Percutaneous nephrolithotomy (PCNL)

A keyhole operation through a small cut in your back, about 1 centimeter long, that makes a tunnel straight into the kidney to break up and remove large or hard stones.

Also called PCNL, PNL, percutaneous nephrolithotomy, percutaneous nephrolithotripsy, mini PCNL, mini-perc, tubeless PCNL, supine PCNL

Where: Hospital operating room
Anesthesia: General anesthesia (fully asleep)
Time in the room: 1.5 to 3 hours
Hospital stay: Usually 1 night; some go home the same day, some stay 2 nights
Going home with: A nephrostomy tube for 1 to 2 days, or a ureteral stent for 1 to 2 weeks if tubeless
Back to normal: 1 to 3 weeks
Back to work: 1 to 2 weeks for desk work; about 4 weeks for heavy physical work

See the steps

CalyxRenal pelvisStoneUreterSkin

Where it happens. The highlighted part is what this procedure treats.

Overview

Percutaneous nephrolithotomy, usually called PCNL, is the standard operation for large kidney stones. Percutaneous means through the skin, and nephrolithotomy means removing a stone from the kidney. Your surgeon makes a small cut, about 1 centimeter (less than half an inch), in your back and creates a tunnel straight into the kidney. Through that tunnel, a telescope called a nephroscope is used to break up the stone and pull or suck the pieces out.

Because the tunnel is wider than the ureter (the tube that carries urine from the kidney to the bladder), PCNL removes large stones faster and more completely than other methods. AUA and EAU guidelines recommend it as the first choice for kidney stones larger than about 2 centimeters (0.8 inch) and for staghorn stones, which branch through the kidney like a deer's antlers. It is also used for larger stones in the lowest part of the kidney and for stones that other treatments did not clear.

The tunnel is made with a needle guided by ultrasound and X-ray, then widened to about 1 centimeter. A mini PCNL uses a narrower tunnel, which may mean less bleeding for medium-sized stones. In most centers your urologist makes the tunnel during the operation. In some, an interventional radiologist (a doctor who does image-guided procedures) places a starter tube a day or two before.

At the end, the kidney drains through a nephrostomy tube coming out of your back, through a stent inside you from the kidney to the bladder, or both. Many people stay one night. Recovery takes about 1 to 3 weeks.

The parts of your body involved

Your kidneys sit in the back of your belly, just under the lowest ribs. The right one sits a little lower because the liver is above it. Each kidney has a blood-rich outer layer, the cortex, wrapped around a branching drainage system of cups (calyces) that empty into a central funnel (the renal pelvis) and then into the ureter. Large stones fill this drainage system. Your surgeon enters through a calyx on the back side of the kidney, because that path crosses fewer large blood vessels. The neighbors matter too: the lining of the lung sits just above the top of the kidney, the colon lies beside it, and the spleen (on the left) or the liver (on the right) sits above.

Cortex
The outer layer of the kidney, full of tiny filters and blood vessels. The tunnel passes through it, which is why bleeding is the main risk.
Calyces
Cup-shaped chambers inside the kidney. The needle is aimed into a calyx at the back of the kidney.
Renal pelvis
The central funnel where the calyces drain. Large stones often sit here and send branches into the calyces.
Ureter
The tube from kidney to bladder. A wire is passed down it to keep the path secure during surgery.
Neighbors
Lung lining above, colon beside, spleen or liver above. Ultrasound, X-ray and a CT scan before surgery help the surgeon keep clear of them.

Why it’s done

Large stones rarely pass and seldom stay quiet. Over time they can block urine, damage the kidney, bleed, and harbor bacteria. PCNL is offered when a stone is too large or too hard for less invasive methods to clear reliably.

A stone larger than 2 centimeters
At this size, PCNL clears more stone in one session than ureteroscopy or shock waves.
A staghorn stone
Left untreated, staghorn stones often damage the kidney over years and can cause serious infection. Guidelines recommend removing them completely when you are well enough for surgery.
Larger stones in the lower pole
Pieces from the lowest part of the kidney drain poorly after shock waves or ureteroscopy, so PCNL is often preferred for lower pole stones over 1 centimeter.
Hard stones
Cystine, brushite and some calcium oxalate stones resist shock waves and take a long time to break through a ureteroscope.
Other treatments did not work
Stones left after shock waves or ureteroscopy can be cleared in one PCNL.
Repeated infections or bleeding
Stones that keep causing urine infections or blood in the urine, especially infection-related (struvite) stones that must be removed completely.

Other options

Ureteroscopy with laser
A scope passed up from the bladder, with no cut. It can treat stones of 2 to 3 centimeters but often needs two or more sessions. It may be preferred if you cannot stop a blood thinner.
Shock wave lithotripsy
Shock waves from outside the body. Not recommended for stones over 2 centimeters or staghorn stones because too many pieces are left to pass.
Robotic or open stone surgery
Opening the kidney's drainage system through keyhole or open surgery. Rarely needed today, mainly for very complex stones or when another kidney repair is done at the same time.
A drainage tube or watching
For people too unwell for surgery, a long-term drainage tube or careful watching may be chosen, accepting a higher chance of infections and kidney damage.
Removing the kidney
If a stone has already destroyed a kidney so it barely works, removing that kidney can be simpler and safer than clearing the stone.
Dissolving medicine
Pure uric acid stones can sometimes shrink or dissolve with potassium citrate, which makes the urine less acidic. This does not work for calcium or infection stones.

In the operating room, step by step

Press play or pick a step. Each drawing shows what your surgeon is doing at that moment. Your team may do some steps differently.

YouAnesthesia team

1 / 13

1. Going to sleep

You lie on your back while the anesthesiologist puts you fully to sleep and places a breathing tube. Monitors track your heart, breathing and oxygen throughout.

You lie on your back while the anesthesiologist puts you fully to sleep and places a breathing tube. Monitors track your heart, breathing and oxygen throughout.
Many surgeons start by passing a cystoscope, a thin telescope, through the urethra into the bladder and sliding a thin tube up the ureter to the kidney. Dye injected through it outlines the calyces on X-ray, and the tube helps stop pieces from falling down the ureter. A urinary catheter is placed in the bladder.
More detail
Some surgeons also pass a flexible ureteroscope up from below during the operation, so one surgeon works from below while another works through the back. This is called endoscopic combined surgery.
The team carefully turns you face down onto padded supports that protect your face, chest, hips and knees. This position opens a clear path to the back of the kidney. An X-ray C-arm is brought over your back.
More detail
Some surgeons do PCNL with you on your back or slightly tilted, which avoids turning and can make breathing easier for some people. Results are similar, and the choice depends on your body and your surgeon's training.
With ultrasound on your back, and X-ray with dye, your surgeon picks the calyx that gives the straightest route to the stone. The path is chosen to stay below the ribs when possible and clear of the colon and other organs.
A thin needle is passed through the skin of your back into the chosen calyx, watched on ultrasound and X-ray. When urine or dye comes back through the needle, the surgeon knows the tip is in the right place.
More detail
Entering through the tip of a calyx, rather than its neck, avoids the larger blood vessels that run between the calyces.
A soft guidewire is threaded through the needle, into the kidney and down the ureter toward the bladder. The needle comes out. The wire now holds the path open, like a rail, for every step that follows.
A cut about 1 centimeter long is made in the skin beside the wire. A balloon or a series of smooth tubes stretches the path to the kidney, and a hollow working sheath is slid into place. The sheath holds the tunnel open and lets fluid and pieces flow out.
More detail
A standard tunnel is about 1 centimeter wide. A mini PCNL tunnel is roughly half that, which may lower bleeding but takes longer for big stones.
The nephroscope, a telescope with a working channel, goes through the sheath into the kidney. Salt water flows through it to give a clear view of the stone.
A probe through the scope breaks the stone. Ultrasonic probes vibrate the stone apart and suck up the pieces at the same time. Pneumatic probes tap like a tiny jackhammer, and a laser can be used too. Larger pieces are grasped and pulled out through the sheath.
Branches of a staghorn stone reach into calyces the straight scope cannot see. A flexible nephroscope bends around corners, and a wire basket pulls out pieces. Sometimes a second small tunnel is needed to reach a far branch.
More detail
If too much stone remains to remove safely in one sitting, the surgeon may stop and plan a second-look procedure through the same tunnel a few days to weeks later.
The surgeon looks into each calyx with the flexible scope and takes X-ray pictures with dye to look for leftover pieces and confirm urine drains down the ureter.
Many surgeons leave a nephrostomy tube, a soft tube that runs from the kidney out through the skin of your back into a bag. It drains urine and blood, presses gently on the tunnel to limit bleeding, and keeps a path open in case a second look is needed. It usually stays 1 to 2 days.
When the stone is fully cleared and there was little bleeding, many surgeons skip the back tube. Instead, a stent inside you runs from the kidney to the bladder for 1 to 2 weeks, and the skin is closed with a stitch or glue. In selected people, neither a tube nor a stent is left.

