Angioplasty

Angioplasty is a minimally invasive procedure that uses a balloon-tipped catheter to reopen narrowed or blocked blood vessels, most often those affected by atherosclerosis. A guidewire is first threaded to the blockage, then a deflated balloon catheter is advanced over it and inflated to a set diameter. This inflation stretches the vessel wall and the surrounding muscle, restoring better blood flow. A stent is sometimes placed during the inflation to help keep the vessel open, after which the balloon is deflated and removed. The term now covers a wide range of percutaneous vascular treatments.

**Uses and indications**

**Coronary angioplasty** This procedure treats narrowed coronary arteries in coronary heart disease, where cholesterol-filled plaques build up through atherosclerosis. Known as percutaneous coronary intervention, it is a non-surgical way to improve blood supply to the heart. It is used for unstable angina, NSTEMI, STEMI, and spontaneous coronary artery perforation. In stable coronary disease, it can relieve chest pain (angina), improve physical function, and enhance quality of life.

**Peripheral angioplasty** Peripheral angioplasty opens blood vessels outside the heart, most commonly those narrowed by peripheral artery disease in the abdomen, legs, or kidneys. It is often performed alongside a guidewire, peripheral stenting, and atherectomy.

**Chronic limb-threatening ischemia** For advanced peripheral artery disease, angioplasty can ease the leg pain known as claudication. A study comparing bypass surgery first versus angioplasty first in severe lower limb ischemia found that angioplasty caused fewer short-term complications, but bypass surgery offered better long-term results. Based on that study, ACCF/AHA guidelines recommend balloon angioplasty only for patients with a life expectancy of two years or less, or those lacking an autogenous vein. For patients expected to live longer than two years or who have a suitable vein, bypass surgery is preferred.

**Renal artery angioplasty** Renal artery stenosis, linked to high blood pressure and kidney function loss, can be treated with angioplasty, with or without stenting. There is a weak recommendation for this procedure in patients who also have flash edema or congestive heart failure.

**Carotid angioplasty** Carotid artery stenosis can be managed with angioplasty and stenting in patients at high risk for carotid endarterectomy. Although endarterectomy is usually the first choice, stenting is indicated for certain patients, such as those with radiation-induced stenosis or a carotid lesion unsuitable for surgery.

**Venous angioplasty** Angioplasty treats venous stenosis in dialysis access, with drug-coated balloon angioplasty showing better 6- and 12-month patency than standard balloon angioplasty. It is also occasionally used for residual subclavian vein stenosis after thoracic outlet decompression surgery. There is a weak recommendation for deep venous stenting in obstructive chronic venous disease.

**Contraindications** Angioplasty requires a suitable access vessel—typically the femoral or radial artery, or femoral vein—for the wires and catheters. If no vessel of sufficient size and quality exists, the procedure is contraindicated. Small vessel diameter, posterior calcification, occlusion, hematoma, or a prior bypass origin can make access too difficult. Percutaneous coronary angioplasty is contraindicated in left main coronary artery disease due to the risk of spasm, and is not recommended for coronary stenosis below 70%, as such narrowing is not hemodynamically significant.

**Technique** Vascular access is usually gained percutaneously using the Seldinger technique to insert an introducer sheath. Fluoroscopy—using X-ray or magnetic resonance imaging with radiopaque contrast dye—guides angled wires and catheters to the target area in real time. A tapered guidewire is chosen for small occlusions, an intermediate type for tortuous arteries or very narrow channels, and a stiff wire for hard, dense, blunt blockages. To treat a narrowing, a wire is passed through the stenosis, and a balloon catheter is advanced over it (over-the-wire technique) to the correct position, confirmed by fluoroscopy. The balloon is then inflated with water mixed with contrast dye to pressures 75 to 500 times normal blood pressure (6 to 20 atmospheres); most coronary angioplasties require less than 10 atmospheres. A stent may or may not be placed. After inflation, the balloon is deflated and withdrawn.