Angioplasty
Angioplasty
Definition
Angioplasty is a term describing a procedure used to widen vessels narrowed by stenoses or occlusions. There are various types of these procedures and their names are associated with the type of vessel entry and equipment used. For example, percutaneous transluminal angioplasty (PTA) describes entry through the skin (percutaneous) and navigates to the area of the vessel of interest 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/guidewire system is passed through the aorta to the heart and the origin of the coronary arteries at the base of the aorta just outside the aortic valve.
Purpose
In individuals with an occulsive vascular disease such as atherosclerosis, blood flow is impaired to an organ (such as the heart) or to a distal body part (such as the lower leg) by the narrowing of the vessel's lumen due to fatty deposits or calcium accumulation. This narrowing may occur in any vessel but may occur anywhere. Once the vessel has been widened, adequate blood flow is returned. The vessel may narrow again over time at the same location and the procedure could be repeated.
Precautions
Angioplasty procedures are performed on hospital inpatients in 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 specially trained physicians, nurses, and vascular specialists. Typically, patients are given anticoagulants prior to the procedure to assist in the prevention of thromboses (blood clots ). Administration of anticoagulants, however, may impede the sealing of the vascular entry point. The procedure will be performed using fluoroscopic guidance and contrast media. 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 known. The procedure may then require the use of non-ionic contrast agents.
Description
Angioplasty was originally performed by dilating the vessel with the introduction of larger and larger stiff catheters through the narrowed space. Complications of this procedure caused researchers to develop means of widening the vessel using a minimally sized device. Today, catheters contain balloons that are inflated to widen the vessel and stents to provide structural support for the vessel. Lasers may be used to assist in the break up of the fat or calcium plaque. Catheters may also be equipped with spinning wires or drill tips to clean out the plaque.
KEY TERMS
plaque— In atherosclerosis, a swollen area in the lining of an artery formed by fatty deposits.
cardiac catheterization— A procedure to pass a catheter to the heart and its vessels for the purpose of diagnosing coronary artery disease, assessing injury or disease of the aorta, or evaluating cardiac function.
EKG— Electrocardiogram, used to study and record the electrical activity of the heart.
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 on 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.
The site of the introduction of the angioplasty equipment is prepared as a sterile surgical site. Although many procedures are performed by puncturing the vessel through skin, many procedures are also performed by surgically exposing the site of entry. Direct view of the vessel's puncture site aids in monitoring damage to the vessel or excessive bleeding at the site. Once the vessel is punctured and the guidewire is introduced, fluoroscopy is used to monitor small injections of contrast media used to visualize the path through the vessel. If the fluoroscopy system has a feature called 'roadmap', the amount of contrast media injected will be greater in order to define the full route the guidewire will take. The fluoroscopy system will then superimpose subsequent images over the roadmap while the vessel is traversed, that is, the physician moves the guidewire along the map to the destination.
Having reached the area of stenosis, the physician will inflate the balloon on the catheter that has been passed along the guidewire. Balloons are inflated in size and duration depending on the size and location of the vessel. In some cases, the use of a stent (a mesh of wire that resembles a Chinese finger puzzle) may also be used. The vessel may be widened before, during, or after the deployment of the stent. Procedures for deploying stents are dependent on the type of stent used. In cases where the vessel is tortuous or at intersections of vessels, the use of a graph may be necessary to provide structural strength to the vessel. Stents, graphs, and balloon dilation may all be used together or separately.
The procedure is 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 repaired.
Risks
During the procedure there is a danger of puncturing the vessel with the guidewire. This is a very small risk. Patients must be monitored for hematoma or hemorrhage at the puncture site. There is also a small risk of heart attack, emboli, and although unlikely death. Hospitalization will vary in length by the patient's overall condition, any complications, and availability of home care.
Resources
PERIODICALS
"The angioplasty correct follow up strategy after stent implantation." Heart 84, no. 4 (April, 2001): 363.
Carnall, Douglas. "Angioplasty." The Western Journal of Medicine 173, no. 3 (September 2000): 201.
"New Imaging Technique Could Improve Outcome of Popular Heart Procedure." Heart Disease Weekly May 13, 2001: 3.
