Kidney Biopsy Test and Procedure
Overview
A kidney biopsy is a medical test in which a doctor takes a small piece of kidney tissue. The doctor checks this tissue sample under a microscope to find signs of kidney disease or damage. Doctors may suggest this test if they think there is a problem with the kidneys or if they want to monitor how well treatment is working.
Doctors sometimes use kidney biopsies after a kidney transplant to find out why the new organ is not working as it should. The most common way to collect the tissue uses a slender needle that goes through the skin. An imaging tool, such as an ultrasound, helps the doctor guide the needle into the correct spot.
Key Points:
- Checks for kidney disease or injury.
- Essential for evaluating transplant candidates.
- Employs a needle and imaging technology to ensure precision.
Reasons for Performing a Kidney Biopsy
A kidney biopsy is often suggested when certain signs point to kidney trouble that other tests can’t fully explain. This procedure helps doctors check what kind of kidney disease someone has and see how badly the kidney is affected. Common reasons for a kidney biopsy include:
- Checking for an unknown kidney problem.
- Guiding treatment decisions based on specific kidney changes.
- Finding out how fast kidney disease is getting worse.
- Measuring damage caused by kidney issues or other diseases.
- Seeing if kidney treatments are working.
- Examining a transplanted kidney or finding out why a new kidney is not working as well as expected.
Doctors may consider a biopsy if these findings are present:
| Finding | What It Shows |
|---|---|
| Blood in urine | Possible kidney source |
| Extra protein | Kidney leaking abnormal levels |
| Poor function | High waste in blood |
Decisions about having a kidney biopsy also depend on a person’s test results, how they feel, and other health conditions. Not everyone with these symptoms will need this test.
Possible Complications
Doctors consider a kidney biopsy a safe test, but some risks exist. Bleeding is the most common problem and may appear as blood in the urine. This usually clears up within a few days. In rare cases, the bleeding can be severe enough to require a blood transfusion or even surgery.
Pain at the needle insertion site is also common. Most people feel soreness for a few hours, but it typically does not last long. Another possible complication is an arteriovenous fistula, which happens when a connection forms between a vein and an artery. Most of the time, this causes no problems and heals on its own.
Other rare issues include infection, especially if a hematoma (a collection of blood) around the kidney becomes infected. Doctors may treat this with antibiotics or surgery. A large hematoma can also lead to high blood pressure in some cases. The following list shows some possible risks:
- Bleeding
- Pain
- Arteriovenous fistula
- Infection
- High blood pressure
Steps to Get Ready
Checking Your Current Medications
Patients need to share a list of all their medicines, including any over-the-counter drugs, vitamins, or herbal supplements. Some medicines can make bleeding more likely during the biopsy. Common examples are:
- Anticoagulants
- Antiplatelet drugs
- Aspirin
- NSAIDs
- Certain supplements (for example, omega-3)
The healthcare provider will explain when to pause these medicines. Usually, these are stopped about one week before the test and restarted a week after. Patients should follow the instructions exactly as given by their healthcare team.
Lab Tests Before the Procedure
Patients give blood and urine samples before the kidney biopsy. These tests help make sure there is no infection or health issue that could cause problems during or after the procedure. Lab results guide the medical team in planning the safest approach.
What to Eat and Drink Beforehand
Most people will be told to stop eating or drinking for about eight hours before the scheduled kidney biopsy. This helps lower the risk of side effects. It is important to follow these instructions to help the test go smoothly.
Tip: Keeping a checklist of these steps can make the preparation less stressful. If unsure about any directions, contact the healthcare team for help.
What You Might Experience
While the Tissue Sample Is Taken
Before the test, a nurse places an IV in the patient’s arm. This allows sedative medicine to be given to help with comfort. The individual remains awake but may experience a sense of relaxation. The patient lies on their stomach or side to make the kidney easy to reach.
For people with a kidney transplant, lying on the back is common. An ultrasound or CT scan helps the doctor find the best spot to take the sample. A doctor marks the skin and cleans the area, then injects a local anesthetic to numb it. This numbing medicine helps reduce pain or discomfort.
The doctor makes a small cut for the needle. Using a special instrument guided by imaging, the doctor quickly takes a small piece of tissue from the kidney. At times, the doctor may ask the patient to hold their breath to keep the kidney still.
The doctor may insert the needle more than once if more tissue is needed. Some people feel a quick pressure or hear a clicking noise during the collection. When finished, the doctor removes the needle and places a bandage on the spot.
Table: Main Steps During Sample Collection
| Step | Description |
|---|---|
| Sedative and IV | Relaxation and medicine given through the vein. |
| Positioning | Lying on side, stomach, or back. |
| Imaging Guidance | Ultrasound or CT scan helps guide the doctor. |
| Local Anesthetic | Numbs the skin and deeper tissue. |
| Sample Collection | Needle removes a small tissue piece. |
| Bandaging | Protects the biopsy area. |
Other Ways Kidney Samples Are Collected
If a standard needle biopsy is not safe—such as for people with bleeding problems or only one kidney—doctors use another method called a laparoscopic biopsy.
With this method, the doctor makes a small cut and inserts a thin, tube-like camera called a laparoscope. This camera sends images to a screen so the doctor can watch closely while collecting tissue. This technique also allows for special tools to be used to take the sample safely.
What Happens Afterward
After the biopsy, the patient moves to a recovery area. Staff monitor blood pressure, pulse, and breathing closely for several hours. The patient rests quietly for about four to six hours.
Staff perform lab tests on blood and urine to check for bleeding and identify any problems. The person receives written instructions and might take pain medicine if there is soreness at the site.
Most people go home the same day, usually within 12 to 24 hours. When home, rest is important. It is usually best to avoid strenuous activity, heavy lifting, and sports for a few days. The kidney tissue goes to a medical lab. A pathologist checks it under a microscope for signs of damage, scarring, or other disease.
Common Recovery Advice
- Rest for at least 24 hours.
- Drink fluids as advised.
- Take pain medicine if needed.
- Watch for signs of trouble.
When to Contact a Doctor
- Bright red blood or clots in the urine after 24 hours
- New or severe pain at the biopsy site
- Problems with urination
- Fever higher than 100.4°F (38°C)
- Feeling dizzy or weak
Test Outcomes
Biopsy results are usually ready within a week, but in urgent cases, some findings can be available in less than 24 hours. Test results help explain the cause of kidney issues and guide future treatment steps. Typically, doctors review results with patients during a follow-up visit.
Time to Receive Results
| Situation | Approximate Timeframe |
|---|---|
| Regular cases | Up to 7 days |
| Urgent cases | Less than 24 hours possible |
