Flow impairment during protected carotid artery stenting: impact of filter device design
Marco Roffi1, Matthias Greutmann, Urs Schwarz
1Andreas Gruntzig Cardiovascular Catheterization Laboratories, Department of Cardiology, University Hospital, Raemistrasse 100, Zurich, Switzerland. marco.roffi@usz.ch
Insights
Filter design significantly impacts blood flow during carotid artery stenting (CAS). Angioguard filters caused more flow impairment in the internal carotid artery (ICA) compared to other devices, highlighting the importance of device selection in CAS procedures.
Area of Science:
- Interventional Cardiology
- Vascular Surgery
- Medical Device Engineering
Background:
- Carotid artery stenting (CAS) is a procedure to open blocked carotid arteries.
- Emboli protection devices (EPDs) are used during CAS to prevent stroke.
- Filter-type EPDs are one type of device used for emboli protection.
Purpose of the Study:
- To evaluate how different filter designs affect blood flow in the internal carotid artery (ICA) during CAS.
- To identify if specific filter types are associated with increased risk of blood flow impairment.
Main Methods:
- A retrospective review of 115 filter-protected CAS procedures in 107 patients.
- Analysis of data from procedures using Angioguard, FilterWire EZ, and Spider filters.
- Correlation of filter type with observed blood flow impairment in the ICA.
Main Results:
- Blood flow impairment occurred in 22% of procedures, primarily due to filter obstruction.
- Angioguard filters were associated with significantly higher rates of flow impairment (32.3%) compared to FilterWire EZ (6.2%) and Spider (6.7%).
- Complete flow cessation occurred only with Angioguard filters (19%).
Conclusions:
- Blood flow impairment in the ICA during filter-based CAS is a notable complication.
- The type of filter used is a critical factor influencing the occurrence of flow impairment.
- Device selection is crucial for optimizing safety and efficacy in CAS procedures.
Purpose:
To investigate the impact of filter design on blood flow impairment in the internal carotid artery (ICA) among patients undergoing carotid artery stenting (CAS) using filter-type emboli protection devices (EPD).
Methods:
Between July 2003 and March 2007, 115 filter-protected CAS procedures were performed at an academic institution in 107 consecutive patients (78 men; mean age 68 years, range 38-87). The Angioguard, FilterWire EZ, and Spider filters were used in 68 (59%), 32 (28%), and 15 (13%) of cases, respectively. Patient characteristics, procedural and angiographic data, and outcomes were prospectively entered into an electronic database and reviewed retrospectively along with all angiograms.
Results:
Flow impairment while the filter was in place was observed in 25 (22%) cases. The presumptive reason of flow impairment was filter obstruction in 21 (18%) instances and flow-limiting spasm at the level of the filter in 4 (4%). In all cases, flow was restored after retrieval of the filter. Flow obstruction in the ICA occurred more frequently with Angioguard (22/68; 32.3%) than with FilterWire EZ (2/32; 6.2%) or Spider (1/15; 6.7%; p = 0.004). No flow occurred in 13 (19%) procedures, all of them protected with Angioguard; no patient treated with other devices experienced this event (p = 0.007). Two (8.0%) strokes occurred in procedures associated with flow impairment, while 1 (1.1%) event was observed in the presence of preserved flow throughout the intervention (p = 0.11).
Conclusion:
Flow impairment in the ICA during filter-based CAS is common and related to the type of filter used.