Medical Content Created by the Faculty of the
Harvard Medical School
On the day of the test, you provide a urine sample to be tested for signs of a bladder infection. If you have an infection in the urine, you need to get treatment before you are able to have the biopsy done. Your blood pressure is measured. You will have an IV (intravenous) line placed in a vein in case you need any fluid during the procedure.
You lie on your stomach with a pillow under your abdomen to support you. You then have an ultrasound, a painless test that uses sound waves to create a picture of the internal organs. Some clear jelly is squirted onto your back on both sides; then the ultrasound sensor, which resembles a microphone, is held against your back. The doctor uses the ultrasound to make sure you have two kidneys (occasionally, a person is born with just one kidney) and to locate the one that is to have a sample taken. You are asked to take a deep breath, a shallow breath, and a normal breath and to hold each one. This allows the doctor to see what type of breathing moves the kidney into a position where it is easy to biopsy.
Some numbing medicine is injected under your skin and into the muscle that the biopsy needle is to go through. The ultrasound sensor continues to show the kidney while this medicine is being injected. You will feel some brief stinging from the numbing medicine.
A special sampling needle is then pushed gently into the area that has been numbed by the medicine. The doctor pushes this needle forward until it is just at the edge of the kidney. Your doctor then releases a special spring-loaded mechanism on the needle that quickly moves the needle a short distance into and out of the kidney to collect the sample. Some patients feel some discomfort from each biopsy, but because the needle moves so quickly, this lasts only for a second. Your doctor asks you to hold a large or small breath (as you practiced earlier) when the kidney is being sampled. The needle is removed and the sample put aside for testing. A second sample is taken from the same kidney using the same technique.
A bandage is placed on your back where the needle was inserted. The doctor takes another look with the ultrasound to see that you do not have any bleeding around your kidney.