What to Know About Percutaneous Nephrolithotomy (PCNL)

 In this blog, I explain exactly what happens during a Percutaneous Nephrolithotomy (PCNL) procedure—how it works, who it’s for, and what to expect. I also cover the differences between conventional, mini, and micro PCNL, and walk through complication rates, costs, and success rates based on surgical technique. If your doctor mentioned PCNL, this is the deep-dive you need.

Key Takeaways:

• PCNL removes kidney stones by creating a tract through the skin

• It’s used for large or complex kidney stones, not for ureteral stones

• Mini and micro versions reduce complication risks

• Success depends heavily on the surgical access point used

 If you’ve been told you need a Percutaneous Nephrolithotomy (PCNL), you might be wondering—what is this? Why not something less invasive?

Let me walk you through everything I’ve learned about this advanced procedure, including what it involves, who it’s for, and how it compares to other treatment options for kidney stones.

What Is Percutaneous Nephrolithotomy?

Let’s break down the name first.

• Percutaneous = through or around the skin

• Nephro = kidney

• Lithotomy = removal of stones

So, Percutaneous Nephrolithotomy literally means removing a kidney stone by going through the skin. This isn’t a figure of speech—it’s exactly what happens.

A small puncture is made in your side, directly through your skin and into the calyx of your kidney. The idea is to get as close as possible to the stone and create a pathway for surgical instruments to go in and remove it.

How Is the Puncture Made?

To guide this puncture safely, surgeons typically use fluoroscopy—a kind of live-action X-ray. Some centers also use ultrasound, CT scans, or ureteroscopy to help guide the needle.

Once the needle is correctly placed into the kidney, the surgeon dilates the tract so tools can pass through.

Tract Dilation: Traditional vs. Balloon Techniques

Traditionally, dilation is done using sheaths—tubes of increasing size that gradually widen the hole.

Today, many surgeons use balloon dilation, which gently inflates a small device to widen the access tract more smoothly. 

How Big Is This Access Tract?

Here’s where it gets interesting. Tract size is measured in French units (Fr), which refers to the circumference of the opening.

• Conventional PCNL: 24–30 Fr = ~8–10 mm in diameter

• Mini PCNL: 14–20 Fr = ~4.7–6.7 mm

• Micro PCNL (used mostly in children): 4.85 Fr = ~1.6 mm

So in a conventional PCNL, they’re making a hole about the size of a centimeter in your side and kidney. This has led to advancements in mini and micro PCNL, which lower the risk of bleeding and complications but may limit how much stone material can be removed.

Stone Removal and Fragmentation

Once the tract is ready, the surgeon inserts a nephroscope—a rigid tool that gives a visual of the stone inside your kidney. In some cases, they’ll also use a ureteroscope if the stone is hard to reach.

For smaller stones, they can use stone baskets or graspers to pull them out whole.

For larger stones, the surgeon needs to break them up first. This is done using various types of lithotripters (stone-breaking tools), which vary by hospital and surgeon preference. Once the stones are broken into small enough pieces, they’re removed through the same tract.

Complications and Risks

This is the most invasive stone removal method available—but surprisingly, it has a complication rate of just 15%.

The most common risks are:

• Bleeding

• Infection

These are well-known to surgeons and usually managed with close monitoring and follow-up care.

Cost of Percutaneous Nephrolithotomy

Here’s the kicker. It’s not cheap.

The average cost in the U.S. is about $30,000 per procedure. Depending on where you live, it can range from $25,000 to $37,000.

And because large or complex stones often require multiple procedures, your final bill could land between $60,000 and $100,000.

Who Should Get PCNL?

According to the American Urological Association, PCNL is not a first-line treatment for ureteral stones.

Instead, it’s reserved for patients who:

• Have large kidney stones (over 20 mm or 2 cm)

• Have complex stones or multiple stones

• Have failed other treatments like shock wave lithotripsy or ureteroscopy

If your stone is in the ureter, PCNL should only be considered after everything else has failed.

Success Rates and Access Techniques

One of the biggest factors that determines success is access approach—how the surgeon reaches your kidney.

There are two main types:

• Superior access (from the top of the kidney)

• Inferior access (from the middle or lower part of the kidney)

Superior access gives the surgeon better range of motion and visibility. Inferior access is more common because it’s easier to perform, but it limits what the surgeon can do inside your kidney.

Let’s look at how this affects outcomes:

For Stones in the Renal Pelvis

• Superior access: 100% clearance

• Inferior access: 92.5% clearance

For Stones in the Kidney

• Superior access: 95.7% clearance

• Inferior access: 82.3% clearance

For Stones in Both Kidney and Pelvis

• Superior access: 94.8% clearance

• Inferior access: 81.9% clearance

So clearly, superior access leads to higher success rates—but it’s technically more challenging and not all surgeons are trained for it.

Final Thoughts: Is PCNL Right for You?

If your urologist recommends Percutaneous Nephrolithotomy, it’s probably because your stone is large, complex, or you’ve already tried and failed other options.

It’s a big procedure. It’s expensive. But it’s also highly effective when done correctly.

And now that you know how it works, what it costs, and what affects success, you’re better equipped to have a meaningful conversation with your surgeon.

The more you know, the more confident you’ll be when it comes time to make the tough decisions.