Angioplasty

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Angioplasty procedure. Javier Larrea/age fotostock/Getty Images

Angioplasty – also called “percutaneous transluminal coronary angioplasty,” or PTCA – is a catheterization procedure aimed at relieving blockages within arteries, most commonly the coronary arteries. Angioplasty works by inflating a tiny balloon at the site of an atherosclerotic plaque, flattening the plaque and reducing the stenosis (blockage) within the artery. In almost every case angioplasty is accompanied by insertion of a stent.

How is Angioplasty Done?

To perform an angioplasty, the doctor uses a catheter (a long, thin, flexible tube) that has a deflated balloon attached to it. He/she passes the catheter across the narrowed portion of the artery, and expands the balloon under pressure. The expanded balloon compresses the plaque that is causing the blockage. When the balloon is deflated and removed, the plaque remains at least partly compressed, so the blockage is reduced.

In most cases in which angioplasty is performed on a coronary artery blockage, a stent is inserted at the same time. The stent is placed over the balloon before it is inserted. Then, when the balloon is inflated, the plaque is compressed and the stent is expanded at the same time. When the deflated balloon is removed, the stent is left in place, helping to keep the artery open.

When is Angioplasty Helpful?

Angioplasty is quite effective in reducing the symptoms of stable angina.

However, when compared to medical therapy in people with stable angina, angioplasty (whether or not a stent is used) has not been shown definitively to reduce the risk of myocardial infarction (heart attack), or to improve survival.

Angioplasty is often also used to treat patients with acute coronary syndrome (ACS).

When used in ACS, the available evidence more clearly shows that angioplasty and stenting help to improve overall cardiac outcomes.

What Are the Main Complications of Angioplasty

The most common complication following angioplasty alone is restenosis – the formation of a new blockage at the site of the procedure. Restenosis is a relatively gradual process caused by the new growth of tissue - probably in response to the trauma produced in and around the vessel wall by the angioplasty itself. The incidence of restenosis has been greatly diminished by the use of stents, especially drug-eluting stents (DES) - which are coated with medication that inhibits the growth of tissue, thus reducing restenosis.

Before the era of stents, late restenosis occurred in nearly 30% of patients who had angioplasty. The use of bare metal stents reduced this risk to about 15%, and drug eluting stents reduced it further to around 10%.

A less common problem, but a more devastating one, is thrombosis (blood clotting) at the site of angioplasty/stenting.

Stent thrombosis is a sudden and often catastrophic event, which typically produces acute and complete obstruction of the affected artery. Thrombosis is most commonly seen soon after the angioplasty procedure (that is, within days to weeks). However, when a stent has been inserted during the angioplasty (which is almost always the case), a low risk of thrombosis persists for several months to several years after the procedure. The risk of thrombosis is significantly reduced by the use of anti-platelet drugs - which themselves carry some risk.

In addition to the coronary arteries, angioplasty can also be used in arteries in other areas of the body affected by atherosclerosis, such as the carotid arteries (which supply the brain), the renal arteries (which supply the kidneys) and the leg arteries.

Sources:

Smith, SC Jr, Feldman, TE, Hirshfeld, JW Jr, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 2006; 47:e1. Available at: http://content.onlinejacc.org/cgi/content/full/47/1/e1 (accessed September 10, 2008).

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