A kidney biopsy is a diagnostic medical test that involves the removal and study of small pieces of your kidney. It’s a way for your medical team to gather information to help diagnose or monitor certain ongoing health problems. Compared to other kinds of medical tests — like collecting blood and urine samples — the kidney biopsy procedure is much more in-depth.
It’s best to be well informed before undergoing this procedure because it requires time for preparation and recovery.
What Is a Kidney Biopsy?
A kidney biopsy is a fairly complicated diagnostic test. The goal is to gather as much information as possible about the state of your kidney’s health by looking at actual tissue samples. A doctor removes the samples from your body — using any of a number of methods — and then sends them off to a laboratory. Then it’s studied under a microscope. A trained medical professional will look for signs of particular issues and conditions.
Why Would a Kidney Biopsy Be Done?
There are many different ways to detect and monitor kidney problems, including:
These are all simpler procedures than a kidney biopsy. But there are plenty of situations when your medical team needs more information than these tests can provide. This is when they’ll need to conduct a kidney biopsy.
Situations that could cause your doctor to order a kidney biopsy include:
- The presence of blood in your urine
- The presence of protein in your urine
- Concerning blood test results that require further investigation
- The presence of a kidney tumor
- A poorly functioning transplanted kidney
Your medical team can use a kidney biopsy to gather a lot of different information on this organ. The types of information that they can obtain from this biopsy include:
- Whether or not your kidney is inflamed or infected
- The regions of your kidney that are most affected by a particular problem or treatment
- The way that your kidney is responding to a particular treatment approach
- The total amount of damage that a particular problem or treatment has done to your kidney
Your medical team will then use this information to help them reach a diagnosis or make decisions about an ongoing treatment plan. Conditions that a kidney biopsy can help diagnose include kidney disease with no clear cause — this is true for both acute and long-term versions of the condition — and kidney cancer. The biopsy can show whether or not a tumor is cancerous.
What Does Kidney Biopsy Preparation Involve?
You’ll likely need to do a number of things to prepare for your kidney biopsy. The exact steps depend on your unique needs and the removal method that your medical team will use. When your doctor schedules this test, they’ll let you know the specific steps that will get you ready for the procedure.
Preparatory steps that you may need to take include:
- Stopping any blood-thinning medications two weeks before the procedure
- Stopping the use of over-the-counter pain medications that can also have blood-thinning effects — like aspirin, ibuprofen, and naproxen
- Cutting out natural supplements that could affect your blood, like fish oil — ask your doctor for a full list and when you’ll need to stop taking them
- Stopping prescription medications — your doctor will give you the exact details on a case-by-case basis
- Going in for blood and urine samples to test for infections — you can’t get a biopsy if you have an active infection
- Not eating or drinking for at least eight hours before the procedure
What’s the Procedure for a Kidney Biopsy?
You’ll need to arrive early on the day of your procedure.
There are a few different ways to perform a kidney biopsy. Depending on the type of procedure, you’ll get either local or general anesthesia. Local anesthesia will help with the pain, but you’ll still be awake. Or, if the doctor wants to use general anesthesia, you’ll be entirely asleep.
The types of kidney biopsy include:
- Percutaneous. This is one of the most common procedures for a biopsy. The doctor inserts a special biopsy needle through your skin and guides it to your kidney with the help of an ultrasound or sonogram. You will need to stay still and hold your breath while the needle is moving within your body. Sometimes doctors use multiple needles to gather more than one sample at a time. Once they collect the tissues, the doctor carefully removes the needles and places a bandage over the opening. This version usually takes about an hour to complete.
- Laparoscopic. This procedure involves making two small cuts on your back. Then your surgeon inserts the tools needed to see inside your body and remove the kidney tissue. They then close the two small cuts and cover them with bandages.
- Transjugular. This is the most uncommon method of taking a kidney biopsy. With this procedure, your surgeon opens a small hole in your neck and inserts a catheter and needle into a large vein called the jugular. Then the surgeon guides the combination down through your body and to your kidney. They remove the samples through the same opening in your jugular.
- Open. Doctors usually do this when your kidney is already exposed due to another kind of surgery. It involves creating a cut in your flesh that allows your surgeon to directly access your kidney and take a sample. The specifics depend on the other procedures that are going on at the same time.
What Are the Complications of a Kidney Biopsy?
Complications from this procedure are very rare. The most common one is severe bleeding. You may need a blood transfusion or a separate procedure to fix a damaged blood vessel if your bleeding begins during the surgery. There’s also a very small chance that you could develop an infection at the biopsy site. In general, the risk of experiencing a complication during a kidney biopsy is only around 1%.
What Should You Expect After a Kidney Biopsy?
After your biopsy, you’ll have to take it easy and give the site time to heal. You may have some pain around the biopsy site.
You may need to stay in the hospital overnight. This way, your medical team can monitor your blood pressure and pulse. They may also perform blood tests to check on your recovery.
You may have pink or cloudy urine for 24 to 48 hours after the biopsy, but this should clear up on its own. Luckily, you’ll be able to resume your normal diet shortly after the surgery.
You’ll need to avoid strenuous physical activities for about two weeks after this procedure. Otherwise, your entry site may open back up. This includes:
- Heavy lifting
- Bouncing activities, like running and horseback riding
- Contact sports
There’s a slight chance that you’ll experience emergency symptoms at some point after your surgery. These include:
- An inability to urinate
- Feeling faint or dizzy
- Swelling, extreme pain, or excessive bleeding at the biopsy site
You need to contact your doctor immediately if you experience any of these symptoms while recovering from your biopsy. Don’t hesitate to contact your doctor if you have any questions or concerns at any point before or after this procedure.