A kidney biopsy is the removal of a small piece of kidney tissue for examination.
How the Test is Performed
A kidney biopsy is done in the hospital. The two most common ways to do a kidney biopsy are percutaneous and open. These are described below.
Percutaneous means through the skin. Most kidney biopsies are done this way. The procedure is usually done in the following way:
- You may receive medicine to make you drowsy.
- You lie on your stomach. If you have a transplanted kidney, you lie on your back.
- The doctor marks the spot on the skin where the biopsy needle is inserted.
- The skin is cleaned.
- Numbing medicine (anesthetic) is injected under the skin near the kidney area.
- The doctor makes a tiny cut in the skin. Ultrasound images are used to find the proper location. Sometimes another imaging method, such as CT, is used.
- The doctor inserts a biopsy needle through the skin to the surface of the kidney. You are asked to take and hold a deep breath as the needle goes into the kidney.
- If the doctor is not using ultrasound guidance, you may be asked to take several deep breaths. This allows the doctor to know the needle is in place.
- The needle may be inserted more than once if more than one tissue sample is needed.
- The needle is removed. Pressure is applied to the biopsy site to stop any bleeding.
- After the procedure, a bandage is applied to the biopsy site.
In some cases, your doctor may recommend a surgical biopsy. This method is used when a larger piece of tissue is needed.
- You receive medicine (anesthesia) that allows you to sleep and be pain-free.
- The surgeon makes a small surgical cut (incision).
- The surgeon locates the part of the kidney from which the biopsy tissue needs to be taken. The tissue is removed.
- The incision is closed with stitches (sutures).
After percutaneous or open biopsy, you will likely stay in the hospital for at least 12 hours. You will receive pain medicines and fluids by mouth or through a vein (IV). Your urine will be checked for heavy bleeding. A small amount of bleeding is normal after a biopsy.
Follow instructions about caring for yourself after the biopsy. This may include not lifting anything heavier than 10 pounds (4.5 kilograms) for 2 weeks after the biopsy.
How the Test will Feel
Numbing medicine is used, so the pain during the procedure is often slight. The numbing medicine may burn or sting when first injected.
After the procedure, the area may feel tender or sore for a few days.
You may see bright, red blood in the urine during the first 24 hours after the test. If the bleeding lasts longer, tell your provider.
How to Prepare for the Test
Tell your health care provider:
- About medicines you are taking, including vitamins and supplements, herbal remedies, and over-the-counter medicines
- If you have any allergies
- If you have bleeding problems or if you take blood-thinning medicines such as warfarin (Coumadin), clopidogrel (Plavix), dipyridamole (Persantine), fondaparinux (Arixtra), apixaban (Eliquis), dabigatran (Pradaxa), or aspirin
- If you are or think you might be pregnant
A normal result is when the kidney tissue shows normal structure.
- Bleeding from the kidney (in rare cases, may require a blood transfusion)
- Bleeding into the muscle, which might cause soreness
- Infection (small risk)
What Abnormal Results Mean
An abnormal result means there are changes in the kidney tissue. This may be due to:
Why the Test is Performed
Barisoni L, Arend LJ, Thomas DB. Introduction to renal biopsy. In: Zhou M, Mari-Galluzzi C, eds. Genitourinary Pathology: Foundations in Diagnostic Pathology. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 7.
Topham PS, Chen Y. Renal biopsy. In: Johnson RJ, Feehally J, Floege J, eds. Comprehensive Clinical Nephrology. 5th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 6.