Local release of metal ions from endovascular metallic implants in the human biological specimens: An overview of in vivo clinical implications

Abstract

Cardiovascular heart disease is one of the leading healthcare problems in this present era and need much care to prevent from this problem. The main reason for this problem is the accumulation of fats or plaque that blocks coronary arteries of heart which in turn resist the flow of blood to the heart walls and cause serious complications. The advancement in biomedical engineering and fabrication technology along with implantation technique made it possible and convenient to minimize the problems of coronary heart diseases. Small medical implantable metallic devices are used in contemporary cardio logical practice. Metals constitute the main components of these cardiovascular medical devices. A complication to the intervention and especially to bare metal stents is in-stent restenosis. Furthermore, limited information is available regarding the condition of stent surfaces and their interaction with vascular tissue following implantation. Corrosion of stents presents two main risks: release of metal ions into tissue and bodily fluids and deterioration of the mechanical properties of stents which may contribute to fracture. Release of metal ions could alter the local tissue environment leading to up-regulation of inflammatory mediators and promote in-stent restenosis. In this article we have reviewed studies that have characterized in vivo corrosion of cardiovascular metallic devices which is associated with release of metal ions into tissue and bodily fluids. This review further reports a possible association between stents and metal contact allergy. Potential clinical consequences of these observations are discussed.

Multilevel Assessment of Stent-Induced Inflammation in the Adjacent Vascular Tissue

“…The clinical community, in the majority, finds it ambiguous that state-of-the-art cardiovascular stents wear down in a way that could influence human homeostasis or implant performance and longevity. However, several reports indicate that nanoparticles and ions leaching from metal implants modulate inflammatory cell processes and in the case of cardiovascular stents, this may be a contributing factor to neointimal thickening and ISR. ,,,,− …”

“…However, several reports indicate that nanoparticles and ions leaching from metal implants modulate inflammatory cell processes and in the case of cardiovascular stents, this may be a contributing factor to neointimal thickening and ISR. 5 , 8 , 9 , 18 , 57 − 59 …”

A Predictive Toxicokinetic Model for Nickel Leaching from Vascular Stents

“…This creates a pathway for the exposure of metal ion-rich phases to the in vivo environment, ultimately causing elevated ion release and reduced resistance to pitting. , Experimental and clinical data, collectively reported by the U.S. Food and Drug Administration (FDA), suggest that metal implants experience different degrees of wear and corrosion due to the mechanical and biochemical environment at the specific site of implantation . For vascular (coronary and peripheral) stents, the in vivo setting, comprising complex vascular geometries and dynamic loading profiles, can affect corrosion susceptibility and result in surface damage or a change in ion diffusion kinetics. − Allergenic, toxic/cytotoxic, or carcinogenic substances may be released into the body during the degradation processes, which contaminate the surrounding tissue and/or the bloodstream and may cause several adverse local as well as systemic effects. − The majority of metal alloys used for stent manufacturing contain high levels of nickel, which is metallurgically necessary to impart enhanced mechanical properties but may lead to several adverse health effects if leached in high concentrations…”

“… 10 − 16 Allergenic, toxic/cytotoxic, or carcinogenic substances may be released into the body during the degradation processes, which contaminate the surrounding tissue and/or the bloodstream and may cause several adverse local as well as systemic effects. 17 − 20 The majority of metal alloys used for stent manufacturing contain high levels of nickel, which is metallurgically necessary to impart enhanced mechanical properties but may lead to several adverse health effects if leached in high concentrations. 9…”

Biomaterials as Implants in the Orthopedic Field for Regenerative Medicine: Metal versus Synthetic Polymers

“…During corrosion processes, allergenic, toxic/cytotoxic, or carcinogenic species such as Ni, Co, and Cr, may be released into the body. Moreover, different mechanisms of corrosion can contribute to implant loosening and failure [ 22 , 23 , 24 ]. Consequently, bio-implants often undergo corrosion and/or solubility testing before receiving approval from regulatory bodies [ 5 ].…”