"Success clearing clogged arteries." Science News 159, no. 5 (February 3, 2001): 72.
OTHER
"Cardiovascular System" Miami Heart Research Institute 2001. [cited July 5, 2001]. 〈http://www.miamiheartresearch.org/Learning Center/YourCardiovascular…/Cardiovascular.htm〉.
"Coronary angioplasty: Opening clogged arteries" MayoClinic.com, Condition Centers, Treatments and Tests. 2000. [cited July 5, 2001]. 〈http://www.mayoclinic.com〉.
"Heart American Heart Association online. 2000. [cited July 5, 2001]. 〈http://www.americanheart.org/Heart_and_Stroke_A_Z_Guide/angiol.html〉.
"STS Patient Information: What to Expect after your Heart Surgery." Society of Thoracic Surgeons online. 2000. [cited July 5, 2001]. 〈http://www.sts.org/doc/3563〉.
"When you need to have Angioplast: A patient guide" Heart Information Network. 2000. [cited July 5, 2001]. 〈http://www.heartinfo.org/news97/gdangio111897.htm〉.
Angioplasty
Angioplasty
Definition
Purpose
Description
Risks
Alternatives
Health care team roles
Definition
Angioplasty is a procedure used to widen narrowed or partially blocked, or occluded, blood vessels. There are various types of angioplasty. The specific names of these procedures are derived from the type of equipment used and the path of entry to the blood vessel. For example, percutaneous transluminal angioplasty (PTA) means that the vessel is entered through the skin (percutaneous) and that the catheter is moved into the blood vessel of interest through the same vessel or one that communicates with it (transluminal). In the case of an angioplasty involving the coronary arteries, the point of entry might be the femoral artery in the groin, with the catheter/guide-wire system passed through the aorta to the heart and the origin of the coronary arteries at the base of the aorta just outside the aortic valve.
Purpose
An angioplasty is done to reopen a partially blocked blood vessel so that blood can flow through it again at a normal rate. In patients with an occlusive vascular disease such as atherosclerosis, the flow of blood to other organs or remote parts of the body is limited by the narrowing (stenosis) of the vessel’s lumen due to fatty deposits or patches known as plaque. Once the vessel has been widened, an adequate blood flow is restored, but the vessel may narrow again over time (restenosis) at the same location and the procedure may need to be repeated.
Description
Angioplasties were originally performed by dilating the blood vessel with the introduction of larger and larger stiff catheters through the narrowed space. The complications that resulted from this approach led researchers to develop other ways to open the vessel with smaller devices. An alternative approach was developed in which the catheters used to perform angioplasties contain balloons that are gradually inflated to widen the vessel. Stents, which are thin collapsed tubes made of wire mesh sometimes coated with drugs that help prevent the blood vessel from re-closing can be inserted to provide structural support for the vessel. Lasers may be used to help break up the plaque or fat deposits lining the vessel. Some catheters are equipped with spinning wires or drill tips to clean out the plaque.
Angioplasty may be performed while the patient is either sedated or anesthetized, depending on which vessels are involved. If a percutaneous transluminal coronary angioplasty (PTCA) is to be performed, the patient is sedated so that he or she can report discomfort and cough if asked to do so. PTCA procedures are performed in cardiac catheterization laboratories with sophisticated monitoring devices. If angioplasty is performed in the radiology department’s angiographic suite, the patient may be sedated for the procedure while a nurse monitors the patient’s vital signs. Angioplasties performed by vascular surgeons are done in an operating room or specially designed vascular procedure suite.
Typically, patients are given anticoagulant, or blood thinning, medications before the procedure to assist in the prevention of thromboses (blood clots), even though these drugs may slow down the sealing of the entry point of the catheter into the vein. Patients may also be given calcium channel blockers and nitrates to reduce the risk of vascular spasm. The angioplasty is performed using fluoroscopic guidance and contrast media. Since the decision to perform angioplasty may have been made following a diagnostic angiogram, the patient’s sensitivity to contrast media containing iodine is likely to be known. The procedure may then require the use of an alternative contrast agent.
