Second generation drug eluting stents(DES) have shown better safety and efficacy in comparison to first generation DES,because of thinner struts,nondurable polymers and coating with better anti-proliferative drugs.The...Second generation drug eluting stents(DES) have shown better safety and efficacy in comparison to first generation DES,because of thinner struts,nondurable polymers and coating with better anti-proliferative drugs.The newer DES with cobalt alloy base have demonstrated a greater trackability,deliverability,conformability,flexibility and radio-opacity.However,these thin strut stents have a downside of poor longitudinal axial strength,and therefore get easily deformed/ compressed at their end with a slight trauma during exchange of various catheters.We hereby report two cases of "longitudinal stent compression(LSC)" of everolimus-eluting stent,which happened during percutaneous coronary intervention of right coronary artery.Both the cases were successfully managed with non-compliant balloon dilatation.Various reasons for LSC and its management are discussed in the article.展开更多
Several recent reports have described the occurrence of longitudinal stent deformation(LSD, defined as the distortion or shortening of a stent along the longitudinal axis), following its successful deployment. However...Several recent reports have described the occurrence of longitudinal stent deformation(LSD, defined as the distortion or shortening of a stent along the longitudinal axis), following its successful deployment. However, few reports have described LSD prior to any stent deployment. This previously unrecognized complication is the result of modifications to stent design. It has been noted that the new-generation stent platforms have a reduced number of connectors, which in turn causes a reduction in longitudinal stent strength. To corroborate previous findings by our lab and others(Vijayvergiya et al, 2013), we describe here two cases of LSD prior to stent deployment that occurred due to crushing of the proximal stent edge by the guide catheter while attempting to withdraw the crimped stent. In addition, we discuss the associated risk factors, such as the length of the stent, and specific management strategies, including technical guidelines and use of fluoroscopic guidance for maneuvering the stent during the procedure.展开更多
Excellent mechanical property of the anti-compression or high collapse pressure has become an essential feature of new coronary stents. How to determine the design parameters of stent becomes the key to improve the st...Excellent mechanical property of the anti-compression or high collapse pressure has become an essential feature of new coronary stents. How to determine the design parameters of stent becomes the key to improve the stent quality. An integrated approach using radial basis function neural network （RBFNN） and genetic algorithm （GA） for the optimization of anti-compression mechanical property of stent is presented in this paper. First, finite element simulation and RBFNN are used to map the complex non-linear relationship between the collapse pressure and stent design parameters. Then GA is employed with the fitness function based on an RBFNN model for arriving at optimum configuration of the stent by maximizing the collapse pressure. The results of numerical experiment demonstrate that the combination of RBFNN and GA is an effective approach for the mechanical properties optimization of stent.展开更多
文摘Second generation drug eluting stents(DES) have shown better safety and efficacy in comparison to first generation DES,because of thinner struts,nondurable polymers and coating with better anti-proliferative drugs.The newer DES with cobalt alloy base have demonstrated a greater trackability,deliverability,conformability,flexibility and radio-opacity.However,these thin strut stents have a downside of poor longitudinal axial strength,and therefore get easily deformed/ compressed at their end with a slight trauma during exchange of various catheters.We hereby report two cases of "longitudinal stent compression(LSC)" of everolimus-eluting stent,which happened during percutaneous coronary intervention of right coronary artery.Both the cases were successfully managed with non-compliant balloon dilatation.Various reasons for LSC and its management are discussed in the article.
文摘Several recent reports have described the occurrence of longitudinal stent deformation(LSD, defined as the distortion or shortening of a stent along the longitudinal axis), following its successful deployment. However, few reports have described LSD prior to any stent deployment. This previously unrecognized complication is the result of modifications to stent design. It has been noted that the new-generation stent platforms have a reduced number of connectors, which in turn causes a reduction in longitudinal stent strength. To corroborate previous findings by our lab and others(Vijayvergiya et al, 2013), we describe here two cases of LSD prior to stent deployment that occurred due to crushing of the proximal stent edge by the guide catheter while attempting to withdraw the crimped stent. In addition, we discuss the associated risk factors, such as the length of the stent, and specific management strategies, including technical guidelines and use of fluoroscopic guidance for maneuvering the stent during the procedure.
基金supported by National Basic Research Program of China (973 program,No.2006CB708610)Jiangsu Provincial Key Natural Science Foundation of China (No.BK2006709)Doctoral Foundation of Ministry of Education of China (No.20060286012).
文摘Excellent mechanical property of the anti-compression or high collapse pressure has become an essential feature of new coronary stents. How to determine the design parameters of stent becomes the key to improve the stent quality. An integrated approach using radial basis function neural network （RBFNN） and genetic algorithm （GA） for the optimization of anti-compression mechanical property of stent is presented in this paper. First, finite element simulation and RBFNN are used to map the complex non-linear relationship between the collapse pressure and stent design parameters. Then GA is employed with the fitness function based on an RBFNN model for arriving at optimum configuration of the stent by maximizing the collapse pressure. The results of numerical experiment demonstrate that the combination of RBFNN and GA is an effective approach for the mechanical properties optimization of stent.
