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Stents
In medicine, a stent is a metal or plastic tube inserted into the lumen of an anatomic vessel or duct to keep the passageway open, and stenting is the placement of a stent. A wide variety of stents are used for different purposes, from expandable coronary, vascular and biliary stents, to simple plastic stents that allow urine to flow between kidney and bladder. "Stent" is also used as a verb to describe the placement of such a device, particularly when a disease such as atherosclerosis has pathologically narrowed a structure such as an artery. A stent is different from a shunt. A shunt is a tube that connects two previously unconnected parts of the body to allow fluid to flow between them. Stents and shunts can be made of similar materials, but perform two different tasks. Stent types Etymology The current accepted origin of the word ''stent'' is that it derives from the name of an English dentist, Charles Thomas Stent (1807–1885), notable for his advances in the fie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug-eluting Stent
A drug-eluting stent (DES) is a peripheral or coronary stent (a scaffold) 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. Drug-eluting stents in current clinical use were approved by the FDA after clinical trials showed they were statistically superior to bare-metal stents for the treatment of native coronary artery narrowings, having lower rates of major adverse cardiac events (usually defined as a composite clinical endpoint of death + myocardial infarction + repeat intervention because of restenosis). The first drug-eluting stents to be approved in Europe and the U.S. were coated with paclitaxel or an mTOR inhi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Stent
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 (chest pain) and have been shown to improve survivability and decrease adverse events in an acute myocardial infarction. Similar stents and procedures are used in non-coronary vessels (e.g., in the legs in peripheral artery disease). Medical uses Arterial Stenting 3D Medical Animation An artery with a stent follows the same steps as other angioplasty procedures with a few important differences. The interventional cardiologist uses angiography to assess the location and estimate the size of the blockage ("lesion") by injecting a contrast medium through the guide catheter and viewing the flow of blood through the downstream coronary arteries. Intrav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Stent
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 (chest pain) and have been shown to improve survivability and decrease adverse events in an acute myocardial infarction. Similar stents and procedures are used in non-coronary vessels (e.g., in the legs in peripheral artery disease). Medical uses Arterial Stenting 3D Medical Animation An artery with a stent follows the same steps as other angioplasty procedures with a few important differences. The interventional cardiologist uses angiography to assess the location and estimate the size of the blockage ("lesion") by injecting a contrast medium through the guide catheter and viewing the flow of blood through the downstream coronary arteries. Intrav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bare-metal Stent
A bare-metal stent is a stent made of thin, uncoated (bare) metal wire that has been formed into a mesh-like tube. The first stents licensed for use in cardiac arteries were bare metal – often 316L stainless steel. More recent "second generation" bare-metal stents have been made of cobalt chromium alloy.Nikam N et al. Advances in stent technologies and their effect on clinical efficacy and safety. Med Devices (Auckl). 2014 Jun 3;7:165-78. While plastic stents were first used to treat gastrointestinal conditions of the esophagus, gastroduodenum, biliary ducts, and colon, bare-metal stent advancements led to their use for these conditions starting in the 1990s.Park JS, Jeong S, Lee DH. Recent Advances in Gastrointestinal Stent Development. Clin Endosc. 2015 May; 48(3): 209–215. Drug-eluting stents are often preferred over bare-metal stents because the latter carry a higher risk of restenosis, the growth of tissue into the stent resulting in vessel narrowing.Palmerini T et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angioplasty
Angioplasty, is 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 (a balloon 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. The word is composed of the combining forms of the Greek words ἀνγεῖον ' "vessel" or "cavity" (of the human body) and πλάσσω ' "form" or "mould". Uses and indications Coronary angioplasty A coronary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bare-metal Stent
