Transcatheter valve-in-valve implantation in failing bioprosthesis is an emerging field in cardio-vascular surgery and cardiology. If a valve plasty is not possible, a biological valve is implanted with limited durability. Due to valve degeneration repeated valve exchanges are necessary in some patients. To expand the lifetime of a bioprosthesis in the tricuspid position percutaneous transcatheter valve-in-valve implantation was introduced recently. This is a promising new catheter interventional technology. There are no published outcomes of repeat surgical, but overall early mortality after tricuspid valve replacement (TVR) was 37% in patients undergoing TVR after prior tricuspid valve (TV) repair. The off-label use of transcatheter aortic valve prostheses for tri-cuspid valve– in–valve implantation within dysfunctional surgical tricuspid valve bioprosthesis has been described in small reports but has become of interest nowadays.
Oxidative stress plays a major part in the development of chronic and degenerative diseases such as cancer, arthritis, aging, autoimmune disorders, cardiovascular and neurodegenerative diseases. Cardiovascular disease is the leading cause of death in the United States and Europe and is poised to become the most significant health problem worldwide. Reactive nitrogen species are involved in the regulation of cardiovascular motor tone, modulation of myocardial contractility, control of cell proliferation and inhibition of platelet activation, aggregation, and adhesion. Cellular constituents of our body are altered in oxidative stress conditions, resulting in various disease states. The oxidative stress can be effectively neutralized by enhancing cellular defenses in the form of antioxidants. To understand the mechanism of action of antioxidants, it is necessary to understand the generation of free radicals and their damaging reactions.
