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A drug-eluting stent (DES) is a tube made of a mesh-like material used to treat narrowed arteries in medical procedures both mechanically (by providing a supporting scaffold inside the artery) and pharmacologically (by slowly releasing a pharmaceutical compound). A DES is inserted into a narrowed artery using a delivery catheter usually inserted through a larger artery in the groin or wrist. The stent assembly carries the DES mechanism towards the front of the catheter, and is usually composed of the collapsed stent over a collapsed polymeric balloon mechanism which is inflated to expand the stent once in position. The stent expands and embeds into the occluded artery wall, keeping the artery open, thereby improving blood flow. The mesh design allows for stent expansion and also for new healthy vessel endothelial cells to grow through and around it, securing it in place.
A DES differs from other types of stents in that it not only keeps a blood vessel open mechanically but is also able to deliver a small amount of a drug directly into the blood vessel wall for a limited period of time. The drug is chemically attached to the wall of the stent. After the stent has been positioned and the clogged vessel reopened, the stent delivers a small amount of the drug into the blood vessel interior wall. This allows time for stent embedding and reduces the chances of the stent interior becoming blocked. Only a very small amount of tissue growth inhibiting drug is carried by the stent, just enough to allow time for blood vessel embedding and for it to function mechanically to keep a vessel open.

DESs are commonly used in the treatment of narrowed arteries in the heart (coronary artery disease (CAD)), but also elsewhere in the body, especially the legs (peripheral artery disease). Since coronary stenting became routine following US FDA approval in 1994, it has matured into a primary minimally invasive treatment tool in managing CAD. Coronary artery stenting is inherently tied to percutaneous coronary intervention (PCI) procedures. PCI is a minimally invasive procedure performed via a catheter (not by open-chest surgery), it is the medical procedure used to place a DES in narrowed coronary arteries. PCI procedures are performed by an interventional cardiologist using fluoroscopic imaging techniques to see the location of the required DES placement. PCI uses larger peripheral arteries in the arms or the legs to thread a DES catheter through the arterial system and place the stent in the narrowed coronary artery. Multiple stents may be used depending on the degree of blockage and the number of diseased coronary arteries that need treatment.
The first DES approved for clinical use was the sirolimus-eluting Cypher stent, which received CE marking in Europe in 2002 and US FDA approval in 2003. Paclitaxel-eluting stents followed in 2004. DES were developed to address the high rates of in-stent restenosis (20-40%) seen with earlier bare-metal stents (BMS); DES reduced this rate to approximately 5-10%. Current-generation DES use thinner struts made of cobalt-chromium or platinum-chromium alloys, biocompatible or biodegradable coatings, and limus family drugs such as everolimus and zotarolimus.
Risks of DES placement include stent thrombosis (approximately 0.7% at one year), bleeding, and allergic reactions to contrast agents. An alternative to PCI with DES is coronary artery bypass graft surgery, which may be preferred for patients with complex multi-vessel disease. The use of DES has been accompanied by debate over potential overuse in patients with stable coronary artery disease, where optimal medical therapy alone may provide comparable outcomes.