In some cases, the only way to diagnose kidney conditions is for a kidney specialist, called a pediatric nephrologist, to look at the kidney tissue through a microscope. The pediatric nephrologist obtains a tiny piece of kidney by performing a kidney biopsy (also called a renal biopsy; renal means ‘kidney’ in Latin). Most kidney diseases affect both kidneys in the same way, so the biopsy only needs to be done on one kidney.
Kidney biopsies are not always needed to diagnose a condition affecting the kidneys. If a biopsy is needed, it will be performed by an experienced radiology expert who is used to biopsying many organs.
What to expect during a kidney biopsy
Preparing for a biopsy
On the day of your child’s biopsy, he or she may have clear liquids only until 8 a.m., and should not eat or drink anything after 8 a.m. You will go to the outpatient laboratory around 10 a.m., where tests your child will receive a routine blood test. Sometimes other tests may be done at the same time.
After you have your tests done, you will come to the Kidney Center and a member of the staff will take you to the surgery area, where a team of doctors and nurses check your child in by taking their medical history and doing a physical examination. The nurse will follow the nephrologist’s orders to get your child ready for the biopsy, which usually happens around 2 p.m. in the Radiology Department. The nurse will put some numbing cream on your child’s back in the area where the biopsy is done. A doctor will have a parent or legal guardian sign a consent form for the biopsy, after making sure it is understood what a biopsy is and what risks there may be.
About the procedure
This kind of biopsy is not an operation, but children do receive anesthesia to induce sleep and lessen any pain associated with the biopsy. One medicine is given by a shot to numb the area where the biopsy will be performed. The other medicines are given through an IV, which is a small tube placed into the vein. It does not hurt to have medicine given through the IV.
Careful checks on breathing, oxygen, blood pressure and pulse are done during the biopsy and for hours afterward. In Radiology, an ultrasound is used to locate the kidneys and find the spot to put the special needles used for biopsies. An ultrasound does not hurt. By the time your child is ready to have the biopsy, he or she won’t feel any pain or even remember the procedure. The trip to and from Radiology, including the biopsy, takes about an hour. The biopsy itself takes less than fifteen minutes.
After a biopsy
After the biopsy, eating and drinking is allowed, but staying in bed and following the orders of doctors and nurses is very important. The IV will stay in until it is safe to take it out. If there are no complications, your child can go home that same evening.
For one week after your biopsy, it is important for your child to not participate in contact sports such as football, horseback riding or trampoline. Normal everyday things are okay, and your child can return to school. If your child experiences discomfort in his or her back, they can take some acetaminophen (Tylenol).
The cut in the skin at the biopsy site will be about ¼ inch long and does not require any special care. If any concerns arise, such as increasing back or abdominal pain or increasing blood in your child’s urine, let your family doctor know. When the results of the kidney biopsy are known, your child’s nephrologist will discuss them with you.