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Kidney Biopsy Test – Procedure, Risks & Results

March 28, 2018

A kidney biopsy is the removal of a small piece of kidney tissue for examination. The word “renal” describes the kidneys, so a renal biopsy is also called a kidney biopsy. The test helps your doctor identify the type of kidney disease you have, how severe it is, and the best treatment for it. Here’s all you need to know about the renal biopsy.

Types of Renal Biopsy

There are two ways to perform a renal biopsy:

  • Percutaneous biopsy (renal needle biopsy): This is the most common type of renal biopsy. For this procedure, a doctor inserts a thin biopsy needle through the skin to remove your kidney tissue. They may use an ultrasound or CT scan to direct the needle to a specific area of the kidney.
  • Open biopsy (surgical biopsy): For this procedure, your doctor makes a cut in the skin near the kidneys. This allows the physician to look at the kidneys and determine the area from which the tissue samples should be taken.


Need for a Renal Biopsy

Your doctor may order a kidney biopsy if you have:

  • A kidney problem that can’t otherwise be identified
  • An unexplained drop in kidney function
  • Blood in the urine that does not go away
  • Protein in the urine found during a urine test
  • A transplanted kidney, which needs to be monitored using a biopsy

Not everyone with these problems needs a kidney biopsy. The decision is based on your signs and symptoms, test results, and overall health.

Procedure for Renal Biopsy

The two most common ways to do a kidney biopsy are percutaneous and open. These are described below.

Percutaneous biopsy

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 (anaesthetic) 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.


Open Biopsy

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 (anaesthesia) 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 the 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.

Risks Associated with Renal Biopsy

Seek immediate medical attention if you find one or more of the symptoms.

  • Have bright red blood or blood clots in your urine for longer than 24 hours after your biopsy
  • Unable to urinate
  • Frequent or urgent need to urinate
  • Burning sensation when urinating
  • Have chills or a fever
  • Worsening pain at the biopsy site
  • Blood or pus from the biopsy site that saturates the bandage
  • Feel faint, dizzy or weak

In addition to infection, a renal biopsy — like any invasive procedure — carries the risk of potential internal damage to the targeted organ or nearby areas.

Renal Biopsy Results

Expect your biopsy report from the pathology lab within about a week. In urgent situations, a full or partial report may be available in less than 24 hours.

Normal Results

A normal result is when the kidney tissue shows normal structure.

Abnormal Results

An abnormal result means there are changes in the kidney tissue. This may be due to:

  • Infection
  • Poor blood flow through the kidney
  • Connective tissue diseases
  • Other diseases that may be affecting the kidney, such as diabetes
  • Kidney transplant rejection, if you had a transplant

Your doctor may decide to order additional tests to use to help make a treatment plan. They will go over your results and your condition in depth with you and discuss all the next steps following your renal biopsy.