What is a kidney biopsy?
A kidney biopsy is a test that involves collecting small pieces of the kidney by a needle for examination with a microscope.
Why is a kidney biopsy done?
A kidney biopsy can help in forming a diagnosis, choosing the best course of treatment, or help in providing a prognosis (predicting outcomes). For any of the below-mentioned conditions kidney biopsy could be recommended:
- Hematuria (blood in urine)
- Proteinuria (protein in urine)
- Impaired kidney function
- Impaired function of kidney transplant
What are the pre-procedure preparations for a kidney biopsy?
- You will need to be hospitalized for 24 hours.
- You will need to sign a consent form after understanding the risks and benefits of the biopsy.
- Please avoid aspirin and other blood-thinning medicines for at least one week before the procedure (if you have been prescribed such medicines, please discuss with your kidney doctor when you should stop them before the biopsy and when to resume them after the biopsy)
- Inform your doctor of any drug allergies
What is the procedure for a kidney biopsy?
- You will need to lie on your stomach for positioning the kidneys, which are in the back. If a transplant kidney biopsy is to be done, you will lie on your back.
- The site of the biopsy will be cleaned and you will be injected with a local painkiller at the site planned for the biopsy. You may feel pressure but should not feel pain after this. If you feel pain, then please let the doctor know and they can inject more local painkillers.
- The doctor will locate the kidneys using an ultrasound machine.
- You may be asked to hold your breath at the time of the biopsy
- When the biopsy needle is inserted and kidney tissue is taken the instrument will produce a sharp clicking sound. Do not be alarmed by it. The doctor may insert the needle 3-to 4 times to collect an adequate sample.
- The whole procedure takes about an hour including location/cleaning/injection and sampling.
What happens after a kidney biopsy?
You will have to lie in bed straight for 6 hours and after 6 hours can turn in bed but will get out of bed the next morning.
Nurses will monitor your urine output, blood pressure, and pulse.
You will be given collection bottles for collecting consecutive urine samples. If urine is clear then keep three samples. If the urine has some blood in it then keep collecting till you are discharged or the blood clears.
When and how will I get the biopsy report?
Normally routine biopsy reports take 3-5 days for reporting. However, consult your primary doctor when you would like to see you next. In urgent cases, a preliminary report may be given within 24-36 hours.
What are the potential problems of a kidney biopsy?
- Kidney biopsy is a safe procedure with low risks. Most of these complications are rare and manageable.
- Micro hematuria (blood in urine seen only by microscope) -universal
- Gross hematuria (blood in urine, visible to you, usually resolves in a few hours) -3-18%
- Perirenal hematoma on CT scan (bleeding around the kidney) -60-80%
- Need for blood transfusion -1-6%
- Angiography/embolization (procedure to block a bleeding vessel)
