What is IVUS?
Intravascular ultrasound (IVUS) is a medical technique for seeing inside blood vessels using soundwaves. A computer produces pictures of soft tissues. This technique allows physicians to see areas that they can't see with X-rays.
IVUS is also known as intravascular echocardiography or endovascular ultrasound.
How Does IVUS Examination Work?
A transducer or probe emits the soundwaves that bounce off the soft tissues creating an echo. The probe travels to the target area via a catheter inserted into a vein or artery. The other end of the catheter connects to a computer. The computer uses the echoes to create a clear image showing the physician the inside of your arteries or veins.
Above IVUS image is inside of a blood vessel. The black part in the middle is where the blood travels. The grey area is tissue. This image shows plaque build up in the artery.
Why Use IVUS?
Intravascular ultrasound is a useful tool for assessing the condition of internal structures:
- Assessing the narrowing of veins.
- Looking for blood clots in legs, blood clots in feet, or any other extremities.
- Measuring blood vessels to select stent sizes.
- Diagnosing peripheral artery disease.
- Reveal more information about plaque build up in the arteries.
IVUS is also a partner to other procedures allowing the doctors and medical technicians to track progress and effectiveness.
What Happens During IVUS?
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.
Follow up with CVM
Routine follow-up for surveillance is vital after your procedure to detect short and long-term complications early. Center for Vascular Medicine recommends follow-up post-operatively at approximately 1 week, 6 weeks, 3 months, 6 months, 1 year, and then once every year further. Every other visit should involve ultrasonography unless otherwise indicated by your vascular specialist.
Benefits of IVUS
This procedure using ultrasound to gain a clear image of the inside of your blood vessels has many benefits:
- Your physician can see and measure the amount of plaque in the arteries.
- Measuring the narrowing of blood vessels and assessing the need for treatment.
- Finding out what makes up the plaque deposits.
- Placing stents accurately in veins and arteries.
- Reduced risk of stent thrombosis.
- Finding areas of vein compression and increased risk of clots.
- Tissues avoid exposure to ionizing radiation.
- Check up on blood vessels after a procedure to look for further narrowing.
- No exposure to radiation.
Preparing for IVUS
IVUS is a procedure that doesn't need any special pre-procedure planning. Still, if you have it with another procedure, you may have specific fasting or other instructions for that medical intervention.
The general advice is to wear comfortable loose clothing and to leave your jewelry and watches at home. Naturally, you need to discuss any medication and underlying health issues with your physician - especially kidney disease or diabetes. As is expected, you will go through a checklist and some health recommendations like switching to a healthy diet and stopping smoking.
Risks of IVUS
Any medical procedure that involves putting something into your blood vessels carries an element of risk. Still, your doctor is aware of these and will monitor and take steps to mitigate any issues. Possible problems related to anesthesia includes:
- Irregular heart rhythms (arrhythmia)
- A blood clot otherwise known as Deep Vein Thrombosis
- An allergic reaction to the medications used during the procedure
- In very rare cases, a heart attack, stroke, or blood clot in the lung
You will get aftercare instructions for when you return home. Generally, rest for 24 hours to give your body time to recover from the procedure. It makes sense to drink plenty of fluids and don't do any heavy lifting.
You need to pay attention to the leg where the procedure took place and contact your physician if you experience any issues. Problem signs are pain, warmth (maybe an infection), bleeding, swelling, or a change in color. Most patients do not experience any difficulties following IVUS.
Depending on what your doctor notices in the IVUS scan and your symptoms he may get need a better view of your arteries and veins using the following procedures:
Angiogram Procedure - Look inside your arteries with advanced imaging devices using dyes to view details we can't see with an IVUS examination.
Venogram Procedure - Look inside your veins with advanced imaging devices using dyes to view details we can't see with an IVUS examination.