Stent-grafts were commercialized rapidly and gained a broad clinical acceptance over the past two decades. However,relatively more recent recognition of particular stent-graft design shortcomings have been identified ...Stent-grafts were commercialized rapidly and gained a broad clinical acceptance over the past two decades. However,relatively more recent recognition of particular stent-graft design shortcomings have been identified which need to be addressed. It appears that various stent-graft designs may be more or less resistant to metal fatigue and /or fabric abrasions which can lead to type III and type IV endoleaks over the long term. Therefore,it is necessary to investigate the fatigue performance of the most common stentgraft designs: Z-stents and ringed stents,in a long-term in vitro fatigue simulation environment. This paper aimed to analyze nondestructively( gross observations) and destructively( fabric characteristics,mechanical and chemical properties) in order to put forward suggestions to improve the fabric and stent characteristics that may prevent type III and IV endoleaks. The fabric supported with ringed stent-grafts remained nearly completely intact after 168h. However, the fabric supported with Z-stents demonstrated significant damage. Fabric characteristics and tensile strength of the fibers did not present a significant difference between the control and fatigue simulated specimens. The crystallinity declined for both specimens. The fatigue performance of fabrics supported with ringed stents appears to be superior to that supported with Z-stents. The potential for a dynamic and destructive interaction between the apices of Z-stents which can lead to fraying and /or tearing of the graft fabric must be addressed in future designs.展开更多
The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of f...The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.展开更多
Recent developments in endovascular surgery （EVAR） have opened new avenues to successfully treat aneurysms with percutaneous deployment of stent-grafts. Manufacturers have preferred to use woven fabrics or microp...Recent developments in endovascular surgery （EVAR） have opened new avenues to successfully treat aneurysms with percutaneous deployment of stent-grafts. Manufacturers have preferred to use woven fabrics or microporous tubes which are supported by metallic frames or stents. Woven fabrics are much thinner than knits and this permits the use of a smaller delivery catheter. However, since woven constructions are stiffer and have little porosity, the tissue ingrowth is poor or absent. On the other hand, knitted constructions can be considered as a scaffold for tissue ingrowth, and hence they represent an attractive alternative because of their open structure and better conformability in the case of balloon deployment. The present study was undertaken to analyze the properties of two knitted and crimped polyester arterial prototype prostheses, one with and the other without a gelatin coating as sealant. Two commercial controls were also included in the study, namely the uncoated knitted polyester vascular prosthesis VP1200K, and its sealed version, the gelatin coated polyester knitted Gelsoft device, manufactured by Vascutek Ltd., Scotland, UK. In vitro testing consisted of analyzing the and marphology of the yam and fabric structures, and measuring the physical and mechanical properties of the grafts, including the water prow.ability, the longitudinal and radial campliance, and the suture retention strength. In order to the different properties of the four samples, tests were performed on the gelatin coated of sealed devices before and after gelatin removal. The results provided a useful comparison between the prototypes and the commercial contorl devices. The latter used ten times the amount of gelatin which had been applied as a coating in order to achieve the same low level of impemeability to water. The different amounts of gelatin also explained the different mechanical performance, such as compliance, for these prototype and control prostheses.展开更多
基金"111 Project"Biomedical Textile Materials Science and Technology of China(No.B07024)Fundamental Research Funds for the Central Universities of China(No.12D10112)+2 种基金National Students Innovation Plans of China(No.X120711287,No.12T1010601)National Natural Science Foundation of China(No.81371648)Research Fund for the Doctoral Program of Higher Education of China(No.20100075110001)
文摘Stent-grafts were commercialized rapidly and gained a broad clinical acceptance over the past two decades. However,relatively more recent recognition of particular stent-graft design shortcomings have been identified which need to be addressed. It appears that various stent-graft designs may be more or less resistant to metal fatigue and /or fabric abrasions which can lead to type III and type IV endoleaks over the long term. Therefore,it is necessary to investigate the fatigue performance of the most common stentgraft designs: Z-stents and ringed stents,in a long-term in vitro fatigue simulation environment. This paper aimed to analyze nondestructively( gross observations) and destructively( fabric characteristics,mechanical and chemical properties) in order to put forward suggestions to improve the fabric and stent characteristics that may prevent type III and IV endoleaks. The fabric supported with ringed stent-grafts remained nearly completely intact after 168h. However, the fabric supported with Z-stents demonstrated significant damage. Fabric characteristics and tensile strength of the fibers did not present a significant difference between the control and fatigue simulated specimens. The crystallinity declined for both specimens. The fatigue performance of fabrics supported with ringed stents appears to be superior to that supported with Z-stents. The potential for a dynamic and destructive interaction between the apices of Z-stents which can lead to fraying and /or tearing of the graft fabric must be addressed in future designs.
基金"111 Project" Biomedical Textile Material Science and Technology,China(No.B07024)National Natural Science Foundations of China(Nos.31100682,81371648)+2 种基金the Shanghai Construction of College Experiment Technique Team Project,China(No.101-07.0053014)the Fundamental Research Funds for the Central University,China(No.15D110126)the Department of Surgery at Laval University,Quebec and the Fonds de Recherche en Chirurgie Vasculaire of the CHU,Quebec,Canada
文摘The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.
基金111 Project"Biomedical Textile Materials Science and Technology"of China (No.B07024)
文摘Recent developments in endovascular surgery （EVAR） have opened new avenues to successfully treat aneurysms with percutaneous deployment of stent-grafts. Manufacturers have preferred to use woven fabrics or microporous tubes which are supported by metallic frames or stents. Woven fabrics are much thinner than knits and this permits the use of a smaller delivery catheter. However, since woven constructions are stiffer and have little porosity, the tissue ingrowth is poor or absent. On the other hand, knitted constructions can be considered as a scaffold for tissue ingrowth, and hence they represent an attractive alternative because of their open structure and better conformability in the case of balloon deployment. The present study was undertaken to analyze the properties of two knitted and crimped polyester arterial prototype prostheses, one with and the other without a gelatin coating as sealant. Two commercial controls were also included in the study, namely the uncoated knitted polyester vascular prosthesis VP1200K, and its sealed version, the gelatin coated polyester knitted Gelsoft device, manufactured by Vascutek Ltd., Scotland, UK. In vitro testing consisted of analyzing the and marphology of the yam and fabric structures, and measuring the physical and mechanical properties of the grafts, including the water prow.ability, the longitudinal and radial campliance, and the suture retention strength. In order to the different properties of the four samples, tests were performed on the gelatin coated of sealed devices before and after gelatin removal. The results provided a useful comparison between the prototypes and the commercial contorl devices. The latter used ten times the amount of gelatin which had been applied as a coating in order to achieve the same low level of impemeability to water. The different amounts of gelatin also explained the different mechanical performance, such as compliance, for these prototype and control prostheses.