The patient’s skin is cleansed with an antiseptic solution at the site where the surgeon will insert the catheter and other equipment, and the area is protected with a sterile drape. Although many angioplasties are performed by puncturing the vessel through the skin, others are done by surgically exposing the site of entry. Direct view of the vessel’s puncture site aids in monitoring damage to the vessel or excessive bleeding at the site. After the vessel has been punctured and the guide-wire introduced, a fluoroscope is used to monitor the small amounts of contrast media that have been injected. This technique allows the surgeon to see the guidewire’s movement through the vessel. If the fluoroscope has a feature called “roadmap,” the amount of contrast media injected is greater in order to define the full route the guidewire will take. The fluoroscopy system then superimposes subsequent images over the roadmap while the physician moves the guidewire along the mapped route to the destination.
When the surgeon reaches the location of the stenosis, he or she inflates the balloon on the catheter that has been passed along the guidewire. The size of the balloon and the duration of its inflation depend on the size and location of the vessel. In some cases, the surgeon may also use a stent, which is opened or expanded inside the blood vessel after it has been
KEY TERMS
Anticoagulant— A type of medication given to prevent the formation of blood clots. Anticoagulants are also known as blood thinners.
Arterosclerosis— A chronic condition characterized by thickening and hardening of the arteries and the build-up of plaque on the arterial walls. Arterosclerosis can slow or impair blood circulation.
Calcium channel blocker— A drug that lowers blood pressure by regulating calcium-related electrical activity in the heart.
Cardiac catheterization— A procedure to pass a catheter to the heart and its vessels for the purpose of diagnosing coronary artery disease, assessing injury or disease of the aorta, or evaluating cardiac function.
Contrast medium— A substance that is swallowed or injected into the body to create clearer images in radiographic studies of internal structures.
Electrocardiogram (EKG)— A graphic tracing of the electrical activity of the heart. By looking at the graph, some heart abnormalities can be diagnosed/
Embolus (plural emboli)— A gas or air bubble, bit of tissue, blood clot, or foreign object that circulates in the bloodstream until it lodges in a vessel. A large embolus can narrow or block the vessel, which leads to decreased blood flow in the organ supplied by that vessel.
Fluoroscopy— A radiologic technique that creates X-ray images of internal body structures for immediate projection on a fluorescent screen.
Hematoma— A localized collection of blood in an organ or tissue due to broken blood vessels.
Lumen— The cavity or channel inside a blood vessel or tube-shaped organ.
Occlusion— An obstruction or blockage in a blood vessel.
Patency— Being widely open. A blood vessel that has been widened or reopened is said to be patent.
Plaque— In atherosclerosis, a swollen area in the lining of an artery formed by fatty deposits.
Stenosis (plural, stenoses)— The narrowing or constriction of an opening or passageway in the body.
Stent— A thin rod-like or tube-like device made of wire mesh, inserted into a vein or artery to keep the vessel open.
guided to the proper location. The blood vessel may be widened before, during, or after the stent has been opened up. In cases where the vessel is tortuous (twisted) or at intersections of vessels, a graft may be necessary to strengthen the walls of the blood vessel. Stents, grafts, and balloon dilation may all be used together or separately. Sometimes radiation is used when a stent is placed.
After the surgeon has widened the blood vessel, he or she verifies its patency by using fluoroscopy and contrast media to produce an angiogram, by using intravascular ultrasound, or by using both techniques. After the imaging studies have been completed, the surgeon removes the equipment from the blood vessel and closes the puncture site.
Risks
There is a danger of puncturing the vessel with the guidewire during an angioplasty, although the risk is very small. Patients must be monitored for hematoma or hemorrhage at the puncture site. There is also a small risk of heart attack, stroke, and, although unlikely, death—all related to vessel spasm (transient vessel narrowing from irritation by the catheter), or from emboli (as plaque can be dislodged by the catheter or and travel to the heart or brain). Abrupt closure of the coronary artery occurs in about 4% of patients.
Recurrence of stenosis, known as restenosis, is an additional potential complication. The risk of recurrence is highest in the first six months after angioplasty, with rates as high as 35% reported in some studies.
The length of the patient’s hospital stay following an angioplasty depends on his or her overall health, the occurrence of complications, and the availability of home care.
