What Is a Kidney Biopsy?

A kidney biopsy, also called renal biopsy, is a medical procedure which involves taking a sample tissue of the kidney for laboratory analysis. This procedure helps your doctor know the type of disease on your kidney, how severe the disease is and the best treatment option. A kidney biopsy is also used to monitor how effective is kidney treatments and also see if any complications arise in case of a kidney transplant.

Kidney biopsy tissue samples may be taken by use of two different methods as discussed below:

• Open Biopsy - In this procedure, the tissue sample is extracted directly from the kidney during surgery. The kidney tissue sample is then sent to a pathologist who examines it under a microscope to check for any signs of disease.
• Percutaneous Biopsy- It involves placement of a thin needle through kidney skin to extract a tissue sample. This process is guided to the right place of the kidney by ultrasound.

Why do I need a kidney biopsy?

Some of the kidney diseases and conditions can be identified with the help of simple blood tests, urine tests, special X-rays, physical examination and ultrasound rather than a biopsy. However, some patients who have a kidney transplant or some types of kidney disease and their kidneys are not functioning normally may have a kidney biopsy for correct diagnosis.

The main reasons why you should have a kidney biopsy include:

• Presence of either blood or protein in the urine
• Glomerular disease and nephrotic syndrome which occurs as a result of damaged kidney filtering units
• In case your doctor get abnormal or misleading blood test results for your kidney
• Chronic or acute kidney disease with unknown cause
• In case of a kidney tumor
• Any unusual and special kidney conditions
• In case some treatments are causing harm to your kidneys
• To see how much permanent damage has occurred to your kidneys
• In case a certain disease is getting worse after treatment and has also failed to cure but is slowed down by other special therapies
• To see why a transplanted kidney is not functioning well. This helps your doctor plan for further treatment

Your doctor will always explain to you why kidney biopsy is recommended for you. You should also know why this procedure is necessary, its side effects and benefits. You will also be required to sign a consent form to make sure that you understand the risks and side effects of kidney biopsy. You need to be sure that you have understood the risks of this procedure before signing the permission form.

How to prepare for Kidney Biopsy

You are required not to take aspirin and other over-the-counter medications such as ibuprofen, nuprin, Advil and naproxen two weeks before kidney biopsy. Any other medication that may cause thinning of your blood should be avoided. These drugs may change the normal way your blood clots causing excessive bleeding.  For the reason of blood thinning, you should also avoid taking some diet supplements such as fish oil.

Urine and blood samples may also be performed by your doctor before kidney biopsy to make sure that you are free from infections and other diseases. You are also required not to eat or drink anything 8 hours before kidney biopsy.

How is Kidney Biopsy Done?

This procedure is always done in a hospital. You will also be required to stay in the hospital a night after the procedure for your nurses to monitor any problems. During the procedure, you may be awake under a local anesthesia or unconscious under a general anesthesia. If the biopsy is being performed for a transplanted kidney, you will be required to lie on your back. Otherwise, you should lay your face lying down and place a pillow under your rib cage.

Percutaneous Biopsy
During this procedure, your kidney is located by use of X-ray images or sonogram (special ultrasound). Sometimes, your doctor may inject a special dye into your veins that will help your doctor locate the kidney and the main blood vessels. Once the doctor locates the site for biopsy, the skin is marked and then cleaned for a biopsy needle to be inserted.

You will be required to take a deep breath and then hold it as the doctor inserts a biopsy needle. You may be required to hold your breath for about 45 seconds. At times, 2 needles may be required to get enough sample tissue for this procedure. When enough samples have been extracted, the needle is removed and then, the area is covered with a bandage. The procedure takes approximately one hour, but sometimes takes longer.

Open Biopsy

Your doctor may recommend open biopsy in case you have a history of excessive bleeding after a cut. An open biopsy is performed when your surgeon can see the kidney to help get a good tissue sample for analysis. During this procedure, you will receive a general anesthesia which means that you will be unconscious during the whole procedure. Your surgeon will therefore make an incision and then surgically extract a tissue sample from the kidneys.

Open biopsy can also be performed laparoscopically. This is where your doctor makes a small incision and then uses it to insert a laparoscope to perform a biopsy. A laparoscope is a thin, lighted tube with a camera at the end which is connected to a computer. The camera sends images of your kidney to a video monitor which is used by your doctor to take a tissue sample of your kidney for close examination.

Risks of Kidney Biopsy

Development of an infection such as bacterial infection after kidney biopsy can be a serious risk. You should always be alert and watch out for symptoms that may indicate presence of an infection after kidney biopsy.

You should therefore contact your doctor in case you have:

• A feeling of faint of weakness
• A problem when urinating
• Fever or chills
• An intensifying pain at the site of biopsy
• Blood clots for more than 24 hours after the procedure

In addition to bacterial infection, kidney biopsy can expose you to a risk of internal damage of the kidney and the neighboring tissues.

Bottom Line

A kidney biopsy can be a perfect approach to help your doctor get valuable information that helps him or her diagnose any kidney abnormalities and decide suitable treatment measures. The whole procedure may seem scary, but it is always pain free and exposes you to less risks.