After the operation

Right afterward

Waking up
You wake on your back in the recovery room with a deep ache in your side and back and a catheter in your bladder. Pink or red urine is expected.
Pain control
Pills on a schedule plus IV medicine when needed. Some teams use a numbing nerve block. If the tunnel went between the ribs, deep breaths may hurt at first.
Breathing and walking
Deep breaths and a breathing exerciser help keep your lungs open. Nurses help you walk the evening of surgery or the next morning, which lowers the risk of clots and pneumonia.
Checking for bleeding and stone
A blood count the next morning checks for bleeding. Some surgeons order an X-ray or low-dose CT before removing the tube to look for leftover stone. A chest X-ray may be done if the tunnel was near the ribs.
The tube
If you have a nephrostomy tube, it is often capped and then removed on day 1 or 2. You may go home with it in some cases, with teaching on bag care.
Going home
Most people go home after one night once they are eating, walking, urinating after the catheter comes out, and comfortable on pills.

At home

The wound
After the tube comes out, the site often leaks some urine for a day or two. Cover it with gauze and change it when wet. It usually seals within a few days.
Pain
A sore, bruised feeling in the side and back for 1 to 2 weeks. Acetaminophen on a schedule, plus an anti-inflammatory if your surgeon allows it, handles most of it. A few days of a stronger medicine may be prescribed.
Blood in the urine
Pink urine for several days is normal. Bright red urine with clots, or bleeding that returns after it had cleared, needs a call the same day. Delayed bleeding can happen up to 2 to 3 weeks after PCNL.
If you have a stent
Expect urges, frequent urination and side ache when you urinate. The stent is usually removed in 1 to 2 weeks by a string or a quick office cystoscopy.
If you have a nephrostomy tube
Keep the bag below the level of your kidney, empty it when half full, and keep the tube taped so it cannot be pulled. Your team will tell you when it comes out.
Activity and lifting
Walk every day. Avoid lifting more than about 10 to 15 pounds (5 to 7 kilograms), hard exercise and contact sports for about 2 weeks, or as your surgeon advises, while the tunnel through the kidney heals.
Driving
No driving while taking opioid pain medicine, or until you can twist and brake without pain. This is often about 1 week.
Showering
Shower after 24 to 48 hours, covering any tube with plastic. Avoid baths, hot tubs and swimming until the skin site has fully healed, usually about 2 weeks.
Bowels
Pain medicine and less activity can cause constipation. Use a stool softener and drink well.
Preventing the next stone
Large stones often have a cause that can be treated, so most people are offered a 24-hour urine test after the stone analysis. For most stone types: drink enough to make about 2.5 liters of urine a day, keep sodium to about 2,300 milligrams a day or less, eat normal calcium from food, limit meat, poultry and seafood, and eat plenty of fruits and vegetables. Infection (struvite) stones need every fragment cleared and urine infections treated promptly.

Recovery timeline

Day 0
Surgery and the first night
You wake with a side ache, a bladder catheter and often a tube in your back. Walking starts that evening or the next morning.
Day 1
Tube decisions
A blood count, sometimes an X-ray or CT, then the catheter out. A nephrostomy tube is often capped and removed. Many people go home.
Days 2 to 5
Settling at home
The skin site may leak a little urine, then seals. Side ache eases each day. Urine clears from pink to yellow.
Weeks 1 to 2
Stent out, if you have one
A tubeless stent is removed by string or office cystoscopy. Many people return to desk work.
Weeks 2 to 4
Back to most activities
Lifting and exercise restart gradually. Heavy physical work is usually fine by about 4 weeks.
Weeks 4 to 12
Checking for leftover stone
A low-dose CT or X-ray shows whether any pieces remain. If a sizeable piece is left, a second procedure may be planned.
Months 1 to 3
Prevention plan
Stone analysis and a 24-hour urine test guide diet changes or medicines to keep new stones from forming.
Long term
Watching for return
Many people have a scan about once a year for a few years, especially after a staghorn stone, so any new stone is found while it is small.