Alternatives
For some patients, thrombolytic therapy (treatment with drugs that dissolve blood clots) coupled with lifestyle changes is an alternative to angioplasty. Many medical centers, in fact, restrict the use of angioplasty to patients who cannot be treated with thrombolytic therapy.
Health care team roles
Physicians often have specially trained assistants for vascular procedures. These assistants may be nurses, surgical technicians, or X-ray specialists. Cardiac catheterization laboratories will include someone specially trained in monitoring EKG equipment and vital signs. Either a nurse, nurse anesthetist, or anesthesiologist will administer sedation or anesthesia for the procedure.
Resources
BOOKS
Beers, M. H., R. S. Porter, T. V. Jones, J. L. Kaplan, and M. Berkwits, eds. “Diagnostic Cardiovascular Procedures: Invasive Procedures.” In The Merck Manual of Diagnosis and Therapy, 18th ed. Whitehouse Station, NJ: Merck Research Laboratories, 2006.
Ohman, Magnus. So You’re Having a Heart Cath and Angioplasty. Hoboken, NJ: Wiley, 2003.
OTHER
“Angioplasty.” MedlinePlus. February 7, 2008. http://www.nlm.nih.gov/medlineplus/angioplasty.html (February 11, 2008).
“Balloon Angioplasty and Stents.” Texas Heart Institute. July 2007. http://www.texasheartinstitute.org/HIC/Topics/Proced/angioplasty.cfm (February 11, 2008).
“Coronary Angioplasty and Stenting: Opening Clogged Heart Arteries.” Mayo Clinic. December 20, 2006. http://www.mayoclinic.com/health/angioplasty/HQ00485 (February 11, 2008).
ORGANIZATIONS
American Heart Association, 7272 Greenville Avenue, Dallas, TX, 75231, (800) 242-8721, http://www.americanheart.org.
National Heart, Lung, and Blood Institute Information Center, P.O. Box 30105, Bethesda, MD, 20824-0105, (301) 592-8573, (240) 629-3246, http://www.nhlbi.nih.gov.
Elaine R. Proseus, M.B.A./T.M., B.S.R.T., R.T.(R)
Lee A. Shratter, M.D.
Tish Davidson, A. M.
Angioplasty
Angioplasty
Definition
Angioplasty is a term describing a procedure used to widen vessels narrowed by stenoses or occlusions. There are various types of these procedures and their names are associated with the type of vessel entry and equipment used. For example, percutaneous transluminal angioplasty (PTA) describes entry through the skin (percutaneous) and navigates to the area of the vessel of interest 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/guidewire system is passed through the aorta to the heart and the origin of the coronary arteries at the base of the aorta just outside the aortic valve.
Purpose
In individuals with an occulsive vascular disease such as atherosclerosis, blood flow is impaired to an organ (such as the heart) or to a distal (away from the central portion of the body) body part (such as the lower leg) by the narrowing of the vessel's lumen due to fatty deposits or calcium accumulation. This narrowing may occur in any vessel but may occur anywhere. Once the vessel has been widened, adequate blood flow is restored. The vessel may narrow again over time at the same location and the procedure may then be repeated.
Precautions
Angioplasty procedures are performed on hospital inpatients in 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 specially trained physicians, nurses, and vascular specialists. Typically, patients are given anticoagulants prior to the procedure to assist in the prevention of thromboses (blood clots). Administration of anticoagulants, however, may impede the sealing of the vascular entry point. The procedure is performed using fluoroscopic guidance and contrast media. 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 known. The procedure may then require the use of non-ionic contrast agents.
Description
Angioplasty was originally performed by dilating the vessel with the introduction of larger and larger stiff catheters through the narrowed space. Complications of this procedure caused researchers to develop means of widening the vessel using a minimally sized device. Today, catheters contain balloons that are inflated to widen the vessel and stents (devises comprised of a mesh of wire that resembles a "Chinese finger puzzle") to provide structural support for the vessel. Lasers may be used to assist in the break up of the fat or calcium plaque. Catheters may also be equipped with spinning wires or drill tips to clean out the plaque.
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 is kept awake to report on discomfort and to 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 monitors the patient's vital signs during the procedure. If performed by a vascular surgeon, the angioplasty procedure is performed in an operating room or specially designed vascular procedure suite.
The site of the introduction of the angioplasty equipment is prepared as a sterile surgical site. Although many procedures are performed by puncturing the vessel through skin, many procedures are also performed by surgically exposing the site of entry. Direct view of the vessel's puncture site aids in monitoring damage to the vessel or excessive bleeding at the site. Once the vessel is punctured and the guidewire is introduced, fluoroscopy is used to monitor small injections of contrast media used to visualize the path through the vessel. If the fluoroscopy system has a feature called "roadmap," the amount of contrast media injected is greater in order to define the full route the guidewire will take. The fluoroscopy system then superimposes subsequent images over the roadmap while the vessel is traversed, that is, the physician moves the guidewire along the map to the destination.
Having reached the area of stenosis, the physician inflates the balloon on the catheter that has been passed along the guidewire. Balloons are inflated in size and duration depending on the size and location of the vessel. In some cases, a stent may also be used. The vessel may be widened before, during, or after the deployment of the stent. Procedures for deploying stents are dependent on the type of stent used. In cases where the vessel is tortuous (twisted) or at intersections of vessels, the use of a graph may be necessary to provide structural strength to the vessel. Stents, graphs, and balloon dilation may all be used together or separately. Sometimes radiation is used with stents.
The procedure is 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.
Complications
During the procedure there is a danger of puncturing the vessel with the guidewire. This is a very small risk. Patients must be monitored for hematoma or hemorrhage at the puncture site. There is also a small risk of heart attack, emboli, and, although unlikely, death. Hospitalization varies in length with the patient's overall condition, any complications, and the availability of home care.
Health care team roles
Physicians often have specially trained assistants for vascular procedures. These assistants may be nurses, surgical techs, or radiographers. In cardiac catheterization labs, the team also includes a member specially trained in monitoring EKG equipment and vital signs. Angioplasty is a fluoroscopy-guided procedure so a radiographer trained in vascular imaging is also required. Either a nurse, nurse anesthetist, or anesthesiologist will administer sedation or anesthesia for the procedure.
KEY TERMS
Cardiac catheterization— A procedure to pass a catheter to the heart and its vessels for the purpose of diagnosing coronary artery disease, assessing injury or disease of the aorta, or evaluating cardiac function.
Contrast medium— A substance injected into the body to facilitate the radiographic imaging of internal structures.
EKG— Electrocardiogram, used to study and record the electrical activity of the heart.
Embolus— A gas or air bubble, bit of tissue, blood clot, or foreign object that circulates in the bloodstream until it lodges in a vessel.
Fluoroscopy— A radiologic technique that creates x-ray images of internal body structures for immediate projection on a fluorescent screen.
Hematoma— A collection of blood trapped in the tissues of the skin or in an organ.
Occlusion— A blockage in a vessel.
Plaque— In atherosclerosis, a swollen area in the lining of an artery formed by fatty deposits.
Stenosis— Narrowing or constriction of an opening or passageway.
Resources
BOOKS
Larson, Jeffrey P. "Angioplasty." Gale Encyclopedia of Medicine. Third Edition Detroit: Gale Group, 2006.
Schneider, Peter A. Endovascular Skills: Guidewires, Catheters, Arteriography, Balloon Angioplasty, Stents. St. Louis, MO: Quality Medical Publishing, Inc., 1998.
Wojtowycz, Myron. Handbook of Interventional Radiology and Angiography. 2nd ed. Chicago, IL: Mosby-Year Book, 1995.
PERIODICALS
"The 'Angioplastically Correct' Follow Up Strategy After Stent Implantation." Heart 85 (April, 2001): 363.
Carnall, Douglas. "Angioplasty." The Western Journal of Medicine 173 (September 2000): 201.
"New Imaging Technique Could Improve Outcome of Popular Heart Procedure." Heart Disease Weekly (May 13, 2001):3.
"Success Clearing Clogged Arteries." Science News 159 (February 3, 2001): 72.
OTHER
"Cardiovascular System." Miami Heart Research Institute. 2001. 〈http://www.miamiheartresearch.org/LearningCenter/YourCardiovascular…/Cardiovascular.htm〉 (July 5, 2001).
"Coronary Angioplasty: Opening Clogged Arteries." MayoClinic.com, Condition Centers, Treatments and Tests. 2000. 〈http://www.mayoclinic.com〉 (July 5, 2001).
"Heart & Stroke Guide: Laser Angioplasty." American Heart Association online. 2000. 〈http://www.americanheart.org/Heart_and_Stroke_A_Z_Guide/angiol.html〉 (July 5, 2001).
"STS Patient Information: What to Expect After Your Heart Surgery." Society of Thoracic Surgeons online. 2000. 〈http://www.sts.org/doc/3563〉 (July 5, 2001).
"When You Need to Have Angioplasty: A Patient Guide." Heart Information Network. 2000. 〈http://www.heartinfo.org/news97/gdangio111897.htm〉 (July 5, 2001).
Angioplasty
Angioplasty
Definition
Angioplasty is a term describing a procedure used to widen vessels narrowed by stenoses or occlusions. There are various types of angioplasty. The specific names of these procedures are derived from the type of equipment used and the path of entry to the blood vessel. For example, percutaneous transluminal angioplasty (PTA) means that the vessel is entered through the skin (percutaneous) and that the catheter is moved into the blood vessel of interest through the same vessel or one that communicates with it (transluminal). In the case of an angioplasty involving the coronary arteries, the point of entry might be the femoral artery in the groin, with the catheter/guidewire system passed through the aorta to the heart and the origin of the coronary arteries at the base of the aorta just outside the aortic valve.
Purpose
An angioplasty is done to reopen a partially blocked blood vessel so that blood can flow through it again at a normal rate. In patients with an occlusive vascular disease such as atherosclerosis, the flow of blood to other organs or remote parts of the body is limited by the narrowing of the vessel's lumen due to fatty deposits or patches known as plaque. Once the vessel has been widened, an adequate blood flow is restored. The vessel may narrow again over time at the same location, however, and the procedure may need to be repeated.
For some patients, thrombolytic therapy (treatment with drugs that dissolve blood clots) is an alternative to angioplasty. Many medical centers, in fact, restrict the use of angioplasty to patients who cannot be treated with thrombolytic therapy.
Description
Angioplasties were originally performed by dilating the blood vessel with the introduction of larger and larger stiff catheters through the narrowed space. The complications that resulted from this approach led researchers to develop ways to open the vessel with smaller devices. As of 2003, the catheters used to perform angioplasties contain balloons that are inflated to widen the vessel, and stents (thin collapsed tubes made of wire mesh) to provide structural support for the vessel. Lasers may be used to help break up the plaque or fat deposits. Some catheters are equipped with spinning wires or drill tips to clean out the plaque.
Angioplasty may be performed while the patient is sedated or anesthetized, depending on which vessels are involved. If a percutaneous transluminal coronary angioplasty (PTCA) is to be performed, the patient is sedated so that he or she can report discomfort and cough if asked to do so. PTCA procedures are performed in cardiac catheterization laboratories with sophisticated monitoring devices. If angioplasty is performed in the radiology department's angiographic suite, the patient may be sedated for the procedure while a nurse monitors the patient's vital signs . Angioplasties performed by vascular surgeons are done in an operating room or specially designed vascular procedure suite.
Typically, patients are given anticoagulant (blood thinning) medications prior to the procedure to assist in the prevention of thromboses (blood clots), even though these drugs may slow down the sealing of the entry point into the vein. Patients may also be given calcium blockers and nitrates to reduce the risk of vascular spasm. The procedure is performed using fluoroscopic guidance and contrast media. 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. The procedure may then require the use of non-ionic contrast agents.
The patient's skin is cleansed with an antiseptic solution at the site where the surgeon will insert the catheter and other equipment, and the area is protected with a sterile drape. Although many angioplasties are performed by puncturing the vessel through the skin, others are done by surgically exposing the site of entry. Direct view of the vessel's puncture site aids in monitoring damage to the vessel or excessive bleeding at the site. After the vessel has been punctured and the guidewire introduced, a fluoroscope is used to monitor the small amounts of contrast media that have been injected. This technique allows the surgeon to see the guidewire's movement through the vessel. If the fluoroscope has a feature called "roadmap," the amount of contrast media injected is greater in order to define the full route the guidewire will take. The fluoroscopy system then superimposes subsequent images over the roadmap while the physician moves the guidewire along the roadmap to the destination.
