metallstent

A metallstent, or metal stent, is a small cylindrical mesh implanted into a hollow organ or vessel to prevent collapse or constriction and to restore or maintain patency. Usually delivered via catheter and deployed by expansion, it acts as a scaffold that supports the vessel wall while healing occurs. Most metallstents are permanent implants, though some designs are bioresorbable and disappear over time.

Material choices include stainless steel, cobalt-chromium, platinum-chromium, and nitinol (nickel-titanium alloy) for self-expanding types. Metal stents are broadly categorized into bare-metal stents (BMS) and drug-eluting stents (DES), the latter coated with antiproliferative drugs such as sirolimus or paclitaxel to reduce restenosis. Stents can be balloon-expandable or self-expanding, the latter often made from nitinol.

Applications span cardiovascular and non-vascular areas. In medicine, metal stents are used to treat coronary artery disease and peripheral vascular disease, as well as obstructions in the biliary tract, esophagus, and airways. They provide immediate luminal gain and can accommodate complex lesions.

Implantation is performed during endovascular or endoscopic procedures. After coronary stenting, patients typically require antiplatelet therapy to minimize thrombosis risk. Drug-eluting stents reduce restenosis compared with bare-metal stents but carry a different bleeding risk profile and may delay endothelial healing. Newer designs include bioresorbable stents made from magnesium alloys or degradable polymers, which gradually resorb after maintaining patency.

Common complications include stent thrombosis, restenosis, stent fracture, migration, infection, and allergic reaction to metals. Long-term outcomes depend on lesion characteristics, device type, and adherence to antithrombotic therapy.