A renal angioplasty is a way of relieving a blockage in the renal artery, the main blood vessel to the kidney, without having an operation. A fine plastic tube, called a catheter, is inserted through a blockage in an artery, and a special balloon on the catheter is then inflated, to open up the blockage and allow more blood to flow through it. Kidney arteries often require the insertion of a tiny hollow tube called a stent to keep it open after the procedure.
Why do I need an angioplasty?
Renal angioplasty is usually done to protect the kidney from further damage due to loss of the blood supply. The blood supply may be slowly reducing over a long time or may have happened suddenly causing kidney pain. Your doctors know that there is a problem with part of your circulation. You may already have had an angiogram, which has shown a blockage in an artery.
Who has made the decision?
The doctors in charge of your case, and the radiologist doing the angioplasty, will have discussed the situation, and feel that this is the next step. However, you will also have the opportunity for your opinion to be taken into account, and if, after discussion with your doctors, you do not want the procedure carried out, then you can decide against it.
Who will be doing the angioplasty?
A specially trained doctor called a radiologist. Radiologists have special expertise in using x-ray equipment, and also in interpreting the images produced. They need to look at these images while carrying out the procedure.
Where will the procedure take place?
Generally in the x-ray department, in a special "screening" room, which is adapted for specialised procedures.
How do I prepare for an angioplasty?
You need to be an in-patient in the hospital. You will probably be asked not to eat for four hours beforehand, though you may be told that it is alright to drink some water. You may receive a sedative to relieve anxiety. You will be asked to put on a hospital gown.
If you have any allergies, you must let your doctor know. If you have previously reacted to intravenous contrast medium, the dye used for kidney x-rays and CT scanning, then you must also tell your doctor about this.
What actually happens during an angioplasty?
The procedure starts off in exactly the same way as an angiogram, and if you have already had this performed, you will know what to expect.
You will lie on the x-ray table, generally flat on your back. You need to have a needle put into a vein in your arm, so that the radiologist can give you a sedative or painkillers. Once in place, this will not cause any pain. You may also have a monitoring device attached to your chest and finger, and may be given oxygen through small tubes in your nose.
The radiologist will keep everything as sterile as possible, and will wear a theatre gown and operating gloves. The skin near the point of insertion, probably the groin, will be cleaned with antiseptic, and then most of the rest of your body covered with a theatre towel.
The skin and deeper tissues over the artery will be anaesthetised with local anaesthetic, and then a needle will be inserted into the artery. Once the radiologist is satisfied that this is correctly positioned, a guide wire is placed through the needle, and into the artery. Then the needle is withdrawn allowing the fine, plastic tube (catheter) to be placed over the wire and into the artery.
The radiologist will use the x-ray equipment to make sure that the catheter and the wire, are moved into the right position, very close to the blockage in the artery. Then the wire and the catheter will be moved so that they pass into the narrowed area, and the balloon is then inflated. This may need to be done several times in order for the narrowed area to open up sufficiently to improve the blood flow. It is quite possible that a metal stent (like a cylinder) may be placed across the narrowing and left in place to hold the artery open.
The radiologist will check progress by injecting contrast medium down the catheter to show how much the narrowed artery has opened up. When he or she is satisfied that a good result has been obtained, the balloon is deflated and the catheter is removed. The radiologist will then press firmly on the skin entry point for several minutes, to prevent any bleeding.
Will it hurt?
When the local anaesthetic is injected, it will sting to start with, but this soon wears off, and the skin and deeper tissues should then feel numb. After this, the procedure should not be painful. There will be a nurse, or another member of clinical staff, standing next to you and looking after you. If the procedure does become uncomfortable for you, then they will be able to arrange for you to have some painkillers as appropriate.
As the dye, or contrast medium, passes around your body, you may get a warm feeling, which some people can find a little unpleasant. However, this soon passes off and should not concern you. You may also feel that you are passing water as the dye travels through the arteries to your bladder - again this passes off very quickly.
How long will it take?
Every patient's situation is different, and it is not always easy to predict how complex or how straightforward the procedure will be. Some angioplasties take about an hour. Other angioplasties may be more involved, and take rather longer. As a guide, expect to be in the x-ray department for about an hour and a half altogether.
What happens afterwards?
You will be taken back to your ward on a trolley. Nurses on the ward will carry out routine observations, such as taking your pulse and blood pressure, to make sure that there are no problems. They will also look at the skin entry point to make sure there is no bleeding from it. You will generally stay in bed for a few hours, and you will usually be kept in hospital overnight.
Most patients will be given Aspirin and/or other drugs to improve blood flow in their arteries, and to try to limit the chance of a similar condition occurring again.
Are there any risks or complications?
Angioplasty is generally a very safe procedure, but there are some risks and possible complications. The most obvious possibility is of failure - it may not be possible to open up the artery as hoped, or it may be that the small arteries beyond the narrowing are discovered to be also badly diseased.
Risks to the artery in the groin Quite often a small bruise ('haematoma') forms around the site where the needle has been inserted. If this becomes a large bruise, then there is a risk of it getting infected, and it may require treatment with antibiotics. Very rarely, some damage can be caused to the artery by the catheter, or the balloon, and this may need to be treated by an operation or another radiological procedure.
Risks to the kidneys Damage can occur in two or three ways.
The contrast material used to show up the arteries may temporarily worsen kidney function. This is more likely if you have poor kidney function, are a diabetic, or are taking some particular drugs. Blocking the artery Very occasionally the attempts to open up the artery actually end up blocking it, and kidney function gets worse, not better. It is also possible to burst the artery at the point of narrowing - this is very rare but may require emergency treatment.
Damage to other arteries Moving tubes around in narrowed arteries can knock off tiny bits - 'atheroemboli' - which fly off and block much smaller arteries in the feet, in the kidney, or elsewhere. This is more likely if the aorta (the major blood vessel from the heart) is badly narrowed, and occasionally it causes serious trouble, for instance leading to kidney failure, or a need to amputate toes or even limbs. Very rarely this can be fatal.
Because of the rare occurence of these serious complications, it is important to discuss what the risks are in your case with the radiologist and with the other doctors looking after you. The risks are quite low for most people, but may be high for others. overall the risk of you experiancing a significant complication is about 1 in 20 (5%). Because the risks and benefits are sometimes not certain, you may be asked to take part in a Trial that compares different treatments.
Some of your questions should have been answered by this information, but remember that this is only a starting point for discussion about your treatment with the doctors looking after you. Make sure you are satisfied that you have received enough information about the procedure, before you sign the consent form.
|Angioplasty is generally simpler and safer than the alternative of having an operation|
|Renal angioplasty can usually be done in a very short hospital admission|
|There are some risks and possible complications from renal angioplasty - usually the risks are low, but in some patients they may be quite high|
|Very occasionally renal angioplasty causes permanent loss of kidney function|
Acknowledgements: The authors of this page were Ian Gillespie and Neil Turner. It was first published in August 2001 and reviewed by Paddy Gibson in April 2010. The date is was last modified is shown in the footer.