PERCUTANEOUS NEPHROLITHOTOMY (PCNL) and MINI-PCNL

• Percutaneous nephrolithotomy (PCNL) is a minimally-invasive procedure to remove stones from the kidney by a small puncture wound (up to about 1 cm) through the skin.
• It is most suitable to remove stones of more than 2 cm in size and which are present near the pelvic region.
• It is usually done under general anesthesia or spinal anesthesia.
• These procedures are treatments for kidney stones that are used in patients with large or irregularly shaped kidney stones, people with infections, stones that have not been broken up enough by extracorporeal shockwave lithotripsy (ESWL) or those who are not candidates for another common stone treatment, ureteroscopy. Stones that are bigger than 2 cm (the size of a marble) require this procedure.

This is what the words mean:

• Percutaneous means through the skin
• Nephrolithotomy is a combination of the word roots nephro- (kidney), litho-(stone) and -tomy (removal)
• Nephrolithotripsy is a combination of the word roots nephro- (kidney), litho (stone), and -tripsy (crushed)

PROCEDURE

• A retrograde pyelogram is done to locate the stone in the kidney. With a small 1 centimeter incision in the loin, the percutaneous nephrolithotomy (PCN) needle is passed into the pelvis of the kidney.
• The position of the needle is confirmed by fluoroscopy.
• A guide wire is passed through the needle into the pelvis. The needle is then withdrawn with the guide wire still inside the pelvis. Over the guide wire the dilators are passed and a working sheath is introduced.
• A nephroscope is then passed inside and small stones taken out. In case the stone is big it may first have to be crushed using ultrasound probes and then the stone fragments removed.
• The most difficult portion of the procedure is creating the tract between the kidney and the flank skin. Most of the time this is achieved by advancing a needle from the flank skin into the kidney, known as the 'antegrade' technique.
• A 'retrograde' technique has recently been updated wherein a thin wire is passed from inside the kidney to outside the flank with the aid of a flexible ureteroscope. This technique may reduce radiation exposure for patient and urologist.
• Both procedures involve entering the kidney through a small incision in the back.
• Once the urologist gets to the kidney, a nephroscope (a miniature fiberoptic camera) and other small instruments are threaded in through the hole. lf the stone is removed through the tube, it is called nephrolithotomy.
• lf the stone is broken up and then removed, it is called nephrolithotripsy. The urologist can see the stone, use high frequency sound waves to break up the stone, and "vacuum" up the dust using a suction machine.

Will I be hospitalized for this procedure?

Yes. This requires a general anesthesia. You will need a short (2 or 3 day) hospitalization. You may be off work for a week or so. Depending on the position of the stone, the procedure is completed in 20 to 45 minutes. The goal is to take out all of the stones so that none are left to pass through the urinary tract.

What are the risks?

The following complications may take place:

• Even minimally invasive surgeries, like percutaneous nephrolithotomy or nephrolithotripsy, carry risks of infection, bleeding, and other complications.
• The procedure creates a hole in the kidney that usually heals without other treatment. Operations on the abdomen carry a small risk of injury to other nearby organs, such as the bowel, the ureter, the liver or the bladder.
• Injury to the colon
• Injury to the lungs
• Injury to the renal blood vessels
• Urinary leak may persist for a few days
• Infection and sepsis
• Hydrothorax if PCNL is done through 11th intercostal space
• Bleeding
• Death

ls it my only option?

When stones are very large (more than 2 cm) or in a location that does not allow effective extracorporeal shockwave lithotripsy or ureteroscopy, percutaneous stone removal may be needed. Any operation on the kidney carries a relatively rare long term risk of high blood pressure or reduced kidney function later in life. You should talk with your urologist about this. percutaneous stone removal may be needed. lt often avoids the need for more invasive open surgery, which is another option for these stones, but that is only very rarely needed.

What are the advantages and disadvantages?

One advantage of this surgery is that it is the most effective technique for making sure a patient is stone-free. Most patients leave the hospital stone free. Occasionally, though, another procedure will be needed to remove a stone.

Even though it involves an incision, it is less invasive than a full open surgery to treat the kidney stone. Because it is among the more difficult surgeries, it is performed by urologists with specialized training. Urologists and radiologists may work together on these surgeries.

Notes and References

• Dr.Rajgopal Shenoy K (2006). Manipal Manual of Surgery - Second Edition, p.619. CBS Publishers & Distributors, New Delhi.
• Wynberg JB. Flexible ureteroscopy-directed retrograde nephrostomy for percutaneous nephrolithotomy: description of a technique. 2012 Oct;26(10):1268-74. doi:10.1089/end.2012.0160. PMID 22563900.
• • Ashish V. Patil. A Novel 5-Part Percutaneous Access Needle With Glidewire Technique (5-PANG) for Percutaneous Nephrolithotomy: Our Initial Experience. Urology. 2010 May;75(5):1206–1208. doi:10.1016/j.urology.2009.11.027. PMID 20138340.