Angioplasty and Stent Insertion
Dr William Clark
Dr James Burnes
Date last modified: December 08, 2015
1. What is an angioplasty and stent insertion?
Angioplasty and stent insertion is used to treat narrowing in an artery. Angioplasty uses a small, sausage-shaped balloon to stretch the artery open and improve blood flow. The stent is a small, metal cylinder that acts like a small scaffold to hold the artery permanently open. Angioplasty is the name of the procedure carried out with the assistance of an angiogram, a special kind of X-ray image or picture that shows the arteries live on a screen.
The procedure starts with an angiogram and is carried out through a skin puncture into the blood vessel that feeds the narrowed or diseased vessels. Most often, the skin puncture is in the groin, at the top of the leg. Less commonly, you may need to have the skin puncture in your upper arm, if the blood vessel in the groin cannot be used.
A liquid contrast agent (sometimes referred to as contrast medium or dye) is injected into the artery to show the blood vessels on an X-ray image. Without contrast injection, blood vessels are invisible on X-rays. Angioplasty and stent insertion is carried out using the live images that are displayed on a television screen to guide the procedure.
Cardiologists (doctors specialising in disorders of the heart) carry out stent insertions into the coronary (heart) arteries. Radiologists (specialist doctors) carry out angioplasty and stent insertion in all other arteries in the body.
2. How do I prepare for an angioplasty and stent insertion?
Depending on the hospital or radiology practice where you are having the procedure done, you may be required to fast before the procedure (that means to go without food and water) for 4 hours prior to the procedure. The hospital or radiology practice will inform you if you need to fast.
Contrast medium is used to carry out angiograms, and if you have a history of kidney disease, this places some strain on the kidneys. If you have abnormal kidney function or diabetes, one kidney rather than two, or other medical conditions that may increase the risk to your kidney function if you have contrast injection, then special precautions are required. One of these precautions can be to give you extra fluid through an intravenous drip both before and after the procedure. Also, if you are on the blood thinning medication warfarin, an INR blood test will be needed to assess how ‘thin’ the blood is before the procedure (see iodine-containing contrast medium). This should be discussed with your referring doctor or specialist and the radiologist who is carrying out the procedure.
3. What happens during an angioplasty and stent insertion?
The procedure is usually not painful, but it is normal to be anxious before undergoing any procedure and you will normally be given a light sedation to help you relax.
- Local anaesthetic is then injected into the skin and soft tissues, and around the artery that will be used to gain access to the blood vessels that require treatment. This artery is usually the one in front of the hip or groin region, called the femoral artery.
- A needle is passed into the anaesthetised artery and then a soft and flexible guidewire is passed through the needle into the artery. A sheath is then passed over the wire and into the artery. The sheath is a plastic tube with a tap on one end. It usually measures 2–3 mm (1/8 inch) in diameter. Once the sheath is in place, the balloons and stents are all passed through this sheath.
- A very thin tube is then passed through the sheath into the narrowed artery and an angiogram picture is taken. Using this picture, the correct sized balloon is chosen. Angioplasty is carried out by passing a thin tube into the artery. The tube is called a balloon angioplasty catheter and has an inflatable balloon on the end of it. The balloon is shaped like a long sausage when it is inflated. The correct balloon size is selected for the artery being treated.
- The balloon is inflated where the artery is narrow and stretches the artery up to normal size. This procedure can be carried out for arteries almost anywhere in the body. After the balloon has been inflated for up to 3 minutes, it is deflated and removed. Another tube is passed into the artery to inject contrast medium. The contrast medium is injected while X-rays are being taken to provide an angiogram showing images of the new shape of the artery.
- Sometimes, the angioplasty is enough to keep the artery open, but on many occasions a stent is required to hold the artery open. A stent is a metal tube that is inserted into the artery through the same sheath in the groin region. It acts as a scaffold to prevent the narrow section of artery collapsing back. A stent stays in the artery permanently.
- The sheath is removed from the groin and an arterial closure device is sometimes inserted to close the artery and stop the bleeding. Alternatively, pressure (either with the doctor’s or nurse’s finger over the puncture site or with a clamp) is applied to the puncture site to stop the artery from bleeding. You must lie flat for between 1 and 4 hours after this.
4. Are there any after effects of an angioplasty and stent insertion?
- You might experience some discomfort in the groin (at the site of the puncture), like a bruise.
- You may develop a bruise in the groin. This only matters if it is associated with a hard lump that can be felt with your finger or significant/increasing pain. This is called a pseudoaneurysm. If this happens, you should immediately contact the practice where you had your procedure carried out to report this to the radiologist, because it may represent a localised injury to the vessel wall that needs special treatment.
- There may also be some discomfort at the site of the stent, as the artery becomes accustomed to having a stent within it. This is usually mild (and often non-existent), but if it does occur, it usually subsides over a week. It is most strongly felt when long stents are used in leg arteries.
