The main complication of renal biopsy is bleeding. If there is any blood coagulation problem, renal biopsy cannot be safely done as there may be uncontrolled bleeding. It is therefore mandatory that patient’s coagulation profile be checked by various blood tests before renal biopsy. 

Conditions that can cause bleeding tendencies are certain blood disease, the consumptions of drugs like Aspirin or other non-steroidal anti-inflammatory drugs, which must be stopped at least five days prior to renal biopsy. 

Other contraindications of renal biopsy include severe or uncontrolled hypertension, anaemia, single kidney and cystic kidneys. 

While blood-stained urine is a very common occurrence after renal biopsy, it should clear up within one day. The presence of blood clots or heavily blood-stained urine may signify more severe bleeding that required immediate attention. Occasionally, transient fever is observed after biopsy. 

The procedure is done with patient sedated under monitoring. Biopsy is done through a 2 to 3mm skin incision at the back over the loin area. A specialised needle is introduced under ultrasound guidance, directed at the lower end of the kidney where two to three tiny bites of renal tissues were taken. The renal tissues obtained are then prepared and sent for histological studies. The whole procedure usually takes about 20 to 30 minutes and patient usually awakes soon after the procedure. 

The doctor first discusses with the patient or parents on the indications of renal biopsy and a written informed consent is obtained. 

Next, the patient must be deemed well and fit for the procedure and will be advised to be admitted for a total of two days. Renal biopsy is usually done electively as a non-urgent procedure. The patient will be admitted one day before the biopsy. Blood coagulation status and blood matching will be checked to make sure there is replacement blood on standby in the event a blood transfusion is required. 

Fasting is required for at least six hours before the procedure. 

Normal eating and drinking can be resumed when the patient is awake. Rest by lying flat on the back to press on the wound site to stop bleeding if any. The patient will be monitored overnight for any signs of bleeding. The patient will be reviewed and discharged the next day. Refrain from physical exercise for up to six months. The discharge advice includes returning to hospital if there is heavily blood-stained urine especially in the presence of blood clots, pain over biopsy site, fever, abdominal pain and vomiting. 

Renal biopsy is a very informative and very useful diagnostic procedure. It is a very safe procedure. Success of the procedure is almost 100% and careful preparation ensures less than 1% risk of significant side effects.