Percutaneous nephrolithotomy or nephrolithotripsy for kidney stones (PCNL)
Percutaneous nephrolithotomy, or PCNL, is a procedure for removing medium-sized or larger renal calculi (kidney stones) from the patient's urinary tract by means of an nephroscope passed into the kidney through a track created in the patient's back. The term "percutaneous" means that the procedure is done through the skin.
A standard percutaneous nephrolithotomy is performed under general anesthesia and usually takes about three to four hours to complete. After the patient has been anesthetized, the surgeon makes a small incision, about 0.5 in (1.3 cm) in length in the patient's back on the side overlying the affected kidney. The surgeon then creates a track from the skin surface into the kidney and enlarges the track using a series of Teflon dilators or bougies. A sheath is passed over the last dilator to hold the track open.
After the track has been enlarged, the surgeon inserts a nephroscope, which is an instrument with a fiberoptic light source and two additional channels for viewing the inside of the kidney and irrigating (washing out) the area. The surgeon may use a device with a basket on the end to grasp and remove smaller kidney stones directly. Larger stones are broken up with an ultrasonic or electrohydraulic probe, or a holmium laser lithotriptor. The holmium laser has the advantage of being usable on all types of calculi.
A catheter is placed to drain the urinary system through the bladder and a nephrostomy tube is placed in the incision in the back to carry fluid from the kidney into a drainage bag. The catheter is removed after 24 hours. The nephrostomy tube is usually removed while the patient is still in the hospital but may be left in after the patient is discharged. More than 500 PCNL performed yearly at labbafinejad hospital.
Alternatives include observation, multiple ESWL, ureteroscopy, and open surgical procedures. Observation is not recommended due to increased likelihood of renal damage, ESWL and ureteroscopy is not recommended since there is a likelihood of multiple procedures and decreased success rate, open surgery is not the first choice due to the invasiveness of the procedure and prolonged recuperation time, however, has an equal to better success rate than the PNL.
Most hospitals require patients to have the following tests before a PCNL: a complete physical examination; complete blood count; an electrocardiogram (EKG); a comprehensive set of metabolic tests; a urine test; and tests that measure the speed of blood clotting.
Aspirin and arthritis medications should be discontinued seven to 10 days before a PCNL because they thin the blood and affect clotting time. Some surgeons ask patients to take a laxative the day before surgery to minimize the risk of constipation during the first few days of recovery.
The patient is asked to drink only clear fluids (chicken or beef broth, clear fruit juices, or water) for 24 hours prior to surgery, with nothing by mouth after midnight before the procedure.
What to Expect After Treatment
You will be in the hospital for at least 2 to 3 days. Most people are able to return to work within a few weeks.
- This procedure may be used to treat kidney stones that are:
- Larger than 2 cm in diameter.
- Large and caused by an infection (staghorn calculi).
- Blocking the flow of urine out of the kidney.
Many stones can now be dealt with using external shock waves, which avoids any operation at all. However, not all stones are suitable for this technique, and they need to be removed surgically. It has been decided that a percutaneous nephrolithotomy is the best way of dealing with your stone.
Percutaneous nephrolithotomy is considered a very safe procedure, designed to save you having a larger operation. There are some slight risks and possible complications involved, and although it is difficult to say exactly how often these occur, they are generally minor and do not happen very often.
There are a number of risks associated with PCNL:
- Holes (perforation) in the kidney. They usually heal without further treatment.
- Damage that affects normal kidney function.
- Inability to make a large enough track to insert the nephroscope. In this case, the procedure will be converted to open kidney surgery.
- Bleeding. Bleeding may result from injury to blood vessels within the kidney as well as from blood vessels in the area of the incision.
- Fever. Running a slight temperature (101.5°F; 38.5°C) is common for one or two days after the procedure. A high fever or a fever lasting longer than two days may indicate infection, however, and should be reported to the doctor at once.
- Fluid accumulation in the area around the incision. This complication usually results from irrigation of the affected area of the kidney during the procedure.
- Formation of an arteriovenous fistula. An arteriovenous fistula is a connection between an artery and a vein in which blood flows directly from the artery into the vein.
- Need for retreatment. In general, PCNL has a higher success rate of stone removal than extracorporeal shock wave lithotripsy (ESWL). PCNL is considered particularly effective for removing stones larger than 1 cm in staghorn calculi; and stones that have remained in the body longer than four weeks. Retreatment is occasionally necessary, however, in cases involving very large stones.
- Injury to surrounding organs. In rare cases, PCNL has resulted in damage to the spleen, liver, lung, pancreas, or gallbladder.
PCNL has a high rate of success for stone removal, over 98% for stones that remain in the kidney and 88% for stones that pass into the ureter.