A bare-metal stent is a stent made of thin, uncoated (bare) metal wire that has been formed into a mesh-like tube. The first stents licensed for use in cardiac arteries were bare metal – often 316L stainless steel. More recent "second generation" bare-metal stents have been made of cobalt chromium alloy.Nikam N et al. Advances in stent technologies and their effect on clinical efficacy and safety. Med Devices (Auckl). 2014 Jun 3;7:165-78. While plastic stents were first used to treat gastrointestinal conditions of the esophagus, gastroduodenum, biliary ducts, and colon, bare-metal stent advancements led to their use for these conditions starting in the 1990s.Park JS, Jeong S, Lee DH. Recent Advances in Gastrointestinal Stent Development. Clin Endosc. 2015 May; 48(3): 209–215. Drug-eluting stents are often preferred over bare-metal stents because the latter carry a higher risk of restenosis, the growth of tissue into the stent resulting in vessel narrowing.Palmerini T et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitinol
Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Different alloys are named according to the weight percentage of nickel; e.g., Nitinol 55 and Nitinol 60. It exhibits the shape memory effect and superelasticity at different temperatures. Nitinol alloys exhibit two closely related and unique properties: the shape memory effect and superelasticity (also called pseudoelasticity). Shape memory is the ability of Nitinol to undergo deformation at one temperature, stay in its deformed shape when the external force is removed, then recover its original, undeformed shape upon heating above its "transformation temperature". Superelasticity is the ability for the metal to undergo large deformations and immediately return to its undeformed shape upon removal of the external load. Nitinol can deform 10–30 times as much as ordinary metals and return to its original shape. Whether Nitinol be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endovascular Aneurysm Repair
Endovascular aneurysm repair (EVAR) is a type of minimally-invasive endovascular surgery used to treat pathology of the aorta, most commonly an abdominal aortic aneurysm (AAA). When used to treat thoracic aortic disease, the procedure is then specifically termed TEVAR for "thoracic endovascular aortic/aneurysm repair." EVAR involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. In 2003, EVAR surpassed open aortic surgery as the most common technique for repair of AAA, and in 2010, EVAR accounted for 78% of all intact AAA repair in the United States. Medical uses Standard EVAR is appropriate for aneurysms that begin below the renal arteries, where there exists an adequate length of normal aorta (the ''"proximal aortic neck"'') for reliable attachment of the endograft without leakage of blood around the device ("'' endoleak''"). If the proximal aortic neck is also involved with the aneurysm, the patient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenosis
A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture'' as a term is usually used when narrowing is caused by contraction of smooth muscle (e.g. achalasia, prinzmetal angina); ''stenosis'' is usually used when narrowing is caused by lesion that reduces the space of lumen (e.g. atherosclerosis). The term coarctation is another synonym, but is commonly used only in the context of aortic coarctation. Restenosis is the recurrence of stenosis after a procedure. Types The resulting syndrome depends on the structure affected. Examples of vascular stenotic lesions include: * Intermittent claudication (peripheral artery stenosis) * Angina ( coronary artery stenosis) * Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes) * Renal artery stenosis The types of sten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrombosis
Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thrombocytes) and fibrin to form a blood clot to prevent blood loss. Even when a blood vessel is not injured, blood clots may form in the body under certain conditions. A clot, or a piece of the clot, that breaks free and begins to travel around the body is known as an embolus. Thrombosis may occur in veins (venous thrombosis) or in arteries (arterial thrombosis). Venous thrombosis (sometimes called DVT, deep vein thrombosis) leads to a blood clot in the affected part of the body, while arterial thrombosis (and, rarely, severe venous thrombosis) affects the blood supply and leads to damage of the tissue supplied by that artery (ischemia and necrosis). A piece of either an arterial or a venous thrombus can break off as an embolus, which could ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femoral Artery
The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the femoral triangle. It enters and passes through the adductor canal, and becomes the popliteal artery as it passes through the adductor hiatus in the adductor magnus near the junction of the middle and distal thirds of the thigh. Structure The femoral artery enters the thigh from behind the inguinal ligament as the continuation of the external iliac artery. Here, it lies midway between the anterior superior iliac spine and the symphysis pubis (Mid-inguinal point). Segments In clinical parlance, the femoral artery has the following segments: *The common femoral artery (CFA) is the segment of the femoral artery between the inferior margin of the inguinal ligament and the branching point of the deep femoral artery/profunda femoris artery. Its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
