stents

A stent is a small tubular device implanted into a hollow structure to keep it open and provide support. In medicine, stents are widely used to treat narrowed arteries, most commonly the coronary arteries during percutaneous coronary intervention (PCI) for atherosclerotic disease.

Stents come in bare-metal and drug-eluting forms. They can be balloon-expandable or self-expanding, and are made from metals such as stainless steel, cobalt-chromium, or nitinol. Drug-eluting stents release antiproliferative drugs (e.g., sirolimus, paclitaxel) to reduce scar tissue. Biodegradable stents dissolve over time.

During PCI, a catheter is guided to the blockage, the artery is widened with a balloon, and the stent is pressed against the wall. Patients usually take aspirin and a second antiplatelet drug for months to prevent thrombosis.

Indications include coronary artery disease and peripheral artery disease; stents are also used in biliary, urinary, or esophageal ducts to relieve obstructions.

Risks include restenosis, stent thrombosis, bleeding, infection, and vessel injury. Bare-metal stents have higher restenosis risk than drug-eluting types; prolonged antiplatelet therapy reduces thrombosis risk.

History: stents were developed in the late 20th century, and became common in the 1990s. Ongoing work focuses on safer materials, coatings, and bioresorbable designs.