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2643088 
Journal Article 
A Comparative Analysis of Bench-Top Performance Assessment of Distal Protection Filters in Transient Flow Conditions 
Siewiorek, GM; Wholey, MH; Finol, EA 
2012 
Yes 
Journal of Endovascular Therapy
ISSN: 1526-6028
EISSN: 1545-1550 
19 
2 
249-260 
22545892 
WOS:000303644300019 
Purpose: To compare the performance in vitro of 6 distal protection filters (DPFs) on the basis of filtration ability and effects on pressure gradient and vascular impedance in a flow model of the internal carotid artery (ICA).



Methods: Six DPFs (Accunet, Angioguard, Filter Wire, Gore Embolic Filter, NAV6, and SpiderFX) were evaluated in a physiologically realistic flow loop. A blood analog was heated to body temperature and circulated by a pulsatile pump outputting a time-varying flow rate representative of the ICA. The ICA flow model was a highly curved tube representing a challenging site for filter deployment. The DPFs were deployed at the apex of the curved segment, and 2 sizes of microspheres (143 and 200 pm) were injected to simulate embolization. The capture efficiency, pressure gradient, normalized pressure gradient, and vascular impedance were calculated.



Results:The Gore filter had high capture efficiency (143 mu m: 99.97%; 200 mu m: 100.00%) with relatively small increases in pressure gradient (143 mu m: +27%; 200 mu m: +20%) and vascular impedance (143 mu m: +23.4%; 200 mu m: +6.1%) after particles were injected. Spider had the lowest capture efficiency (143 mu m: 1.50%; 200 mu m: 19.34%, p<0.0005), while NAV6 (143 mu m: +916%, p<0.0005) and Accunet (200 mu m: +179%, p<0.0005) yielded the largest pressure gradient increases.



Conclusion: A bench-top flow apparatus exhibiting physiologically realistic conditions was developed by combining pulsatile flow and a body temperature blood analog. Using microspheres larger than the pore size of most of the DPFs, the device-wall apposition has an important effect on the overall filter performance and the global fluid dynamics in the flow model. J Endovasc Ther. 2012;79:249-260 
in vitro experiment; flow model; internal carotid artery; stent; embolic protection filter; distal protection; vascular impedance; pulsatile flow