Conformity of carotid stents with vascular anatomy: evaluation in carotid models.
OBJECTIVE
Conformity between self-expanding Wallstents and vascular anatomy is limited. Because of a lack of longitudinal flexibility, straightening effects on vascular curves occur and may result in stent-induced kinking. Our purpose was to evaluate the conformity of self-expanding stents with the course and endoluminal surface of silicone models of the normal human carotid artery.


METHODS
Five different types of self-expanding carotid stents were implanted into simplified pulsatile perfused silicone models of the carotid bifurcation. The models embody elastic properties of the vessel wall similar to those of normal human arteries. All stents had the same nominal diameter and length and bridged the external carotid artery origin as well as a consecutive curve at the initial segment of the internal carotid artery. Conventional radiographs of the model were compared before and after stent placement to record changes of shape and course of the silicone artery. Dehiscences between stent filaments and arterial wall were measured on digital subtraction angiograms of the model.


RESULTS
Implantation of braided Wallstents or the Expander with continuous filaments induced considerable straightening effects on the bifurcation angle, as well as on the curves of the internal carotid artery. Segmented designs of modular nitinol stents complied better with vascular tortuosity and showed improved adaption between stent and the endoluminal surface of the model.


CONCLUSIONS
Model experiments show that segmented nitinol stents improve the conformity between the prosthesis and vascular anatomy, and confirm new carotid stent concepts as an alternative to the Wallstent.
Tanaka
Norimitsu
N
Department of Radiology, Kurume University School of Medicine, Kurume, Japan.
Martin
Jean-Baptiste
JB
Tokunaga
Koji
K
Abe
Toshi
T
Uchiyama
Yusuke
Y
Hayabuchi
Naofumi
N
Berkefeld
Joachim
J
Rüfenacht
Daniel A
DA
D000497:Alloys; D000800:Angioplasty, Balloon / Q000295:instrumentation*; D002342:Carotid Artery, External / Q000033:anatomy & histology*; D002343:Carotid Artery, Internal / Q000033:anatomy & histology*; D016893:Carotid Stenosis / Q000628:therapy*; D002858:Chromium Alloys; D003187:Compliance; D019544:Equipment Failure Analysis; D006801:Humans; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D015607:Stents / Q000592:standards*
D000497:Alloys; D002858:Chromium Alloys; C013616:nitinol