What is a kidney biopsy?
A biopsy is done to remove tissue or cells from the body to exam under a microscope. The tissue sample is removed with a needle to check for cancer or other abnormal cells. It also helps check how well the kidney is working.
There are 2 types of kidney biopsies:
- Needle biopsy. After an anesthetic is given, the healthcare provider inserts the biopsy needle into the kidney to get a sample. Ultrasound or computed tomography (CT scan) may be used to guide the needle. Most kidney biopsies are done using this technique.
- Open biopsy. After an anesthetic is given, the healthcare provider makes an incision in the skin and surgically removes a piece of the kidney.
If your healthcare provider wants to sample a specific area of the kidney, the biopsy may be guided by ultrasound, fluoroscopy, or CT.
Why might I need a kidney biopsy?
Your kidneys are a pair of purplish-brown organs. They sit below the ribs toward the middle of the back. The kidneys:
- Remove liquid waste from the blood in the form of urine
- Keep a balance of salts and other substances in the blood
- Produce erythropoietin, a hormone that helps form red blood cells
- Regulate blood pressure
When your kidney function is abnormal, a kidney biopsy may be done to:
- Find out the reason for poor kidney function
- Check how well a transplanted kidney is working.
There may be other reasons for your healthcare provider to advise a kidney biopsy.
What are the risks of a kidney biopsy?
As with any procedure, complications can happen including:
- Bruising and discomfort at the biopsy site
- On-going bleeding from the biopsy site, in the urine, or inside the body
- Puncture of nearby organs or structures
- Infection near the biopsy site
If the kidney biopsy is done with the aid of X-ray, the amount of radiation used is small. Therefore, the risk for radiation exposure is low.
If you are pregnant or think you may be, tell your healthcare provider. Talk with your healthcare provider about the risks to the fetus from being exposed to an X-ray. Pregnancy does not always mean you can't have a kidney biopsy. It may be important for the health of the mother. Special precautions may be taken to protect both the mother and the fetus during a kidney biopsy.
You may not be able to have a kidney biopsy if you have an active kidney infection, certain bleeding conditions, uncontrolled high blood pressure, or have only one working kidney.
There may be other risks depending on your specific medical condition. Be sure to raise any concerns with your healthcare provider before the procedure.
How do I get ready for a kidney biopsy?
- Your healthcare provider will tell you about the procedure, and you can ask questions.
- You will be asked to sign a consent form that gives your permission to do the kidney biopsy. Read the form carefully and ask questions if something is not clear.
- Your healthcare provider may do a physical exam to be sure you are in otherwise good health. You may have blood tests or other diagnostic tests.
- Tell your healthcare provider if you are sensitive to or are allergic to any medicines, latex, tape, and anesthesia.
- Tell your healthcare provider of all medicines (prescribed and over-the-counter) and herbal supplements that you are taking.
- Tell your healthcare provider if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medicines, aspirin, or other medicines that affect blood clotting. You may need to stop these medicines before the procedure.
- If you are pregnant or think you might be, tell your healthcare provider before the procedure.
- You may be asked to fast before the biopsy, generally after midnight or at least 6 hours before getting anesthetic or sedatives. Your healthcare team will give you specific instructions.
- You may get a sedative before the procedure to help you relax. Because the sedative may make you drowsy, you will need to arrange for someone to drive you home.
- Based on your medical condition, your healthcare team may request other specific preparations.
What happens during a kidney biopsy procedure?
A kidney biopsy may be done on an outpatient basis or in a hospital. It may be done in a procedure room, in a hospital bed, or in the radiology department. Procedures may vary depending on your condition and your healthcare provider’s practices.
Generally, a kidney needle biopsy follows this process:
- You will remove your clothing and put on a hospital gown.
- An intravenous (IV) line may be started in your arm or hand.
- You will lie on your stomach so that the healthcare provider can easily reach the kidney. A pillow may be used to hold you in the right position. If you have a transplanted kidney, you will lie on your back.
- The skin over the biopsy site will be cleaned with an antiseptic solution.
- You will feel a needle stick when the local anesthetic is injected. This may cause a brief stinging sensation.
- You will need to lie still during the procedure.
- Ultrasound or X-ray may be used to guide the needle into the kidney.
- You will be asked to breathe in and hold your breath while the healthcare provider inserts the biopsy needle into the kidney. This prevents movement of the diaphragm, which may interfere with the placement of the biopsy needle.
- You may feel discomfort or pressure when the healthcare provider takes the sample.
- There may be more than one puncture if the healthcare provider needs more than one tissue sample. If so, the same puncture process will be repeated.
- When the needle is withdrawn, firm pressure will be applied to the biopsy site to stop bleeding.
- A sterile bandage or dressing will be applied.
- The kidney tissue sample will be sent to the lab for testing.
- Talk with your healthcare provider about what you will have during your kidney biopsy.
What happens after the kidney biopsy?
Your recovery will vary depending on the type of procedure done and your healthcare provider's practices. You may be taken to the recovery room and watched closely as the anesthesia wears off. Once your blood pressure, pulse, and breathing are stable and you are alert, you may be taken to a hospital room or discharged to your home.
You will be asked to lie on your back for several hours. A nurse will check your urine for signs of bleeding. You may have blood tests to check for internal bleeding. You may be discharged later the same day or the next day. If you had a sedative or anesthetic, plan to have someone drive you home.
The biopsy site may be tender or sore for several days after the biopsy. Take a pain reliever for soreness as advised by your healthcare team. You may be told to not take aspirin or certain other pain medicines that may raise the chance of bleeding. Be sure to take only recommended medicines.
Tell your healthcare team to report any of the following:
- Blood in your urine after the first 24 hours
- Inability to urinate
- Fever and/or chills
- Redness, swelling, or bleeding or other drainage from the biopsy site
- Increased pain around the biopsy site or elsewhere
- Feeling faint
You may get back to your usual diet unless told otherwise. Your healthcare team may ask you to rest for a day or two. Do not do strenuous physical activity for several days. Do not do any type of “bouncing" activities, such as jogging, aerobics, playing tennis, or horseback riding for a couple of weeks to prevent bleeding of the biopsy site.
Your healthcare provider may give you other instructions after the procedure, depending on your situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure