Angioplasty is a procedure used to widen arteries that have been narrowed by the buildup of plaque, a condition called atherosclerosis. Plaque blockage can occur in any artery, but angioplasty is most often performed to open the coronary arteries that supply blood to the heart. For some people, angioplasty may be an alternative to coronary bypass surgery.
In individuals with an occlusive vascular disease such as atherosclerosis, blood flow to an organ or to a distant body part such as the lower leg is reduced because of the buildup of fatty deposits and/or calcium accumulation along the walls of the artery. This narrowing may occur in any blood vessel. Once the blood vessel is widened, adequate blood flow can be restored. The vessel may narrow again over time (restenosis) and the procedure may be repeated.
Angioplasty procedures are performed in a cardiac catheterization laboratory in a hospital with facilities for proper monitoring and recovery. If the procedure is to be performed in a coronary artery, the patient's care is likely to be provided by a specially trained cardiologist, radiologist, nurses, and vascular specialists. The patient may be given anticoagulants prior to the procedure to help prevent the development of blood clots (thromboses). Administration of anticoagulants, however, may impede the sealing of the vascular entry point.
The procedure is performed using fluoroscopic guidance and contrast media, so that the physician can track the position of the catheter and the blockage. Since the decision to perform angioplasty may have been made following a diagnostic angiogram, the patient's sensitivity to iodinated contrast media is likely to be known. If patient sensitivity is unknown or if the patient's renal function is severely compromised, the procedure may require the use of an alternate contrast agent.
Angioplasties can be performed to treat coronary artery disease (narrowing of the arteries that carry blood to the heart), carotid artery disease (narrowing of arteries in the neck that carry blood to the brain), to treat peripheral artery disease (blockage of arteries in the arms and legs), and renal (kidney) vascular hypertension. There are various types of angioplasties. Their names are associated with the type of vessel entry and equipment used. For example, percutaneous transluminal angio-plasty (PTA) describes entry through the skin (percutaneous) and navigates to the area of the blockage through the same vessel or one that communicates with it (transluminal). In the case of a procedure involving the coronary arteries, the point of entry could be the femoral artery in the groin and the catheter/guide wire system is passed through the aorta to coronary arteries at the base of the aorta just outside the aortic valve.
Angioplasties can be performed using several different techniques.
Balloon angioplasty. A catheter with a deflated balloon in its tip is inserted into an artery. When the balloon reaches the blockage, it is inflated, stretching the walls of the artery and widening the vessel.
Cutting balloon. A balloon catheter with a window on one side of the catheter and small cutting blades is inserted. At the blockage, the window is positioned against the plaque and the balloon is inflated. The window presses against the blockage, and the blades are used to cut the blockage away.
Atherectomy. A hollow catheter with a window and a rotating blade is inserted. The balloon is inflated at the site of the blockage, pressing the window against the blockage. The rotating cutter is activated and the tiny pieces of plaque are captured in the hollow catheter.
Rotablation. This procedure is not performed as often as it was in the past because of the effectiveness of balloon angioplasty. A catheter with a special grinding tip is inserted and the plaque is ground away. The small pieces of plaque enter the bloodstream and are destroyed by the liver.
Angioplasty may be performed while the patient is sedated or anesthetized, depending on the vessels involved. If a percutaneous transluminal coronary angioplasty (PTCA) is to be performed, the patient will be kept awake to report discomfort and cough if required. PTCA procedures are performed in cardiac catheterization labs with sophisticated monitoring devices. If angioplasty is performed in the radiology department's angiographic suite, the patient may be sedated for the procedure and a nurse will monitor the patient' s vital signs during the procedure. If performed by a vascular surgeon, the angioplasty procedure will be performed in an operating room or specially designed vascular procedure suite.
At the start of the procedure, the site of the introduction of the angioplasty equipment is prepared as a sterile surgical site. Once the guide wire is introduced, small injections of contrast media are used to visualize the path through the vessel using x-ray technology.
When the blockage is reached, the physician inflates the balloon or performs other angioplasty procedures. In some cases, a stent (a mesh of wire that resembles a Chinese finger puzzle) may be inserted to keep the vessel open. Some stents, called drug-eluting stents, contain a drug that is slowly released into the bloodstream to help to prevent the artery from narrowing again (restenosis).
Widening of the artery and placement of a stent are verified using fluoroscopy and contrast media to produce an angiogram or by using intravascular ultrasound or both. All equipment is withdrawn from the vessel and the puncture site is repaired.
During the procedure, there is a danger of puncturing the vessel with the guide wire. This is a very small risk. Patients must be monitored for bleeding at the puncture site. There is also a small risk of heart attack, the formation of blood clots that block the artery (emboli), and, although unlikely, death. Hospitalization will vary in length depending on the patient' s overall condition, any complications, and the availability of home care.
Angioplasty is not appropriate for some individuals. Many seniors have additional health problems or are taking medications that increase the risk of complications. Also, seniors are often slower to recover from the procedure than younger individuals.
See also Atherosclerosis; Blood pressure; Cholesterol-reducing drugs; Coronary artery disease; Heart disease.
相关 Credo 文章
Definition Angioplasty is a term describing a procedure used to widen vessels narrowed by stenoses or occlusions. There are various types of thes
What Is It? Angioplasty is a procedure in which a tiny device is inserted into narrowed blood vessels that supply blood to the heart. This devic
a cardiovascular procedure that is performed to widen the lumen of a partially or fully occluded blood vessel (as the femoral or coronary artery) na