stent

Stent

A stent is a mesh 'tube' inserted into a natural passage/conduit in the body to prevent or counteract a disease-induced, localized flow constriction.

The term may also refer to a tube used to temporarily hold such a natural conduit open to allow access for surgery.

A stent graft is a tubular device composed of special fabric supported by a rigid structure, the stent, which is usually metal. An average stent on its own has no covering, and is usually just a metal mesh. Although there are many types of stents, these stents are used mainly for vascular interventions.

The device is used primarily in endovascular surgery. Stent grafts support weak points in arteries; such a point is commonly known as an aneurysm. Stent grafts are most commonly used to repair an abdominal aortic aneurysm, in a procedure called an EVAR. The theory behind the procedure is that once in place inside the aorta, the stent graft acts as a false lumen through which blood can travel, instead of flowing into the aneurysm sack.

Stent grafts are also commonly placed within grafts and fistulas used for dialysis. These accesses can become obstructed over time, or develop aneurysms similar to those in other blood vessels. A stent graft can be used in either situation to create an open lumen and prevent blood from flowing around it.