An in vitro analysis of a carotid artery stent with a protective porous membrane.
OBJECTIVE
To prove the effectiveness of a new stent concept with integrated protection (MembraX [MX]) by comparing it with five cerebral protection devices designed for carotid angioplasty in an in vitro model.


METHODS
Two simulation series of embolization from carotid angioplasty have been performed. In the first series, polyvinyl-alcohol particles (150-250 microm [small], 355-500 microm [medium], 710-1000 microm [large]; 5 mg each) were injected into a silicone flow model simulating the aortic arch with a carotid bifurcation. The particles were injected proximally to the partially deployed MX stent or one of the following protection devices: Angioguard (AG), FilterWire EX (EX), Trap, Neuroshield (NS), or GuardWire Plus (GW). Particles evading the protection device were caught in a filter at the end of the flow model and weighed. In the second series, human plaque material (8-12 particles; total weight 6.09 +/- 0.01 mg; 500-1500 microm) was injected into the model with the respective devices. MX was compared with the AG, EX, Trap, and NS devices.


RESULTS
MX had the most effective overall filtration performance for polyvinyl alcohol particles in the effluent of the internal carotid artery (ICA; 0.43 mg, 2.9%), compared with NS (0.53 mg, 3.5%), GW (1.10 mg, 7.0%), EX and AG (1.18 and 1.21 mg, respectively; 7.8% and 8.0%), and Trap (1.24 mg, 8.2%). MX performed best for the small particles (2.0% passed particles into ICA; P < .05 compared with all). Human plaque material was retained best in the in vitro model by MX (0.0%), followed by NS (0.8%), EX (1.3%), Trap (2.6%), and AG (4.4%).


CONCLUSIONS
In vitro, none of the tested devices had the ability to prevent embolization completely. Comparing current designs, the MX device captured the highest percentage of the three different particle groups. Tested with human plaque emboli, MX performed effectively in filtering the particles in the ICA.
Müller-Hülsbeck
Stefan
S
Department of Radiology, University Hospital, Arnold-Heller-Strasse 9, 24105 Kiel, Germany. muehue@rad.uni-kiel.de
Hüsler
Erhard J
EJ
Schaffner
Silvio R
SR
Jahnke
Thomas
T
Glass
Christoph
C
Wenke
Rüdiger
R
Heller
Martin
M
D000704:Analysis of Variance; D000800:Angioplasty, Balloon / Q000379:methods; D001013:Aorta, Thoracic / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000503:physiopathology / Q000601:surgery*; D016893:Carotid Stenosis / Q000517:prevention & control; D020099:Coated Materials, Biocompatible; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D066298:In Vitro Techniques; D020766:Intracranial Embolism / Q000517:prevention & control; D008566:Membranes; D008953:Models, Anatomic; D008954:Models, Biological; D011142:Polyvinyl Alcohol / Q000008:administration & dosage; D011482:Protective Devices; D015607:Stents
D020099:Coated Materials, Biocompatible; D011142:Polyvinyl Alcohol