What is Kidney Biopsy? How is it Done, Risks and Results

Kidney biopsy is an important tool for diagnosing many kidney diseases. Tissue samples are taken from the kidney to be examined under a microscope. Although these procedures, which are performed under expert supervision, are generally considered safe, they carry some minimal risks. These risks include bleeding, pain, and infection. The samples taken during the biopsy are examined and reported by pathologists. Therefore, results can be shared with the patient and their relatives within a few days.

What is Kidney Biopsy and When is it Applied?

Some kidney disorders can be diagnosed using imaging methods such as blood and urine tests, ultrasound, and X-rays, but advanced diagnostic methods should be used for conditions that cannot be diagnosed with these procedures. Kidney biopsy is among the advanced diagnostic methods. A kidney biopsy is a medical procedure in which one or more small tissue samples are taken from the kidneys. These samples are analyzed under special microscopes, and the results are reported. The rate of application in adults is higher than in children. The kidney biopsy procedure can be applied in the following situations:

• Presence of unwanted structures such as blood (hematuria) and protein (proteinuria) in urine,
• Abnormal urine and blood test results (abnormally high waste in the blood may indicate that the kidneys are not functioning adequately),
• Acute (short-term) or chronic (long-term) kidney diseases of unknown cause,
• Nephrotic syndrome and glomerular disease (develops when the mechanism responsible for filtering in the kidney is damaged),
• To examine the effect of a treatment applied to the kidneys,
• If there is a loss of function in the kidneys,
• Diagnosis of protein leakage,
• To check whether there is permanent damage to the kidneys,
• To determine whether the tissues developing in the kidney are cancerous,
• To investigate whether any medication or toxic substance has harmed the kidneys,
• After a kidney transplant,
• If there is kidney transplant rejection and dysfunction,
• If there are connective tissue diseases such as systemic lupus erythematosus,
• Biopsy can be planned if there are primary and secondary kidney masses.

How is Kidney Biopsy Performed and What Methods are Used During the Procedure?

Kidney biopsy is usually performed percutaneously (a minimally invasive procedure that accesses the target tissue through the skin) from the patient’s back. The kidney biopsy needle is usually guided using ultrasound. The procedure is mostly performed by nephrologists, who are doctors specialized in kidney diseases. Depending on the cause of the disorder, urologists may also perform the biopsy procedure. The types of kidney biopsy vary according to the procedures applied during the biopsy. The following information can be provided about these methods and types of kidney biopsy:

• Percutaneous Kidney Biopsy: The healthcare professional inserts a thin biopsy needle through the skin towards the kidney to take a sample from the kidney tissue. Generally, all procedures are performed this way. The patient must lie face down with a firm pillow or sandbag under their body. Depending on the person’s condition (pregnancy, obesity, transplant, etc.), different positions may be required. The area where the needle will enter the skin is marked, cleaned, and numbed locally. Ultrasound is generally used to guide the biopsy needle. The needle may be inserted multiple times. After this procedure, stitches are not needed, and the area can be covered with a bandage.
• Laparoscopic Kidney Biopsy: The healthcare professional makes two small incisions in the patient’s back and places special devices to visualize the kidneys and collect tissue samples. This procedure is usually performed under general anesthesia.
• Transjugular Kidney Biopsy: A catheter and needle are placed in the jugular vein located in the neck. The biopsy needle passes through the vessels to reach the kidney and collect tissue samples. This method is used less frequently than the laparoscopic method.
• Open Kidney Biopsy: This is a procedure in which the healthcare professional takes tissue directly from the kidney through an invasive approach. This procedure, performed under general anesthesia, is rarely preferred.

What Preparations Should the Patient Make Before Kidney Biopsy?

The doctor of the patient who will undergo a kidney biopsy will provide comprehensive information about the preparations that need to be made before the procedure. At this stage, it is very important for the patient and their relatives to ask all questions that come to mind to the doctor and get answers. The patient or their relatives may sign a consent form stating that they agree to the procedure. This form should be read carefully, and unclear statements should be clarified by asking questions. To understand whether the patient’s health condition is suitable for biopsy, some physical examinations, blood tests, and other diagnostic tests may be performed. The patient must share their pregnancy status or any possibility of it with their doctor before the procedure.

If the patient has any sensitivity or allergy to any medication, latex, bandages, or anesthesia, this should be shared with the doctor. All medications, vitamins, and supplements taken should be reported to the doctor. If the patient has a bleeding disorder or is using anticoagulant medications, this should also be known to the doctor, as it may be necessary to pause these blood-thinning medications before the procedure. Doctors or other healthcare professionals will share a list of foods and drinks that the patient should not consume before the biopsy. It is very important to follow the instructions provided here.

What Risks and Complications May Be Encountered During and After Kidney Biopsy?

Although kidney biopsy is a procedure with minimal risks and complications, some unwanted situations may develop during or after the procedure. The most common complication is bleeding at the biopsy site. Mild bleeding is common after the procedure, but in some patients, bleeding may be severe enough to require a blood transfusion. Pain and infection at the biopsy site are also among the risks of kidney biopsy. Rarely, damage to nearby organs or structures may occur. If one or more of the complications listed below develop after the biopsy procedure, immediate medical assistance should be sought:

• Inability to urinate, excessive need to go to the toilet, or pain-burning sensation while urinating,
• Presence of dark red or brown blood clots in urine,
• Severe pain, redness, bleeding, swelling, and discharge at the biopsy site,
• Fever and chills,
• Arteriovenous fistula,
• Fainting and dizziness.

How Long Does it Take for Kidney Biopsy Results to Come Out and How are These Results Evaluated?

After the biopsy, the kidney tissue is sent to a laboratory to be examined by a pathologist. Tissue samples are examined in detail under a microscope. Pathologists focus on abnormalities in cell structure, signs of inflammation, abnormalities in blood vessels, wear, and scar tissue formation. After the results are obtained, the reporting process begins. This entire process may take about a week, depending on the laboratory’s workload. The prepared report is delivered to the doctor. The doctor makes a diagnosis and creates a treatment plan based on the evaluations of various parameters.

Frequently Asked Questions

If you have concerns about your kidney health or your doctor has recommended a kidney biopsy, you can get detailed information by making an appointment with our specialists here. For early diagnosis and proper treatment, please contact us.