Comparison of carotid stents: an in-vitro experiment focusing on stent design.
ABSTRACT To examine and compare different carotid stent designs with regard to flexibility, adaptability (adjustability), conformability (compliance) to the vessel, and scaffolding to reduce plaque prolapse and embolization.
Six stents of different design were compared (Precise, Acculink, Protégé, Xact, Wallstent, and Cristallo Ideale). Optical microscopy was used to determine exact dimensions and scaffolding of each stent. Radial force was tested using a parallel plate setup, and flexibility (torsion and bending) was measured in water at body temperature. Particle penetration simulation was performed using plastic spheres from 1.5- to 6.0-mm outer diameter.
Stent dimensions met the manufacturers' data; none of the products showed any failure during the test program. Cell sizes in the middle part of the stents ranged from 1.36 mm(2) (Wallstent) to 15.10 mm(2) (Acculink). Bending forces at 20 degrees /30 degrees ranged from 0.063 N / 0.074 N (Cristallo Ideale) to 0.890 N / 0.616 N (Xact); forces to achieve torsion at 10 degrees /15 degrees ranged from 0.032 N / 0.043 N (Acculink) to 0.905 N / 1.071 N (Xact). According to the parallel plate method, mean lowest force was measured for Xact (0.765 N), while the Wallstent had the highest force (2.136 N). Mean radial force measurements were lowest for Cristallo Ideale (9.06 N at mid part) and highest for Protégé (24.09 N). The Cristallo Ideale stent at mid part resisted penetration by all but the smallest plastic spheres (1.5-mm spheres penetrated only at 0.65 N); the Precise and Protégé stent had the highest variation in sphere penetration (1.5- to 4.0-mm spheres). Only the Acculink let 6-mm spheres penetrate.
Despite comparable stent sizes, these carotid stents showed differences in behavior due to stent design. The open-cell design displayed the greatest flexibility and adaptability to the vessel but easily allowed particle penetration due to the open structure. Closed-cell designs had low flexibility and thus low adaptability to the vessel but high resistance to particle penetration due to the closed-cell design and high scaffolding. The hybrid stent design (Cristallo Ideale) was able to combine both the flexibility of an open-cell structure and the resistance to particle penetration of closed-cell structures.
- SourceAvailable from: Francesco Iannaccone[Show abstract] [Hide abstract]
ABSTRACT: Stroke is a heterogeneous disease caused by a sustained interruption of the blood supply to part of the brain. Prevention and treatment of this disease is of primary importance as it has been estimated to be the second leading cause of death worldwide. Due to the large number of possible origins there is no general strategy for preventive treatment and evidence based recommendations are given. However major causes of stroke can be confined to few vascular districts. More and more evidence is supporting the hypothesis that biomechanical and hemodynamic parameters can be related to catastrophic cerebrovascular events. In this context structural and fluidodynamic computer simulations offer an optimal tool to quantify these predictors. On the other hand the advances in medical imaging allow providing realistic in vivo conditions (such as reliable anatomical geometries and initial mechanical state) for patient specific analysis. This paper reviews the progress and the state of art of numerical simulation used to analyze the early stages and the progression of the disease as well as their potential as tool for risk assessment, for treatment outcome and procedure planning.Cardiovascular Engineering and Technology. 12/2013;
- [Show abstract] [Hide abstract]
ABSTRACT: Purpose : To report the initial clinical experience with a new hybrid stent to prevent neurological events during carotid artery stenting. Case Report : A 77-year-old asymptomatic man presented with de novo high-grade stenosis (80%) of the right internal carotid artery (ICA) and occlusion of the contralateral ICA. He was referred for right ICA stenting with a 6/8-mm×40-mm Gore Carotid Stent under cerebral protection using the Gore Carotid Filter. The stent delivery system tracked well over the filter wire and deployment was precise. The result was satisfactory, with 10% residual stenosis. No neurological events occurred during 6 months of follow-up. Conclusion : Initial clinical experience with this new carotid hybrid stent showed satisfactory results, including ease of use, precise deployment, conformability to the wall, and protection against embolization.Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists. 08/2014; 21(4):601-604.
- [Show abstract] [Hide abstract]
ABSTRACT: Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP.Neuroradiology 08/2014; · 2.70 Impact Factor