Patient Resources

What is a percutaneous kidney biopsy?

Obtaining very small pieces of kidney tissue by a thin needle that is inserted through the skin to reach the kidney under ultrasound guidance. 

 

Reasons to have a kidney biopsy

A kidney biopsy is the gold-standard for many kidney diseases and might be needed if the cause is not clear from other blood, urine and/or imaging tests. In some cases, it will give critical information to guide therapy for specific types of kidney disease.

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How is a kidney biopsy performed?

You will be positioned, usually with you lying on your abdomen, so that your back is facing upwards. A real-time ultrasound will be done to check the position and depth of your kidney.

 

Once the doctor is happy with the position and access, this spot will be marked, and the skin thoroughly cleaned to minimise the risk of infection. You will then be given a strong local anaesthetic to numb the area and reduce any pain you may feel, although it may sting at the start for a few seconds while it starts to work. It is first injected near the surface of the skin and then deeper, along the path the needle will take from the skin to kidney.

 

You may feel a small amount of dull pressure as the needle is guided (using the ultrasound) from skin to kidney. You will be asked to hold your breath so the kidney doesn’t move, and a small sample of kidney biopsy will be taken. The biopsy tissue is approximately 1mm wide by 10-20 mm long. You will hear a loud “click” when the mechanism to get the biopsy is deployed.

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Before the biopsy

We will check your blood test to make sure there are no major bleeding disorders to make sure it is safe to proceed. We will also ask that you stop any blood thinners for a few days before. The duration you are off these medications will vary and we will discuss this**, but the common medications we stop include:

• Stop warfarin, apixaban, rivaroxaban, dabigatran or clexane (**)

• Stop aspirin, clopidogrel, prasugrel, ticagrelor, ticlopidine, dipyridamole (**)

• Avoid anti-inflammatory pain killers (diclofenac, celecoxib, indomethacin, ibuprofen – including maxigesic) and fish oil tablets in the 5 days before the procedure

 

Most other tablets will be safe and should be taken as usual before the biopsy, but again, we go through your medications and confirm this before the procedure.

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On the day of the biopsy

You will be required to attend the outpatient renal clinic (A6c) at Westmead Hospital for most of the day. Please arrive before 8:30am so the appropriate preparations can take place. The biopsy as described earlier will take approximately 20 minutes.

 

After the biopsy, you will be required to lay on your back (bed rest) to reduce the risk of bleeding. You will be monitored for the next 4 hours for any significant changes or pain. At the end of this period, you will need to provide a urine sample to make sure there is no visible blood before you can go home.

 

If at any stage there is suspicion of bleeding, staff will assess you and organise the appropriate tests and management. If there is any significant bleeding, you will be admitted for further monitoring.

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Risks associated with a kidney biopsy

Ultrasound guided, percutaneous kidney biopsies are generally safe but there are small risks involved with the procedure, which may include:

• Bleeding, which may require admission, transfusion, or specific treatment

• Infection

• Allergic reactions to the anaesthetics

• Insufficient kidney tissue obtained during the procedure

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After the biopsy

If any of the following occur, present to hospital emergency department, and let them know the symptoms and that you had a kidney biopsy performed recently.

• new pain near the site of the kidney biopsy or abdomen.

• bleeding, either from the skin

• blood in the urine (or difficulty passing urine)

• “dizziness”, shortness of breath

• Fever or high temperatures

• Swelling or pus at the skin where biopsy was performed.

 

If none of the above symptoms develop, you can resume your usual blood thinner medications once 48 hours has passed since the biopsy (on the 3rd day after the biopsy).

 

Avoid heavy lifting, strenuous exercise, or activity for the next 14 days to minimise the risk of late bleeding after the biopsy. A medical certificate can be provided for this if required, but you are able to resume work which otherwise does not involve heavy lifting or physically strenuous activity.

 

The results of the kidney biopsy will usually be available within 2 weeks and be discussed at the next appointment.

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