Angioplasty

Angioplasty requires an access vessel, typically the femoral or radial artery or femoral vein, to permit access to the vascular system for the wires and catheters used. If no access vessel of sufficient size and quality is available, angioplasty is contraindicated. A small vessel diameter, the presence of posterior calcification, occlusion, hematoma, or an earlier placement of a bypass origin, may make access to the vascular system too difficult.

Percutaneous transluminal coronary angioplasty (PTCA) is contraindicated in patients with left main coronary artery disease, due to the risk of spasm of the left main coronary artery during the procedure.[16] Also, PTCA is not recommended if there is less than 70% stenosis of the coronary arteries, as the stenosis it is not deemed to be hemodynamically significant below this level.[16]

Balloon-tipped catheter.

Balloon inflated with stent

Diagram of a balloon catheter

Access to the vascular system is typically gained percutaneously (through the skin, without a large surgical incision). An introducer sheath is inserted into the blood vessel via the Seldinger technique.[17] Fluoroscopic guidance uses magnetic resonance or X-ray fluoroscopy and radiopaque contrast dye to guide angled wires and catheters to the region of the body to be treated in real time.[18] Tapered guidewire is chosen for small occlusion, followed by intermediate type guidewires for tortuous arteries and difficulty passing through extremely narrow channels, and stiff wires for hard, dense, and blunt occlusions.[19] To treat a narrowing in a blood vessel, a wire is passed through the stenosis in the vessel and a balloon on a catheter is passed over the wire and into the desired position.[20] The positioning is verified by fluoroscopy and the balloon is inflated using water mixed with contrast dye to 75 to 500 times normal blood pressure (6 to 20 atmospheres), with most coronary angioplasties requiring less than 10 atmospheres.[21] A stent may or may not also be placed.

At the conclusion of the procedure, the balloons, wires and catheters are removed and the vessel puncture site is treated either with direct pressure or a vascular closure device.[22]

Transradial artery access (TRA) and transfemoral artery access (TFA) are two techniques for percutaneous coronary intervention.[23] TRA is the technique of choice for management of acute coronary syndrome (ACS) as it has significantly lower incidence of bleeding and vascular complications compared with the TFA approach.[23] TRA also has a mortality benefit for high risk ACS patients and high risk bleeding patients.[23] TRA was also found to yield improved quality of life, as well as decreased healthcare costs and resources.[23]

Relative to surgery, angioplasty is a lower-risk option for the treatment of the conditions for which it is used, but there are unique and potentially dangerous risks and complications associated with angioplasty:

• Embolization, or the launching of debris into the bloodstream[24]
• Bleeding from over-inflation of a balloon catheter or the use of an inappropriately large or stiff balloon, or the presence of a calcified target vessel.[24]
• Hematoma or pseudoaneurysm formation at the access site[24]
• Radiation-induced injuries (burns) from the X-rays used[25]
• Contrast-induced renal injury[26]
• Cerebral Hyperperfusion Syndrome leading to stroke is a serious complication of carotid artery angioplasty with stenting.[27]

Angioplasty may also provide a less durable treatment for atherosclerosis and be more prone to restenosis relative to vascular bypass or coronary artery bypass grafting.[28] Drug-eluting balloon angioplasty has significantly less restenosis, late lumen loss and target lesion revascularization at both short term and midterm follow-up compared to uncoated balloon angioplasty for femoropopliteal arterial occlusive disease.[29] Although angioplasty of the femoropopliteal artery with paclitaxel-coated stents and balloons significantly reduces rates of vessel restenosis and target lesion revascularization, it was also found to have increased risk of death.[30]

After angioplasty, most patients are monitored overnight in the hospital, but if there are no complications, patients are sent home the following day.[26]

The catheter site is checked for bleeding and swelling and the heart rate and blood pressure are monitored to detect late rupture and hemorrhage.[26] Post-procedure protocol also involves monitoring urinary output, cardiac symptoms, pain and other signs of systemic problems.[26] Usually, patients receive medication that will relax them to protect the arteries against spasms. Patients are typically able to walk within two to six hours following the procedure and return to their normal routine by the following week.[31]

