Stent

A stent is a tubular medical device placed into a vessel or duct to keep the lumen open and prevent collapse or recoil after intervention. The most common use is in coronary arteries after angioplasty to treat narrowed or blocked arteries, but stents are also used in peripheral arteries and in ducts such as the biliary, esophageal, ureteral, and airway passages.

Stents come in several designs and materials. Bare metal stents provide a scaffold without drugs, while drug-eluting stents are coated with antiproliferative medications to reduce tissue growth and restenosis. Biodegradable or bioresorbable stents are designed to dissolve over time. Stents may be balloon-expandable, expanded by inflating a balloon, or self-expanding, typically made from nitinol or other alloys. Common materials include stainless steel, cobalt-chromium, and nitinol.

Indications include treatment of vascular stenosis or occlusion to relieve symptoms and improve blood flow, prevention of vessel recoil after angioplasty, and palliation of malignant obstructions in the biliary, esophageal, gastric, ureteral, or airway tracts. The procedure generally involves delivering the stent via a catheter to the target site under imaging guidance, followed by deployment to restore or maintain lumen patency.

Potential complications include stent thrombosis or restenosis, stent migration or fracture, bleeding, infection, and allergic reactions. Management may involve antiplatelet therapy, further interventions, or replacement of the stent. Follow-up imaging or endoscopic assessment is used to monitor function and detect adverse events. Stents have contributed to improved outcomes in many conditions, but device choice and duration of therapy depend on the clinical setting and patient risk factors.