Percutaneous Nephrolithotomy (PCNL)

Process of PCNL surgery

This surgery uses a keyhole approach to break large kidney stones > 2 cm size. Shockwave treatment (ESWL) is not suitable because such big stones are not only harder to break, but can also block the ureter when the stone fragments pass down.

Dr Chin doing PCNL surgery
Stone being broken at PCNL

Under general anaesthesia and xray guidance, a catheter is placed into the kidney via the bladder using a cystoscope. Through this tube, xray dye is injected to outline the kidney system to plan the best approach for the puncture track. A track is established through a series of dilators to allow a nephroscope to be inserted. Through this nephroscope, an ultrasonic, pneumatic probe or laser is used to break the stones and remove the pieces. A nephrostomy tube is left in the kidney at the end of the surgery to drain urine, blood and small stone fragments. This tube is removed after the bleeding has settled. A check xray is done on the 2nd day to look for any significant residual stone fragments. If so, a completion session can be done before removing this tube. Alternatively, this remnant stone can be managed by ESWL. Some leakage of urine can be expected up to 2 days after the nephrostomy tube is removed. The operation takes 2 to 3 hrs and the hospital stay is 3 to 4 days. The success rate (defined as residual fragment < 3 mm) for PCNL is > 95%.

Complications include:

  • bloody urine.This can last up to 2 weeks. In 3% of cases, an abnormal artery to vein connection (called a-v malformation) may develop. This causes excess bleeding to need readmission to hospital for urgent radiological intervention.
  • urine leak. This occurs through the puncture wound at the back. However, it should dry up over the next few days.
  • hydrothoraxThis is a rare complication due to accidental puncture through the lung cavity during the track creation. Chest xray will confirm this and the remedial action is to insert a chest tube for a few days.