When the surgeon reaches the location of the stenosis, he or she inflates the balloon on the catheter that has been passed along the guidewire. The size of the balloon and the duration of its inflation depend on the size and location of the vessel. In some cases, the surgeon may also use a stent, which is opened or expanded inside the blood vessel after it has been guided to the proper location. The blood vessel may be widened before, during, or after the stent has been opened up. In cases where the vessel is tortuous (twisted) or at intersections of vessels, a graft may be necessary to strengthen the walls of the blood vessel. Stents, grafts, and balloon dilation may all be used together or separately. Sometimes radiation is used when a stent is placed.
After the surgeon has widened the blood vessel, he or she verifies its patency by using fluoroscopy and contrast media to produce an angiogram, by using intravascular ultrasound, or by using both techniques. After the imaging studies have been completed, the surgeon removes the equipment from the blood vessel and closes the puncture site.
Risks
There is a danger of puncturing the vessel with the guidewire during an angioplasty, although the risk is very small. Patients must be monitored for hematoma or hemorrhage at the puncture site. There is also a small risk of heart attack, stroke, and, although unlikely, death—all related to vessel spasm (transient vessel narrowing from irritation by the catheter), or from emboli (as plaque can be dislodged by the catheter or and travel to the heart or brain). Abrupt closure of the coronary artery occurs in about 4% of patients.
Recurrence of stenosis is an additional potential complication. The risk of recurrence is highest in the first six months after angioplasty, with rates as high as 35% reported in some studies.
The length of the patient's hospital stay following an angioplasty depends on his or her overall condition, the occurrence of complications, and the availability of home care .
Health care team roles
Physicians often have specially trained assistants for vascular procedures. These assistants may be nurses, surgical technicians, or x ray specialists. Cardiac catheterization laboratories will include someone specially trained in monitoring EKG equipment and vital signs. Either a nurse, nurse anesthetist, or anesthesiologist will administer sedation or anesthesia for the procedure.
Resources
books
"Diagnostic Cardiovascular Procedures: Invasive Procedures." Section 16, Chapter 198 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, MD, and Robert Berkow, MD. Whitehouse Station, NJ: Merck Research Laboratories, 1999.
Schneider, Peter A. Endovascular Skills: Guidewires, Catheters, Arteriography, Balloon Angioplasty, Stents. St. Louis, MO: Quality Medical Publishing, Inc., 1998.
periodicals
Carnall, Douglas. "Angioplasty." Western Journal of Medicine 173 (September 2000): 201.
"New Imaging Technique Could Improve Outcome of Popular Heart Procedure." Heart Disease Weekly (May 13, 2001): 3.
Schiele, F. "The 'Angioplastically Correct' Follow Up Strategy After Stent Implantation." Heart 85 (April, 2001): 363-364.
"Success Clearing Clogged Arteries." Science News 159 (February 3, 2001): 72.
organizations
American Heart Association (AHA), National Center. 7272 Greenville Avenue, Dallas, TX 75231. (800) 242-8721. <www.americanheart.org>.
other
American Heart Association. Heart & Stroke Guide: Laser Angioplasty. [cited July 5, 2001]. <www.americanheart.org/Heart_and_Stroke_A_Z_Guide/angiol.html>.
MayoClinic.com. Coronary Angioplasty: Opening Clogged Arteries. [cited July 5, 2001]. <www.mayoclinic.com>.
Miami Heart Research Institute. Cardiovascular System, 2001. [cited July 5, 2001]. <www.miamiheartresearch.org/LearningCenter/YourCardiovascular../Cardiovascular.htm>.
Elaine R. Proseus MBA/TM, BSRT, RT(R) Lee A. Shratter, M.D.
Angioplasty
Angioplasty
Definition
Angioplasty is a term describing a procedure used to widen vessels narrowed by stenoses or occlusions.
