Effect of different expansion strategies on coronary stent deployment in a tapered artery

Abstract

Abstract. BACKGROUND: Vascular stenting has been widely used to treat vessel stenosis. However, long-term successes of the procedure are often compromised by late stent thrombosis (ST) and in-stent restenosis (ISR), especially in tapered arteries. OBJECTIVE: The aim of this study was to choose a reasonable expansion strategy for tapered arteries. METHODS: A balloonexpandable coronary stent deployment in a tapered vessel was numerically studied fol-lowing three strategies: (i) selecting the proximal diameter of the tapered vessel as the reference diameter to expand the stent, (ii) selecting the middle diameter of the tapered vessel as the reference diameter to expand the stent, and (iii) selecting the distal diameter of the tapered vessel as the reference diameter to expand the stent. RESULTS: Computational results showed that the first expansion strategy resulted in the maximum vessel stress and the best stent apposition, while the third strategy resulted in the minimal vessel stress and the worst stent appo-sition. Meanwhile, the second expansion strategy achieved a trade-off between the first and third strategies, leading to acceptable vessel stress and stent apposition. CONCLUSIONS: The second expansion strategy is the most reasonable choice for tapered vessels, and it should be considered when implanting a stent.

A Systematic Review on Cardiovascular Stent and Stenting Failure: Coherent Taxonomy, Performance Measures, Motivations, Open Challenges and Recommendations

“…In 2017, Shanahan et al [62] studied the evaluation of the time-dependent viscoelastic response for a braided stent undergo to crimp via in-vitro and numerical simulation by using ABAQUS software. Moreover, many studies sough into many topics that will related to stent design such as, the developing of stent resistant through estimate the effect of various textile parameters on the fatigue effectiveness [6], [63] and balloon expendable coronary stent widening inside a tapered vessel [64].…”

“…Second, performance of stent designs; this portion centered on these studies are evaluated based on stent design performance which are discussed here. However, to further information for the application of curvature fatigue in stentgraft as well as connection their design and bending strength [64]. Moreover, by using such delicate reconstructions of in-vitro (polytetrafluoroethylene tube, PTFE) and ex-vivo (canine artery) deployed self-expanding intracranial stents could be analyzing blood flow through a stented ''vessel'' [65].…”

“…Under the complicated stress conditions that which experienced physiologically (daily body activities, blood pressure and various cyclic motions) could be short of accuracy to evaluate the fatigue durability of stent graft when compared with the cyclic fatigue in bending, as well as, the data from fatigue analysis allow to search several thoughts on stent lifetime [44], [47], [54], [64], [72], [78], [88]. However, the use of polymer or metallic based on bioabsorbable stents is possible solution to reduce these problems, that head for to be degraded by corrosion and completely eliminated [67], [79].…”

“…Even the design of a stent is a relatively mature subject, fatigue failure has recently appeared one of main disadvantages while accurately the limited information about the relationship between fatigue and degradation, as well as, the wide variations from patient specific aortic arteries in terms of shape, material properties, size, and leading conditions that impacted with mechanical properties [12], [42], [64], [72], [78]. Arising number of cyclic loads on stent device after implantation has been often connected with fatigue issues [45].…”

“…The previous topics of this survey were examined many subjects that related to the main stent design performance, however, the authors recommendations in their research papers kind of future work most taken into account such as, there are few research papers focused on the bending performance of fully covered biodegradable polydioxanone biliary stent which simulated via finite element method and still numerical mimic bending topic lack to accurately [10], also, may the results be inspired to develop of stent-graft fatigue evaluation and new prospects of deformation mechanisms [18], [64]. Yet, the results which come out of deformation modes in this paper may help to guide the optimization of new stents which improved the mechanical performance [13].…”