Diagnosis of Kidney Diseases

Kidney biopsy

Kidney biopsy is an important test useful in the diagnosis of certain kidney diseases such as glomerulonephritis, certain tubulointerstitial diseases, etc.

During a kidney biopsy, a small piece of kidney tissue is removed through a needle and examined under a microscope. Kidney biopsy is performed to diagnose the exact nature of certain kidney diseases, e.g. glomerulonephritis and certain tubulointerstitial diseases, etc.

In certain kidney diseases even a detailed history, physical examination and routine tests are unable to establish proper diagnosis. In such patients, a kidney biopsy may provide additional information, which can establish the correct diagnosis.

The kidney biopsy establishes specific diagnosis of certain unexplained kidney diseases, e.g. glomerulonephritis and certain tubulointerstitial diseases, etc. With this information, the nephrologist is able to plan effective treatment strategy and guide patients and their family about the severity and course of the disease.

The most common method is via a percutaneous needle biopsy (usually performed in the radiology suite), in which a hollow needle is passed through the skin into the kidney. Another rarely used method is open biopsy which requires surgery (performed in the operating room).

• The patient is admitted in hospital and his consent is obtained.
• Prior to biopsy it is ensured that blood pressure and blood tests on blood clotting are within normal. Medications used for the prevention of blood clotting (e.g. aspirin and clopidrogel) is recommended to be discontinued for at least 1- 2 weeks prior to biopsy.

• Ultrasound or CT scan is done to know the position of kidneys and to determine exact biopsy site.
• The patient is asked to lie face down – on his/her stomach with the abdomen supported by a pillow or towel. The patient is fully awake during the procedure. In small children the kidney biopsy is done under general anesthesia, so the child is not awake.
• After proper cleaning of the skin, the biopsy site is numbed with local anesthesia to minimize discomfort and pain.
• With the use of a hollow biopsy needle, 2 or 3 small thread like pieces are obtained from the kidney. These specimens are then sent to the pathologist for histopathology examination.
• After the biopsy, pressure is applied to the biopsy site to prevent bleeding. The patient is put on complete bed rest for 6-12 hours and usually discharged the following day.
• The patient is advised to avoid heavy work or exercise for at least 2-4 weeks after the biopsy procedure.

Like any surgical procedure, complications can occur in a few patients after kidney biopsy. Mild pain or discomfort over the puncture site and passing of reddish urine once or twice is not uncommon, but it usually stops on its own. In rare cases where bleeding continues, blood transfusion may be required. In extreme and very rare circumstances where by intractable severe bleeding persists emergency removal of kidney by surgery may become necessary.

Sometimes kidney tissue obtained may not be adequate for diagnosis (about 1 in 20). Repeat biopsy may be needed in such cases.