Percutaneous nephrolithotomy (PCNL) is a minimally-invasive means of removal of large or complex kidney stones through a small incision (less than 1 cm).
This surgery is typically reserved for stones that are too large to be removed by other means. A small telescope device called a nephroscope is inserted directly into the kidney through the flank, and special instruments are used to fragment and extract stones.
When to ask a Urologist about PCNL
You should speak with a Urologist about PCNL if you have a total stone burden larger than 2 cm in the kidney or upper ureter (tube that drains the kidney). It is sometimes used for stones that are 1.5 cm if located in the lower part of the kidney.
Typically covered by most insurances (although coinsurance and deductibles may apply). Coverage will be verified prior to proceeding. If you do not have insurance, our office will be able to give you an out-of-pocket cost estimate.
For renal stones with greater than 2 cm total stone burden, PCNL is first-line management. In this setting the stone-free rate is higher with PCNL than URS (94% vs 75%) and requires fewer procedures. It is also the most effective treatment for stones that are 1.5 cm and located in the lower part of the kidney.
Possible Side Effects
PCNL does involve a higher risk of complications than other stone surgeries (ESWL and ureteroscopy). Possible risks include postoperative fever (20%), need for blood transfusion (5%), blood stream infection (3%), need for kidney embolization (minimally invasive method to stop kidney bleeding) (1%), and injury to surrounding organs (1%). Additional risks are similar to any surgical procedure and include pain as well as the risks of general anesthesia.
Alternatives to PCNL may include surgical stone treatment with ureteroscopy or ESWL though either of these approaches may require multiple surgeries due to the large stone size. Asymptomatic stones may be observed though this approach may risk renal insufficiency and recurrent infection. A final alternative is open or robotic surgery to remove the stone.
What to do to Prepare for Surgery
You will receive detailed instructions from the surgical schedulers regarding any necessary testing or appointments prior to surgery. In general, you should temporarily stop blood-thinning medications prior to surgery (when to stop depends on the type of blood thinner). Prescription blood-thinning medications should be stopped following clearance from the doctors that prescribed them though other medications that thin the blood including fish oil and pain relievers such as ibuprofen should be stopped as well.
On the day before surgery, you will receive a phone call alerting you to the time that you should arrive.
You should not eat or drink anything after midnight on the day of surgery, but you may take approved home medications in the morning before surgery with a small sip of water.
What to Expect after Surgery
PCNL typically requires an overnight hospitalization for observation. Patients will wake up with a catheter in place to drain their bladder and may have an additional temporary external drainage tube exiting their side called a nephrostomy tube. The urine is usually bloody similar to fruit punch. The catheter and the nephrostomy (if present) are typically removed prior to discharge from the hospital. A temporary internal stent between the kidney and bladder is often placed at the time of surgery to help with healing of the kidney. In some patients, this stent may lead to frequency and urgency of urination, blood in the urine, and flank discomfort. The internal stent is removed in the office during a follow-up visit.