-3 and 24 h after stenting), there were 7/24 (29%) and 4/22 (18%) new lesions in protected and unprotected patients respectively (p = 0.38). At 30 days there were 9/33 (26%) and 4/33 (12%) lesions in protected and unprotected patients, respectively (p = 0.1). On TCD there were significantly more signals in total as well as particulate emboli during filter-protected CAS (426.5 and 251.3) than during unprotected CAS (165.2 and 92) - p = 0.01 and 0.03, respectively.
Conclusions:
Filter-protected CAS is associated with an increase in new lesions on DWI and significantly higher rates of total and particulate microembolisation on TCD than unprotected CAS. The clinical significance of these findings requires further study.