Angioplasty recovery consists of avoiding physical activity for several days after the procedure. Patients are advised to avoid heavy lifting and strenuous activities for a week.[32][33] Patients will need to avoid physical stress or prolonged sport activities for a maximum of two weeks after a delicate balloon angioplasty.[34]

After the initial two week recovery phase, most angioplasty patients can begin to safely return to low-level exercise. A graduated exercise program is recommended whereby patients initially perform several short bouts of exercise each day, progressively increasing to one or two longer bouts of exercise.[35] As a precaution, all structured exercise should be cleared by a cardiologist before commencing. Exercise-based rehabilitation following percutaneous coronary intervention has shown improvement in recurrent angina, total exercise time, ST-segment decline, and maximum exercise tolerance.[36]

Patients who experience swelling, bleeding or pain at the insertion site, develop fever, feel faint or weak, notice a change in temperature or color in the arm or leg that was used or have shortness of breath or chest pain should immediately seek medical advice.

Patients with stents are usually prescribed dual antiplatelet therapy (DAPT) which consists of a P2Y12 inhibitor, such as clopidogrel, which is taken at the same time as acetylsalicylic acid (aspirin).[37] Dual antiplatelet therapy (DAPT) is recommended for 1 month following bare metal stent placement, for 3 months following a second generation drug-eluting stent placement, and for 6–12 months following a first generation drug-eluting stent placement.[1] DAPT's antiplatelet properties are intended to prevent blood clots, however they also increase the risk of bleeding, so it is important to consider each patient's preferences, cardiac conditions, and bleeding risk when determining the duration of DAPT treatment.[37] Another important consideration is that concomitant use of Clopidogrel and Proton Pump Inhibitors following coronary angiography is associated with significantly higher adverse cardiovascular complications such as major adverse cardiovascular events (MACE), stent thrombosis and myocardial infarction.[38]

Angioplasty was first described by the US interventional radiologist Charles Dotter in 1964.[39] Dr. Dotter pioneered modern medicine with the invention of angioplasty and the catheter-delivered stent, which were first used to treat peripheral arterial disease. On January 16, 1964, Dotter percutaneously dilated a tight, localized stenosis of the subsartorial artery in an 82-year-old woman with painful leg ischemia and gangrene who refused leg amputation. After successful dilation of the stenosis with a guide wire and coaxial Teflon catheters, the circulation returned to her leg. The dilated artery stayed open until her death from pneumonia two and a half years later.[40] Charles Dotter is commonly known as the "Father of Interventional Radiology" and was nominated for the Nobel Prize in medicine in 1978.

The first percutaneous coronary angioplasty on an awake patient was performed in Zurich by the German cardiologist Andreas Gruentzig on September 16, 1977.[41]

Dr. Simon H. Stertzer was the first to perform coronary angioplasty in the United States on March 1, 1978, at Lenox Hill Hospital in New York. That same day, Dr. Richard K. Myler of St. Mary's Hospital in San Francisco performed the second coronary angioplasty in the United States.

The initial form of angioplasty was 'plain old balloon angioplasty' (POBA) without stenting, until the invention of bare metal stenting in the mid-1980s to prevent the early restenosis observed with POBA.[1]

Bare metal stents were found to cause in-stent restenosis as a result of neointimal hyperplasia and stent thrombosis, which led to the invention of drug-eluting stents with anti-proliferative drugs to combat in-stent restenosis.[1]

The first coronary angioplasty with a drug delivery stent system was performed by Dr. Stertzer and Dr. Luis de la Fuente, at the Instituto Argentino de Diagnóstico y Tratamiento (English: Argentina Institute of Diagnosis and Treatment[42]) in Buenos Aires, in 1999.

Ingemar Henry Lundquist invented the over-the-wire balloon catheter that is now used in the majority of angioplasty procedures in the world.[43]

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• National Heart Lung and Blood Institute, Diseases and Conditions Index