Percutaneous Nephrolithotomy (PCNL)

Percutaneous Nephrolithotomy (PCNL)

Watch Video on Percutaneous Nephrolithotomy (PCNL) Operation

This endoscopic procedure is for large kidney stones > 2 cm size via a keyhole tract into the kidney. Such stones are difficult to break with shockwave treatment (ESWL). ESWL is also not suitable because such big stone is not only harder to break, but can also block the kidney when the large-volume stone pieces pass down the ureter.

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 provide a "road map" of 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 is used to break the stones and remove the pieces. At the end of the procedure, a nephrostomy tube is left in the kidney to drain urine, blood and small stone fragments. The nephrostomy tube is removed only 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 stones can be broken by ESWL. After removal of this tube, leakage of urine can be expected up to 2 days while waiting for the hole in the kidney to close. The operation takes about 2 to 3 hrs and the hospital stay is generally 3 to 4 days. The success rate (defined as residual fragment < 3 mm) for PCNL is 95%.

Complications include:

  • excess bleeding during surgery requiring blood transfusion.
  • bloody urine. This is expected to last up to 2 weeks. If excessive, an abnormal artery to vein connection (called a-v malformation) may have occurred and requires readmission to hospital for embolisation to be performed by the interventional radiologist.
  • may need readmission to hospital for urgent radiological intervention because of excess bleeding from
  • urine leak. This occurs through the puncture wound at the back. However, it should dry up by the 2nd day after removing the nephrostomy tube.
  • hydrothorax (fluid in lung cavity). This can occur if the puncture track goes through the lung lining. It will cause breathlessness and can be seen on chest xray. A drainage tube needs to be inserted if this complication occurs.

Desired outcomes:

  • no blood transfusion ( < 5% risk )
  • no a-v malformation post-op ( 3% chance )
  • no hydrothorax
  • stone-free rate > 95 %