Conformity of Carotid Stents with Vascular Anatomy: Evaluation in Carotid Models
Norimitsu Tanakaa,
Jean-Baptiste Martinb,
Koji Tokunagab,
Toshi Abea,
Yusuke Uchiyamaa,
Naofumi Hayabuchia,
Joachim Berkefeldc and
Daniel A. Rüfenachta
a Department of Radiology, Kurume University School of Medicine, Kurume, Japan
b Section of Neuroradiology, Department of Radiology, University Hospital of Geneva, Switzerland
c Institute of Neuroradiology, University Hospital of Frankfurt, Germany
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FIG 1. Simplified silicone model of the human carotid artery bifurcation with a nominal angulation between the CCA and initial ICA segment of 30° counterbalanced by a curve.
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FIG 2. Digital images of the model after implantation of a self-expanding carotid stent covering the ICA curve and the bifurcation as a basis for the measurement of parameters for quantification of stent conformity.
A and B, The dehiscence factor is calculated by dividing the areas of dehiscence (highlighted in B) by the area covered by the stent.
C, Measurement of the ICA offset as the maximal deviation of ICA tortuosity perpendicular to the CCA midaxis (upper arrows). Definition of the CCA-ICA angle as the angulation (asterisk) between the CCA midaxis and the midaxis of the initial ICA segment up to a level of 1.5 cm above a bifurcational 0-level is indicated by a line through the midpoint of the external carotid artery origin.
D, Measurement of the ICA angle (asterisk) between the tangents through the midaxes of both limbs of the ICA curve.
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FIG 3. Digital radiographs of the model without stent and after implantation of five types of self-expanding carotid stents. Note the differences of stent conformity between stents braided from continuous filaments (Wallstent and Expander) and segmented nitinol stents with an open cell design (Jostent, SMART and Zilver). See text for further explanations.
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