Angioplasty, Percutaneous Transluminal Coronary
Used to treat coronary artery disease, percutaneous transluminal coronary angioplasty (PTCA) offers some patients a nonsurgical alternative to coronary artery bypass surgery. PTCA is performed for occlusion that decreases the artery lumen by 70% or greater. In PTCA, a tiny balloon catheter is used to dilate a coronary artery that has been narrowed by atherosclerotic plaque.
With PTCA, hospitalization usually lasts 1 to 2 days, compared with a typical 5- to 7-day stay for coronary artery bypass. The patient is usually ambulatory within a day after PTCA and can typically return to work within a few weeks. Another advantage of PTCA is that it’s much less costly than coronary artery bypass.
However, PTCA is an option for only a select group of patients. Usually it’s indicated for patients who have myocardial ischemia, documented by an electrocardiogram (ECG) or thallium scan, and a lesion in the proximal portion of a single coronary artery. Recently, however, patients with multivessel disease, totally occluded coronary arteries, or acute myocardial infarction have undergone successful PTCA. In addition, patients who have had previous coronary artery bypass surgery, postthrombolytic therapy with high-grade stenosis, or who are at high risk for complications associated with coronary artery bypass surgery may be candidates for PTCA. However, patients undergoing PTCA must also be acceptable candidates for coronary artery bypass surgery in case PTCA isn’t successful and emergency coronary artery bypass surgery becomes necessary. Emergency coronary artery bypass surgery occurs in about 6% of PTCA patients.
Procedure
Although PTCA is performed in the cardiac catheterization laboratory, a surgical team must stand by during the procedure in case emergency coronary artery bypass is required. Coronary arteriography is usually performed to compare the size and exact location of the lesion with those on previous films. As a precaution, temporary pacemaker wires are inserted in case transient heart block occurs during the procedure.
After preparing and anesthetizing the catheter insertion site, the surgeon inserts a guide wire into the femoral artery by a percutaneous approach (other sites, such as the brachial artery with a cutdown approach, may be used instead). The surgeon threads the catheter into the coronary artery with the help of fluoroscopy and confirms the presence of the lesion by angiography.
Next, the surgeon introduces a small double-lumen balloon-tipped catheter through the guide wire, positions it, and repeatedly inflates the balloon with normal saline solution and contrast medium for about 15 to 30 seconds to a pressure of 6 atmospheres. The duration of inflation and the amount of pressure used may vary, depending on the severity of the patient’s symptoms and myocardial ischemia. Several inflations with different balloon sizes may be necessary to expand the arterial wall. The expanding balloon compresses the atherosclerotic plaque against the arterial wall, expanding the arterial lumen.
Quantitative measurements of the procedure’s success are derived from pressure gradient measurements across the stenotic area of the artery. The balloon can be inflated repeatedly until the residual gradient decreases to about 20% or until the pressure gradient is less than 16 mm Hg. The surgeon then performs a repeat angiogram.
After the angioplasty procedure, intravascular stenting may be performed to maintain patency of the vessel by reducing the rate of restenosis. Various atherectomy (plaque removal) devices are also available as adjuncts to PTCA.
Complications
Although PTCA avoids many surgical risks, it can cause serious complications. The most dangerous, arterial dissection during dilatation, can lead to coronary artery rupture, cardiac tamponade, myocardial ischemia or infarction, or death. Another life-threatening complication is abrupt reclosure of the coronary artery. (See Responding to abrupt reclosure of the coronary artery.) However, the incidence of abrupt closure after PTCA has declined dramatically with the use of coronary stents.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
