Angioplasty/Stent (Coronary, Renal, Peripheral Arteries)

Angioplasty is a procedure that widens a narrow or obstructed blood vessel using a balloon catheter. It is used to treat atherosclerosis(blood vessel obstructions), and usually performed by an interventional cardiologist, a medical doctor with special training in the treatment of the heart, using invasive catheter-based procedures.

balloon-angioplasty

Angioplasty is commonly performed as a minimally-invasive (percutaneous) procedure, where a stent (small mesh tube) is inserted into the blood vessel to keep it open. A possible alternative to heart surgery, it has consistently been shown to reduce symptoms due to coronary artery disease and reduce cardiac ischemia.

The Procedure

  1. An introducer needle is inserted into the femoral artery in the leg (sometimes into the radial artery or brachial artery in the arm).
  2. A sheath introducer is placed in the opening to keep the artery open and control bleeding.
  3. A guide catheter (long, flexible, soft plastic tube) is then pushed through the sheath introducer. Dyes can be injected through the guide catheter into the coronary artery to locate and study the diseased artery using x-ray.
  4. After studying the x-ray image, the cardiologist selects the type of balloon catheter and flexible coronary guidewire that will be used.
  5. The flexible coronary guidewire with radiopaque plastic tip is then inserted into the guiding catheter and into the coronary artery.
  6. Viewing through x-ray imaging monitor, the cardiologist guides the flexible coronary guidewire through the coronary artery to the site of the blockage.
  7. When the flexible guidewire reaches the blockage, it is then pushed across the blockage.
  8. A hollow-tipped balloon catheter is then inserted, using the flexible guidewire as a pathway to the site of the blockage. At this point, the balloon is still deflated.
  9. After the balloon catheter reaches and is pushed inside the blockage, the balloon is then inflated. Inflating the balloon expands the area around it and compresses the plaque buildup (blockage). The inflated balloon also expands the artery wall.
  10. A stent (wire mesh tube) sometimes is implanted to keep the artery wall expanded. The stent initially is inserted along with the balloon catheter, expands when the balloon is inflated, and left behind in the expanded position as the balloon catheter is removed.

Coronary balloon angioplasty and stents facts

  • Coronary artery disease occurs when cholesterol plaque builds up (arteriosclerosis) in the walls of the arteries to the heart.
  • Angioplasty is successful in opening coronary arteries in well over 90% of patients.
  • Up to 30% to 40% of patients with successful coronary angioplasty will develop recurrent narrowing at the site of balloon inflation.
  • The use of newer devices such as intracoronary stents and atherectomy, as well as newer pharmacologic agents has resulted in higher success rates, reduced complications, and reduced recurrence after percutaneous coronary intervention.

What is balloon angioplasty?

Balloon angioplasty of the coronary artery, or percutaneous transluminal coronary angioplasty (PTCA), was introduced in the late 1970’s. PTCA is a non-surgical procedure that relieves narrowing and obstruction of the arteries to the muscle of the heart (coronary arteries). This allows more blood and oxygen to be delivered to the heart muscle. PTCA, is now referred to as percutaneous coronary intervention, or PCI, as this term includes the use of balloons, stents, and atherectomy devices. Percutaneous coronary intervention is accomplished with a small balloon catheter inserted into an artery in the groin or arm, and advanced to the narrowing in the coronary artery. The balloon is then inflated to enlarge the narrowing in the artery. When successful, percutaneous coronary intervention can relieve chest pain of angina, improve the prognosis of individuals with unstable angina, and minimize or stop a heart attack without having the patient undergo open heart coronary artery bypass graft (CABG) surgery.​

​Coronary Balloon Angioplasty IllustrationIn addition to the use of simple balloon angioplasty, the availability of  stents, in a wire-mesh design, have expanded the spectrum of people suitable for percutaneous coronary intervention, as well as enhanced the safety and long-term results of the procedure. Since the early 1990’s, more and more patients are treated with stents, which are delivered with a percutaneous coronary intervention balloon, but remain in the artery as a “scaffold”. This procedure has markedly reduced the numbers of patients needing emergency CABG to below 1%, and particularly with the use of the new “medicated” stents (stents coated with medications that help prevent plaque formation), has reduced the rate of recurrence of the blockage in the coronary artery (“restenosis”) to well below 10%. At present, the only patients treated with just balloon angioplasty are those with vessels less than 2mm (the smallest diameter stent), certain types of lesions involving branches of coronary arteries, those with scar tissue in old stents, or those who cannot take the blood thinner medication known asclopidogrel bisulfate (Plavix), which is taken over the long-term following the procedure.

Various “atherectomy” (plaque removal) devices were initially developed as adjuncts to percutaneous coronary intervention. These include the use of the excimer laser for photoablation of plaque, rotational atherectomy (use of a high-speed diamond-encrusted drill) for mechanical ablation of plaque, and directional atherectomy for cutting and removal of plaque. Such devices were initially thought to decrease the incidence of restenosis, but in clinical trials were shown to be of little additional benefit, and now are only used in selective cases as an adjunct to standard percutaneous coronary intervention (percutaneous artery intervention).​