There are various types of these procedures and their names are associated with the type of vessel entry and equipment used. For example, percutaneous transluminal angioplasty (PTA) describes entry through the skin (percutaneous) and navigates to the area of the vessel of interest 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/guidewire system is passed through the aorta to the heart and the origin of the coronary arteries at the base of the aorta just outside the aortic valve.
Purpose
In individuals with an occulsive vascular disease such as atherosclerosis , blood flow is impaired to an organ (such as the heart) or to a distal body part (such as the lower leg) by the narrowing of the vessel's lumen due to fatty deposits or calcium accumulation. This narrowing may occur in any vessel but may occur anywhere. Once the vessel has been widened, adequate blood flow is returned. The vessel may narrow again over time at the same location and the procedure could be repeated.
Precautions
Angioplasty procedures are performed on hospital inpatients in 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 specially trained physicians, nurses, and vascular specialists. Typically, patients are given anticoagulants prior to the procedure to assist in the prevention of thromboses (blood clots) . Administration of anticoagulants, however, may impede the sealing of the vascular entry point. The procedure will be performed using fluoroscopic guidance and contrast media. 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 known. The procedure may then require the use of non-ionic contrast agents.
Description
Angioplasty was originally performed by dilating the vessel with the introduction of larger and larger stiff catheters through the narrowed space. Complications of this procedure caused researchers to develop means of widening the vessel using a minimally sized device. Today, catheters contain balloons that are inflated to widen the vessel and stents to provide structural support for the vessel. Lasers may be used to assist in the break up of the fat or calcium plaque. Catheters may also be equipped with spinning wires or drill tips to clean out the plaque.
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 on 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.
KEY TERMS
Cardiac catheterization —A procedure to pass a catheter to the heart and its vessels for the purpose of diagnosing coronary artery disease, assessing injury or disease of the aorta, or evaluating cardiac function.
EKG —Electrocardiogram, used to study and record the electrical activity of the heart.
Plaque —In atherosclerosis, a swollen area in the lining of an artery formed by fatty deposits.
The site of the introduction of the angioplasty equipment is prepared as a sterile surgical site. Although many procedures are performed by puncturing the vessel through skin, many procedures are also performed by surgically exposing the site of entry. Direct view of the vessel's puncture site aids in monitoring damage to the vessel or excessive bleeding at the site. Once the vessel is punctured and the guidewire is introduced, fluoroscopy is used to monitor small injections of contrast media used to visualize the path through the vessel. If the fluoroscopy system has a feature called “roadmap”, the amount of contrast media injected will be greater in order to define the full route the guidewire will take. The fluoroscopy system will then superimpose subsequent images over the roadmap while the vessel is traversed, that is, the physician moves the guidewire along the map to the destination.
Having reached the area of stenosis, the physician will inflate the balloon on the catheter that has been passed along the guidewire. Balloons are inflated in size and duration depending on the size and location of the vessel. In some cases, the use of a stent (a mesh of wire that resembles a Chinese finger puzzle) may also be used. The vesselmay be widened before, during, or after the deployment of the stent. Procedures for deploying stents are dependent on the type of stent used. In cases where the vessel is tortuous or at intersections of vessels, the use of a graph may be necessary to provide structural strength to the vessel. Stents, graphs, and balloon dilation may all be used together or separately.
The procedure is 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 repaired.
Risks
During the procedure there is a danger of puncturing the vessel with the guidewire. This is a very small risk. Patients must be monitored for hematoma or hemorrhage at the puncture site. There is also a small risk of heart attack , emboli, and although unlikely death . Hospitalization will vary in length by the patient's overall condition, any complications, and availability of home care .
Resources
PERIODICALS
“The angioplasty correct follow up strategy after stent implantation.” Heart 84, no. 4 (April, 2001): 363.
Carnall, Douglas. “Angioplasty.” The Western Journal of Medicine 173, no. 3 (September 2000): 201.
“New Imaging Technique Could Improve Outcome of Popular Heart Procedure.” Heart Disease Weekly (May 13, 2001): 3.
“Success clearing clogged arteries.” Science News 159, no. 5 (February 3, 2001): 72.
Elaine R. Proseus MBA/TM, BSRT, RT(R)