Vascular stent

Guidewires, mechanical heart-valve housings and struts, biologic heart-valve stents, vascular stents, vena cava umbrellas, artificial heart housings, pacemaker leads, leads for implantable electrical stimulators, surgical staples, supereleastic properties of some nickel-titanium formulations, shape memory properties of some Ni titanium formulation, radiopaque markers... 

Capoccia L, Sbarigia E, Speziale F. Monolateral sialadenitis following iodinated contrast media administration for carotid artery stenting. Vascular 2010 18(1) 34-6. 

Menna D, Capoccia L, Rizzo AR, Stoarigia E, Speziale F. An atypical case of contrast-induced encephalopathy after carotid artery stenting. Vascular April 2013 21(2) 109-12. 

Coated or fabricated medical devices Catheters Stents Vascular grafts Extracorporeal circuits Dialysis membranes Biomedical sensors Platelet function via aggregation... 

Restenosis is the phenomenon of vascular reocclusion postangioplasty or stent. 

Self-expanding stents with a higher radial force (e.g., WingSpan, Boston Scientific Corp.) will probably play a key role in acute stroke cases related to intracranial atherosclerotic disease. Antegrade flow is essential for the maintenance of vascular patency, as particularly evident in patients with severe proximal stenoses who commonly develop rethrombosis after vessel recanalization. Furthermore, stenting of the proximal vessels may be required in order to gain access to the intracranial thrombus with other mechanical devices or catheters. In a recent series, 23 of 25 patients (92%) with acute n = 15) or subacute n = 10) ICA occlusions were successfully revascularized with this technique. " ... 

Other agents such as actinomycin D, C-Myc antisense, dexamethasone, and matrix metalloproteinase inhibitors, aimed at altering inflammatory and smooth muscle actions in the biological repair response to vascular injury, are being evaluated. The success of these devices depends upon multiple issues, including stent platform, carrier, drug properties, and pharmacokinetic profile (18-26). Large randomized, controlled trials, demonstrate a restenosis rate of 5% to 10% with DES (27). 

Rogers C, Tseng DY, Squire JC, Edelman ER. Ballon-artery interactions during stent placement a finite element analysis approach to pressure, compliance, and stent design as contributors to vascular injury. Circ Res 1999 84 378-383. 

Fattori R, Piva T. Drug-eluting stents in vascular intervention. Lancet 2003 361 247-249. 

One of the most commonly used medical devices is the stent, (Fig. 21.1), small metallic structures that are expanded in blood vessels, functioning to maintain the patency (freedom from obstruction) of the vessel in which it is placed. Although the first use of stents was in vasculature (blood vessel systems), more recent applications include, for example, implantation between two vertebrae to increase the rigidity of the spine. A typical vascular stent is placed in its anatomical location and then either plastically deformed/expanded (stainless steel) or allowed to expand to a predetermined size, as a consequence of shape memory (nitinol). 

Biomedical Applications—CNTs allow cells to grow on and over them without adherence to the nanotubes and without toxic reaction. Potential applications range from their use within coatings and composites to be used within the body, for prosthetics, and in the construction of vascular stents and neuron growth and regulation. 

Clopidogrel is indicated for prevention of vascular ischaemic events in patients with symptomatic atherosclerosis. It is also used, along with aspirin, for the prevention of thromboembolism after placement of an intracoronary stent. Platelet inhibition can be demonstrated two hours after a single dose of oral clopidogrel, but the onset of action is slow, so that a loading-dose is usually administered. Although rare, severe neutropenia and also thrombotic thrombocytopenic purpura may occur. 

Artificial biologies, whelher soff or hard, can be categorized as eifher temporary (short term) or permanent (long term) in their intended application. Most, but certainly not all, polymers for biomedical applications are of the short-term type and include sutures, drug delivery devices, temporary vascular grafts and stents, tissue scaffolds. 

Originality Although diazeniumdiolated polymers have been used in vascular stents,... 

Preparation of a diazeniumdiolated polymer-coated vascular stent... 

A vascular stent was coated with the step 1 product and then placed in a 13 mm x 100 mm glass test tube and treated with 10 ml 3% sodium methoxide in methanol. 

PS/PIB/PS block copolymers have been shown to be vascularly compatible. When loaded with paclitaxel and coated on a coronary stent, the composite can deliver the drug directly to arterial walls. 

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