Angioplasty, also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A stent may be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn. Angioplasty has come to include all manner of vascular interventions that are typically performed percutaneously.
A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes.
Restenosis is the recurrence of stenosis, a narrowing of a blood vessel, leading to restricted blood flow. Restenosis usually pertains to an artery or other large blood vessel that has become narrowed, received treatment to clear the blockage and subsequently become renarrowed. This is usually restenosis of an artery, or other blood vessel, or possibly a vessel within an organ.
Coronary thrombosis is defined as the formation of a blood clot inside a blood vessel of the heart. This blood clot may then restrict blood flow within the heart, leading to heart tissue damage, or a myocardial infarction, also known as a heart attack.
Percutaneous coronary intervention (PCI) is a non-surgical procedure used to treat narrowing of the coronary arteries of the heart found in coronary artery disease. The process involves combining coronary angioplasty with stenting, which is the insertion of a permanent wire-meshed tube that is either drug eluting (DES) or composed of bare metal (BMS). The stent delivery balloon from the angioplasty catheter is inflated with media to force contact between the struts of the stent and the vessel wall, thus widening the blood vessel diameter. After accessing the blood stream through the femoral or radial artery, the procedure uses coronary catheterization to visualise the blood vessels on X-ray imaging. After this, an interventional cardiologist can perform a coronary angioplasty, using a balloon catheter in which a deflated balloon is advanced into the obstructed artery and inflated to relieve the narrowing; certain devices such as stents can be deployed to keep the blood vessel open. Various other procedures can also be performed.
A drug-eluting stent (DES) is a peripheral or coronary stent placed into narrowed, diseased peripheral or coronary arteries that slowly release a drug to block cell proliferation. This prevents fibrosis that, together with clots (thrombi), could otherwise block the stented artery, a process called restenosis. The stent is usually placed within the peripheral or coronary artery by an interventional cardiologist or interventional radiologist during an angioplasty procedure.
A foreign body reaction (FBR) is a typical tissue response to a foreign body within biological tissue. It usually includes the formation of a foreign body granuloma. Tissue-encapsulation of an implant is an example, as is inflammation around a splinter. Foreign body granuloma formation consists of protein adsorption, macrophages, multinucleated foreign body giant cells, fibroblasts, and angiogenesis. It has also been proposed that the mechanical property of the interface between an implant and its surrounding tissues is critical for the host response.
The history of invasive and interventional cardiology is complex, with multiple groups working independently on similar technologies. Invasive and interventional cardiology is currently closely associated with cardiologists, though the development and most of its early research and procedures were performed by diagnostic and interventional radiologists.
A coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in the treatment of coronary heart disease. It is used in a procedure called percutaneous coronary intervention (PCI). Coronary stents are now used in more than 90% of PCI procedures. Stents reduce angina and have been shown to improve survival and decrease adverse events in an acute myocardial infarction.
Zotarolimus is an immunosuppressant. It is a semi-synthetic derivative of sirolimus (rapamycin). It was designed for use in stents with phosphorylcholine as a carrier. Zotarolimus, or ABT-578, was originally used on Abbott's coronary stent platforms to reduce early inflammation and restenosis; however, Zotarolimus failed Abbott's primary endpoint to bring their stent/drug delivery system to market. The drug was sold/distributed to Medtronic for use on their stent platforms, which is the same drug they use today. Coronary stents reduce early complications and improve late clinical outcomes in patients needing interventional cardiology. The first human coronary stent implantation was first performed in 1986 by Puel et al. However, there are complications associated with stent use, development of thrombosis which impedes the efficiency of coronary stents, haemorrhagic and restenosis complications are problems associated with stents.
Nitinol biocompatibility is an important factor in biomedical applications. Nitinol (NiTi), which is formed by alloying nickel and titanium, is a shape-memory alloy with superelastic properties more similar to that of bone, when compared to stainless steel, another commonly used biomaterial. Biomedical applications that utilize nitinol include stents, heart valve tools, bone anchors, staples, septal defect devices and implants. It is a commonly used biomaterial especially in the development of stent technology.
Julio Palmaz is a doctor of vascular radiology at University of Texas Health Science Center at San Antonio. He studied at the National University of La Plata in Argentina, earning his medical degree in 1971. He then practiced vascular radiology at the San Martin University Hospital in La Plata before moving to the University of Texas Health and Science Center at San Antonio. He is known for inventing the balloon-expandable stent, for which he received a patent filed in 1985. It was recognized in Intellectual Property International Magazine as one of "Ten Patents that Changed the World" in the last century. His early stent research artifacts are now part of the medical collection of the Smithsonian Institution in Washington, DC. He continues to innovate on his initial designs, developing new endovascular devices.
In medicine, a stent is any device which is inserted into a blood vessel or other internal duct to expand it to prevent or alleviate a blockage. Traditionally, such devices are fabricated from metal mesh and remain in the body permanently or until removed through further surgical intervention. A bioresorbable stent serves the same purpose, but is manufactured from a material that may dissolve or be absorbed in the body.
Nicholas George Kounis is professor emeritus of cardiology in the University of Patras and scientific cardiology advisor at Saint Andrews State General Hospital Patras and at the Department of cardiology of University of Patras Medical School, Patras, Greece.
Genous is an endothelial progenitor cell (EPC) capture technology manufactured by OrbusNeich that promotes the accelerated natural healing of the vessel wall after stent implantation. The pro-healing technology has an antibody surface coating that captures circulating CD34+ endothelial progenitor cells to the device, forming a functional endothelial layer over the stent to protect against thrombus and minimize restenosis.
Biomaterials are materials that are used in contact with biological systems. Biocompatibility and applicability of surface modification with current uses of metallic, polymeric and ceramic biomaterials allow alteration of properties to enhance performance in a biological environment while retaining bulk properties of the desired device.
Biomaterials exhibit various degrees of compatibility with the harsh environment within a living organism. They need to be nonreactive chemically and physically with the body, as well as integrate when deposited into tissue. The extent of compatibility varies based on the application and material required. Often modifications to the surface of a biomaterial system are required to maximize performance. The surface can be modified in many ways, including plasma modification and applying coatings to the substrate. Surface modifications can be used to affect surface energy, adhesion, biocompatibility, chemical inertness, lubricity, sterility, asepsis, thrombogenicity, susceptibility to corrosion, degradation, and hydrophilicity.
Neointimal hyperplasia refers to proliferation and migration of vascular smooth muscle cells primarily in the tunica intima, resulting in the thickening of arterial walls and decreased arterial lumen space. Neointimal hyperplasia is the major cause of restenosis after percutaneous coronary interventions such as stenting or angioplasty. The term neointima is used because the cells in the hyperplastic regions of the vascular wall have histological characteristics of both intima and normal artery cells.
A dual therapy stent is a coronary artery stent that combines the technology of an antibody-coated stent and a drug-eluting stent. Currently, second-generation drug-eluting stents require long-term use of dual-antiplatelet therapy, which increases the risk of major bleeding occurrences in patients. Compared to drug-eluting stents, dual therapy stents have improved vessel regeneration and cell proliferation capabilities. As a result, dual therapy stents were developed to reduce the long-term need for dual-antiplatelet therapy.
Drug eluting implants encompass a wide range of bioactive implants that can be placed in or near a tissue to provide a controlled, sustained or on demand release of drug while overcoming barriers associated with traditional oral and intravenous drug administration, such as limited bioavailability, metabolism, and toxicity. These implants can be used to treat location-specific and surrounding illness and commonly use 3-D printing technologies to achieve individualized implants for patients.
