Ultrasound Guided Kidney (Renal) Biopsy

This leaflet explains what an ultrasound guided kidney biopsy is, what is involved and the possible risks.

It is important that you feel that you have had enough information before you sign the consent form and undergo the procedure. This leaflet does not replace the discussion with your doctor but will hopefully help you to have a more informed discussion.

What is an ultrasound guided kidney biopsy?

A kidney biopsy is a procedure where a small sample of kidney tissue is taken under ultrasound guidance and with local anaesthetic. This means medication is injected to make the skin and tissues around the kidney numb to prevent pain in that area. You will be awake for this procedure.

It is done by a radiologist who is a doctor specialised in medical imaging. The sample is sent to a doctor who specialises in looking at parts of the body under a microscope to make a diagnosis.

Your doctor has referred you for this procedure so that the cause for your medical problems can be determined. This will help your doctor to discuss the best treatment options with you.

Are there alternatives?

Although imaging and blood tests may suggest a diagnosis, the only way to be certain is to look at a sample under a microscope. The benefit of this procedure is that it may make a specific diagnosis.

What do I have to do before my procedure?

• If you are not already in hospital, you will receive an appointment letter or a mobile phone text message that will tell you which ward to attend and at what time. You will probably be able to go home on the same day.
• Occasionally, some people need to stay overnight, therefore you should bring some overnight clothes and toiletries.
• You can eat and drink, as normal, before the procedure. You should take your usual tablets and medication unless we have told you otherwise.

If you are on blood-thinning medication, you must inform your doctor and the Radiology Secretaries, so you are given the appropriate instructions on when to stop and resume your blood-thinning medication. Examples of these medications include warfarin, apixaban, edoxaban, rivaroxaban, dabigatran, heparin, fondaparinux, tinzaparin, clopidogrel, ticagrelor, dipyridamole and aspirin.

• You will have some blood tests to measure the number of red cells and to check your blood clotting. If the blood tests are abnormal, you may need to receive some medication or a blood transfusion before the procedure.
• Your average resting blood pressure should be below 160/90mmHg to reduce the risk of bleeding. You will need to monitor your resting blood pressure at home for at least 7 days before the date of your biopsy. You will need 3 readings in the morning and 3 readings in the evening. These readings need to be discussed with your kidney doctor, as they may need to adjust your blood pressure medication to achieve this target prior to your kidney biopsy.
• A member of the clinical team will explain the procedure and ask you to sign a consent form. You will be asked to change into an x-ray gown on the ward and will be taken down to the Ultrasound department.

What happens during my procedure?

You will be asked to lie flat on your stomach or on your side. The radiologist will perform an ultrasound to identify the best place to perform the biopsy and will make a small mark on your skin. Ultrasound gel is placed on your body and a small device is moved over the skin.

A computer produces an image of your kidney and surrounding areas. The skin around the planned biopsy site will then be cleaned with cleaning fluid which may feel a little cold. Sterile drapes will be placed around the planned area for biopsy.

The area will be numbed using local anaesthetic and once this has taken effect, the biopsy needle is inserted through the skin into the kidney while watching with the ultrasound. One or more samples are taken. Each time a sample is taken, there is a clicking noise a bit like a stapler. The sample is then checked immediately under the microscope to see if there is enough tissue for examination.

The whole procedure normally takes no more than 30 minutes.

What happens after the procedure?

A plaster is put over the skin. You will be kept under close observation on the ward to monitor for complications. To help prevent bleeding, you need to lie flat for 3½ hours, then sit up in bed for 30 minutes and then you can slowly begin to move.

A nurse will record your blood pressure and pulse regularly. They will also check your biopsy site and check that you have passed urine before you leave. You are advised to avoid heavy lifting or vigorous exercise for 7 days and avoid driving for at least 24 hours and not before you feel you are able to perform an emergency stop.

What are the possible complications/risks during my kidney biopsy?

Minor complications include pain which may need simple painkillers such as paracetamol, bruising and introducing infection. Blood can be seen in the urine for a few days in about 1 in every 10 patients and this usually settles on its own. If the bleeding is more significant, you may need the insertion of a urinary catheter which is a small soft plastic tube inserted through the urine hole in the penis in men or the vulva in women and admission to hospital for observation.

More serious complications are uncommon, these include:

• bleeding which needs a blood transfusion – 1 in 50 or 2%
• bleeding which requires an operation or another procedure – 1 in 500 or 0.2%
• damage to the kidney requiring an operation to remove it – 1 in 3000 or 0.03%
• damage to nearby structures such as the bowel, lung, spleen this is very unusual, though may require observation and/or intervention

Death following kidney biopsy has occurred but is extremely rare.

How do I get my results?

Your consultant will receive the result of your ultrasound guided kidney biopsy. You may already have a follow-up appointment with the consultant but, if not, an appointment will be sent through the post or by mobile phone text message. Due to specialist tests needed on the biopsy this may take several weeks.

If you need to contact us:

If you need to change your appointment, request an interpreter or need advice, contact us on 01274 365499. The office is open between 8.30am and 4.30pm Monday to Friday except for Bank Holidays.