Stent (coronary stent implant)
In medicine, a stent is an expandable wire mesh tube that is inserted into a hollow structure of the body to keep it patent (i.e. open).
Stents are used on diverse structures such as the esophagus, trachea, or blood vessels. Prior to use, a stent is collapsed to a small diameter; when brought into place it is expanded using an inflatable balloon and is then held in place by its own tension. Stents are usually inserted by endoscopy or other procedures less invasive than a surgical operation, which makes them suitable for patients with advanced disease for whom an operation might be too dangerous. Stents may consist of wire mesh alone, or be covered by a tissue lining.
A coronary stent implant is a therapeutic cardiac procedure that involves placing a stent, which is a small mesh-like wire tube in a narrowed artery. This procedure is similar to angioplasty in many ways. However, the stent is left permanently in place in the artery to act as a scaffold to help keep the artery open. Usually, an angioplasty procedure is performed first. The balloon inflations help open the artery to allow the stent to be placed easily. The angioplasty catheter is removed. A different angioplasty catheter with a stent crimped on the balloon is advanced into the artery and carefully positioned at the blockage. The angioplasty balloon is inflated which opens the stent and presses it into the artery wall. The stent holds the artery open and helps reduce the rate of restenosis (a recurrence of the narrowing within the artery).
The stent procedure will open blocked arteries and improve blood flow to your heart. It relieves symptoms, improves exercise duration, and in some cases stops or prevents heart attacks. It is more effective than medications in relieving symptoms in patients with a blockage in one artery. Following a stent, many patients can stop or reduce their number of heart medications. Coronary stents have been one of the most significant advances in cardiology in recent years. Compared to angioplasty, stents reduce the incidence of sub-optimal results and complications such as artery injury and emergency bypass surgery. Most importantly, stents significantly reduce the chance of recurrence of the blockage or restenosis. This means fewer patients will need a repeat procedure.
Stent procedure uses a wire mesh tube (a stent) to prop open an artery that has recently been cleared using angioplasty. The stent is collapsed to a small diameter, placed over an angioplasty balloon catheter and moved into the area of the blockage. When the balloon is inflated, the stent expands, locks in place and forms a rigid support to hold the artery open. The stent remains in the artery permanently, holds it open, improves blood flow to the heart muscle and relieves symptoms (usually chest pain).
The stent procedure is fairly common, sometimes used as an alternative to coronary artery bypass surgery. A stent may be used as an alternative or in combination with angioplasty. Certain features of the artery blockage make it suitable for using a stent, such as the size of the artery and location of the blockage.
The risks of stents are low. The risks include all of the complications noted for cardiac catheterization, but some of the risks, specifically heart attack and emergency bypass surgery, are higher because angioplasty and stent are more complex procedures. The risks include injury or tearing of an artery which can cause the artery to close. This is often successfully treated with continued angioplasty or stent. Rarely, this is difficult to treat and three percent of patients may have a heart attack and one percent may need emergency bypass surgery. A cardiac surgery team is available at the Inova Heart Center if needed. In three to five percent of patients the procedure is unsuccessful because the catheter cannot be advanced to the blockage or the artery cannot be fully opened. This can occur when the artery is small, has calcium deposits, or has severe bends.
A stent is the right procedure for most patients because it lowers the chance of restenosis. It is performed in about 70% of patients who need an invasive interventional procedure. Stents are not often used for blockages located in small arteries, with calcium deposits, that involve a branch point, or are long.