Nephrolithotomy is a surgical procedure to remove kidney stones directly from the kidney. The most common form today is percutaneous nephrolithotomy (PCNL), a minimally invasive technique where the surgeon reaches the kidney through a small incision in the back rather than a large open cut. It’s the standard treatment for kidney stones larger than 2 centimeters, roughly the size of a nickel, and for complex stones that won’t respond to less invasive options like shock wave therapy or passing naturally.
When Nephrolithotomy Is Recommended
Most small kidney stones can be treated with shock waves that break them up from outside the body, or with a thin scope passed through the urinary tract. Nephrolithotomy is reserved for situations where those approaches aren’t enough. The primary trigger is stone size: stones 2 centimeters or larger are generally best handled with PCNL, and for stones above 4 centimeters, it’s considered the clear first choice.
Beyond size, several other scenarios call for this procedure:
- Staghorn stones that branch into multiple parts of the kidney’s drainage system
- Lower pole stones that sit in a part of the kidney where fragments don’t drain well after other treatments
- Stones made of cystine, a type that resists shock wave treatment
- Abnormal kidney anatomy that makes it hard for other methods to reach or clear the stone
- Failed prior treatment, such as shock wave lithotripsy that didn’t fully break up the stone
How the Procedure Works
The word “percutaneous” means “through the skin.” During PCNL, the surgeon creates a narrow passageway from the skin on your back directly into the kidney. This tract is typically about the width of a pencil, though exact size varies depending on the technique. With imaging guidance (usually fluoroscopy or ultrasound), the surgeon places a needle into the kidney, widens the channel, and passes a rigid scope called a nephroscope through it.
Once the scope is inside the kidney, the surgeon uses one of several tools to break the stone into removable pieces. Ultrasonic devices vibrate at high frequencies to fragment the stone while simultaneously suctioning out the debris. Pneumatic tools use compressed air to hammer the stone apart without generating heat. Laser energy, most commonly from a holmium laser, can also vaporize stone material with precision. In many cases, surgeons combine these methods depending on the stone’s size and hardness. Small enough fragments get pulled out through the scope; the rest are suctioned away.
What Recovery Looks Like
Hospital stays after PCNL average about 4 days, which is notably shorter than the roughly 6 days typical of traditional open surgery. After the procedure, you’ll have some form of drainage in place to let urine flow freely while the kidney heals. Options include a thin tube exiting through the back (a nephrostomy tube), a ureteral stent placed inside the body between the kidney and bladder, or sometimes both.
How long drainage stays in varies. In straightforward cases with no complications, some centers now remove the ureteral stent the day after surgery, right before discharge. When stents are left longer, the average is about six days, with removal done in a quick office procedure. Practices vary by surgeon and by how the surgery went, so your timeline may differ. In the first week or two at home, expect some blood in your urine, mild to moderate discomfort near the incision site, and instructions to avoid heavy lifting or strenuous activity.
Success Rates
PCNL is effective at clearing stones in a single session. Studies report stone-free rates around 82 to 84% after one procedure. For comparison, open surgery achieves slightly higher clearance rates (around 92%) because the surgeon has direct access to the entire kidney, but the trade-off is a longer recovery, a bigger incision, and more time in the hospital. When PCNL doesn’t clear every fragment on the first attempt, a second-look procedure through the same tract or a supplemental shock wave session can clean up what’s left.
Potential Complications
The overall complication rate for PCNL is about 22%, but the large majority of those are minor. Around 16% of patients experience low-grade complications that resolve with straightforward management, while serious complications occur in roughly 5 to 6% of cases.
Bleeding is the most common issue, both during and after surgery. About 10% of patients need a blood transfusion, and roughly 18% notice significant blood in their urine afterward. Fever affects about 13% of patients, and urinary tract infections develop in about 5%. Urine leakage from the incision site occurs in roughly 7 to 8% of cases and typically resolves on its own as the tract heals. Rare but more serious complications include lung-related issues like fluid or air around the lung (about 1.5%), severe infection spreading to the bloodstream (1.5%), and, very rarely, bleeding severe enough to require a procedure to seal the affected blood vessel.
PCNL Compared to Open Surgery
Open nephrolithotomy, where the surgeon makes a large flank incision and opens the kidney directly, was the standard approach before PCNL became widely adopted in the 1970s and 1980s. Today, open surgery is rarely the first choice, but it hasn’t disappeared entirely. It still plays a role for extremely complex staghorn stones, severely abnormal kidney anatomy, or situations where PCNL has already been attempted and failed.
The key differences come down to recovery and complications. PCNL patients go home about two days earlier on average. Open surgery patients, on the other hand, tend to have fewer postoperative complications like urine leakage and blood in the urine, because the surgeon can close the kidney under direct vision. Both approaches carry a similar risk of bleeding during the operation itself, with transfusion rates of about 14% for PCNL and 19% for open surgery. The stone-free rate slightly favors open surgery (92% vs. 82%), but most urologists consider PCNL the better overall option for the majority of patients because of the faster recovery and smaller incision.