5. How long does an angioplasty and stent insertion take?
The procedure varies, but in most cases it takes between 30 and 60 minutes to complete.
6. What are the risks of an angioplasty and stent insertion?
The risks of the procedure depend on which artery is being treated. General risks include the following:
- Bleeding/bruising at the groin puncture (approximately 3-5% of cases). This can be a problem requiring further treatment to either stop the bleeding or, even less commonly, to repair an injury to the vessel wall (this injury is called a pseudoaneurysm). Pseudoaneurysm at the puncture site will feel and look like a local lump that stays there for days to weeks after the procedure is finished. It is rarer than simple persistence of bleeding from the puncture site, but does require further treatment by the radiologist.
- Blocking the treated artery, making your symptoms worse in the short-term. The artery may close completely in approximately 1% of cases.
- Allergic reaction to intravascular contrast medium. Most reactions are mild, but very rarely can be severe (see Iodine-containing contrast medium).
- Kidney failure - this can occur if you have diabetes or chronic kidney dysfunction and especially if adequate preventative steps are not taken (see Contrast Medium: Gadolinium versus Iodine in patients with kidney problems). You will have your kidney function assessed by blood testing before the procedure to see if you need these preventative steps (which usually consist of ensuring that you are well hydrated, and this may mean having an intravenous drip inserted to give you extra fluids before and after the procedure).
- Allergic reaction to the sedation drugs or any other medications that are used.
7. What are the benefits of an angioplasty and stent insertion?
The procedure re-opens the artery to restore blood flow. The benefits provided by this restoration of blood flow depend on the artery being treated.
In the case of leg arteries, this may help you to walk without pain or allow a wound/ulcer on the leg or foot to heal. In the kidney arteries, it might help reduce abnormally high blood pressure or preserve kidney function. When carried out on an artery supplying the bowel, it may stop abdominal pain if this pain is due to reduced blood supply to the bowel. When carried out on the carotid artery (supplying the brain), it may prevent stroke.
8. Who does the angioplasty and stent insertion?
The procedure is carried out by a radiologist. A radiologist is a specialist doctor who has extra training to allow for the use of X-ray equipment to carry out interventional procedures like angioplasty and stent insertion. A radiographer is a trained health professional who helps the radiologist to operate the imaging equipment.
Special radiology nurses also assist the radiologist to complete the procedure and to care for you.
9. Where is an angioplasty and stent insertion done?
The procedure is carried out in an interventional radiology suite. This is like an operating room, but contains specialist X-ray equipment (high quality DSA (Digital Subtraction Angiogram) machine) that allows the radiologist to ‘see’ inside the body using X-rays.
10. When can I expect the results of my angioplasty and stent insertion?
The time that it takes your doctor to receive a written report on the test or procedure you have had will vary, depending on:
- The urgency with which the result is needed;
- The complexity of the examination;
- Whether more information is needed from your doctor before the examination can be interpreted by the radiologist;
- Whether you have had previous X-rays or other medical imaging that need to be compared with this new test or procedure (this is commonly the case if you have a disease or condition that is being monitored to assess your progress);
- How the report is conveyed from the practice or hospital to your doctor (i.e. phone, email, fax or mail).
Please feel free to ask the private practice, clinic or hospital where you are having your test or procedure when your doctor is likely to have the written report.
It is important that you discuss the results with the doctor who referred you, either in person or on the telephone, so that they can explain what the results mean for you.
11. Useful websites about angioplasty and stent insertion:
12. What are the prerequisites for having an angioplasty and stent insertion done?
Angioplasty can be carried out for a variety of clinical indications. The most common is for the treatment of lower limb ischaemia due to arterial narrowing with atheroma. Other vessels, such as the renal, mesenteric and carotid arteries, can be treated with angioplasty. However, the role of maximal medical therapy versus surgery versus angioplasty for these conditions is a complex issue. The decision to carry out angioplasty will involve an evaluation of the patient’s clinical problem, weighing risk of the procedure versus potential benefit based on the evidence, and the patient’s preferences. It is beyond the scope of this information item to provide a detailed discussion of the evidence regarding the role of angioplasty for various conditions compared with alternative medical and surgical therapy.
Other considerations prior to referral for angioplasty include:
- If a female patient is of child-bearing age, then a pregnancy test is strongly recommended, as the radiation dose to the abdomen from abdominal interventional radiological procedures may be significant in terms of the dose to the foetus.
- It is routine to obtain U, E, Cr and eGFR. In patients with renal function impairment (eGFR < 60) the single most effective way to reduce the likelihood or severity of CIN is intravenous normal saline administration before and after the procedure. The exact amount and rate of administration will depend on patient size and comorbidities, such as active/treated cardiac failure.
Preliminary imaging tests, such as ultrasound, CT angiography or diagnostic angiogram, will usually have been carried out to confirm an arterial abnormality.
17. Useful websites about angioplasty and stent insertion: