Intravascular ultrasound (IVUS) is a special technique used along with percutaneous coronary intervention for complex coronary artery disease. This technology overcomes a number of limitations of nuclear imaging of blood vessels by taking pictures within the blood vessels and creating a cross-section with a 360-degree perspective to form a three-dimensional structure.
IVUS is used as an adjunct in the diagnosis and treatment of both arteries and veins. In the veins, IVUS is most often used for acute and chronic blood clots, especially if narrowing of the veins is thought to be the culprit. The endovascular ultrasound can help find areas of narrowing or occlusion deep in the body and also help measure the veins for appropriate sizing of stents to keep the vessel open. In the arteries, IVUS is performed to see peripheral arteries of the legs and coronary arteries, although it may be used in any artery in the body. IVUS is often used in conjunction with catheter angiography to help diagnose peripheral artery disease which is not well seen on the angiogram and to plan the size of stents which may need to be placed to keep the artery open. IVUS can be used to visualize the coronary arteries in conjunction with or to help plan for catheter angiography or angioplasty and vascular stenting. Unlike angiography, IVUS can show the entire artery wall and reveal more information about plaque buildup (atherosclerosis), which is associated with an increased risk of heart attack. Information from IVUS often affects treatment decisions, such as the sizing of a stent and where it should be placed. It is often used after angioplasty and vascular stenting to confirm the stent has been placed correctly and that the procedure has addressed the problem. IVUS is also used to assess abdominal aortic aneurysm before, during and after interventions to repair the vessel.
-To examine abnormalities or the artery and the structures of the narrowed artery. Intravascular ultrasound allows the doctor to assess the amount of plaque, determine the location for the stent as well as the size required, and determine complications of the procedure. Intravascular ultrasound also plays an important role in determining why a stent fails, such as excessive blockage in the stent or narrowing of the stent. This allows for further treatment planning.
-irregular heart rhythms (arrhythmia)
-a blood clot
-an allergic reaction to the medications used during the procedure
-in very rare cases, a heart attack, stroke, or blood clot in the lung
Typically, IVUS is an outpatient service, but if you have it with another procedure, you may need to be an inpatient. Your doctor will discuss this with you so that you can prepare. The first stage will be getting you comfortable and sedated. You may wear loose, comfortable clothing, but it is more likely that you will don a surgical gown for the IVUS. Some patients need a general anesthetic, but most do not. You will be attached to standard monitors - heart rate, pulse, blood oxygen, and blood pressure, for the whole of the procedure. You will receive a sedative through an IV (intravenous) line inserted into a vein in your arm or the back of your hand. This insertion may pinch a little, but the discomfort is mild. The groin area is usually the chosen insertion site for the catheter. After cleaning and sterilizing the site, a local anesthetic applied. You may experience a stinging or burning sensation until the area becomes numb. Again, the feeling is uncomfortable rather than painful. Following a small cut, a sheath is put into the incision to make it easy to slide the catheter into the vein (or artery). The probe or transducer at the end of the catheter navigates to the target area (possibly more than one) and the soundwaves emitted are converted into images on the computer screen. You won't feel the catheter moving around, and the sound waves are non-ionizing. You won't feel them. When the procedure is over, the doctor removes the catheter and sheath and applies pressure to seal up the incision. The doctor may use a closure device, but there are no stitches as it is a small cut. An applied surgical dressing covers up the incision, and a nurse or doctor will discuss aftercare. After removing the IV line and unhooking you from the monitors, you will need to remain flat for a few hours. You are likely to be still sleepy from sedation, and your doctor will want to be sure that the insertion site has closed and is not bleeding.
This procedure requires little or no special preparation. However, since it is often used in conjunction with another procedure, you should ask your doctor about how to prepare and whether you will be admitted to the hospital for observation. If you are to be sedated, you may be asked not to eat or drink anything for up to eight hours before your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown.
After the procedure, you will be taken to a recovery area for observation and monitoring. It is important to lie flat for several hours to avoid bleeding. If the procedure was done at the groin, pressure may be placed at the site to prevent bleeding. If the catheter was inserted through the wrist, after the procedure you will be able to get up. A bandage will be placed at the insertion site. Depending on your condition, you will remain in the hospital for one or more days. Ask your health care team when you can shower, return to work, and resume other normal activities. Your puncture site will remain tender for a while. It may be slightly bruised and have a small bump. Your doctor will likely prescribe medications to prevent blood clots. It is important to follow your doctor’s instructions regarding the blood thinning medications.
Risks and complications include: -Dissection -Perforation -Arrhythmia -Thrombosis -Spasm Let your doctor know if you experience any symptoms such as: -Chest pain -Difficulty breathing -Sweating -Heart palpitations -Dizziness, fainting
What are the travel recommendations for this procedure:
Before the procedure: You should plan to stay in Thailand for at least one week through the duration of your treatment. It is recommended that you stay in a hotel close to the hospital for convenience in traveling to the hospital before and after the procedure or from the day of the procedure to the day of your follow-up appointment.
After the procedure: At your follow-up appointment you will undergo a physical examination and your wound will be checked. You will receive documentation regarding your surgery or procedure and all other relevant documentation for traveling. You will receive information about caring for yourself when you return home and be given the document “Recommendations for Going Home After Percutaneous Coronary Intervention.” Please read all information you are given carefully and follow your medical team’s instructions.
When traveling by air, if you are seated in Economy Class, please choose an exit row or bulkhead seat for convenience in getting up and moving around every 15-30 minutes. Flex your ankles regularly to prevent deep vein thrombosis. Please take all medication prescribed by your doctor. Carry the appropriate dosage of mediation in your carry-on luggage when you travel as well as a few extra doses in case of an emergency. Carry the prescription for all your medication to avoid problems at the airport.
What if the procedure isn’t performed?
Abnormalities within the narrowed/blocked blood vessel may not be discovered, preventing appropriate treatment.
What are the indications and contraindications of this procedure?
The indications include patients having coronary angiography or PCI for: -Assessment of intermediate stenoses (e.g., 40% to 70%) by angiography -Clarifying the anatomy where angiography is unclear a. Assessing lesions that are hazy on angiography for dissection, thrombus, intramural hematoma b. Assessing extent of calcification -Guiding chronic total occlusion PCI (e.g., to determine an intimal vs. medial or adventitial location) -Optimizing stent deployment (e.g., stent apposition, expansion, and edge dissections) -Assessing changes in plaque, arterial remodeling, and plaque composition Contraindications include: -Patients who cannot have anticoagulation during the procedure