What it feels like

PCNL is a bigger step than other stone treatments, and most people feel it for a week or two. The ache is real but manageable, and the relief of having a large stone gone is often what people remember most.

The night before
Worry about waking with a tube in your back, about bleeding, or about losing the kidney. If you have had months of infections or pain, there may also be relief that something is finally being done.
What helpsAsk your surgeon how likely a tube is, how long it stays, and what the plan is if bleeding happens. Knowing the plan settles many fears.
Waking up
A deep, heavy ache in your side and back, a catheter in your bladder, and a bag of pink urine at the bedside. Grogginess and a sore throat from the breathing tube are common.
What helpsAsk for pain medicine before the pain builds. Use the call button for help moving. Small sips of water help the throat.
The first deep breaths and first walk
Breathing in deeply can catch in your side, especially if the tunnel went near the ribs. The first walk feels slow and stiff, and the tube can feel like it is pulling.
What helpsHug a pillow against your side when you breathe deeply or cough. A nurse can secure the tube and bag so you can walk without tugging.
Seeing the stone
Many people are surprised by how much stone came out. Some feel shaken that it was inside them.
What helpsAsk for the pieces or a photo. It can help to understand why the stone needed this approach.
Tube removal
A strange pulling, sliding feeling for a few seconds, then relief. The site may leak urine onto the gauze for a day or two, which can be alarming if you were not expecting it.
What helpsBreathe out slowly while it comes out. Keep extra gauze and tape at home. Leaking that slows each day is normal.
The first week at home
Tired, sore, and unsure how to sleep. Lying on the treated side may hurt. Some people feel low after the hospital stay.
What helpsSleep on your back or the other side with a pillow behind you. Short walks several times a day help energy and mood.
Waiting for the follow-up scan
Worry that pieces were left and that you will need another operation.
What helpsAsk your surgeon what they expect to see. Small fragments are often watched rather than treated.

How well it works

Success means all or nearly all the stone is gone, the kidney drains well, and infections and pain stop. In a large international study, about 3 in 4 people were stone-free after a single PCNL. The rate is higher for simpler stones and lower for complex staghorn stones.

Stone-free status
A low-dose CT is the most accurate way to look for leftover pieces, usually within the first 1 to 3 months.
A second look, if needed
Sizeable leftover pieces may be removed through the same tunnel or with ureteroscopy. Very small pieces are often watched.
Kidney function
Blood tests check kidney function. Removing a large stone usually protects the kidney's long-term function. The tunnel leaves only a tiny scar in the kidney.
Stone analysis and 24-hour urine
Knowing the stone type and urine chemistry lets your team tailor diet changes and, when needed, medicines that lower the chance of another large stone.

Risks

Every operation has risks. These are the ones people ask about most, with honest odds where good numbers exist. Your surgeon’s own results matter more than averages.

Common

Pain in the side and at the tube siteMost people

Expected for 1 to 2 weeks and eased by medicines.

Blood in the urineAlmost everyone

Pink or red urine for several days.

Fever after surgeryAbout 1 in 10 people

Usually short-lived and treated with antibiotics. More likely with infection-related stones.

Leftover stoneAbout 1 in 4 people are not fully stone-free after one PCNL

Some stone may remain, especially with staghorn stones. Small pieces may be watched. Larger ones may need a second procedure.

Less common

Bleeding that needs a blood transfusionAbout 1 to 6 in 100 people

More likely with very large stones, more than one tunnel, or a standard-size tunnel.

Urine leaking from the tube site

Leaking that lasts more than a few days usually stops once a stent is placed or the ureter drains well.

Fluid or air around the lung

More likely when the tunnel goes between the ribs. It may need a small chest tube for a day or two.

Serious infection (sepsis)

Infection that spreads to the blood and needs IV antibiotics and close monitoring, sometimes in intensive care.

A second procedure

A planned or unplanned second look to clear remaining stone.

Rare

Bleeding from an injured arteryAbout 1 in 100 people or fewer

Heavy bleeding, sometimes 1 to 3 weeks later, from a damaged artery inside the kidney. An interventional radiologist can usually seal it by blocking the vessel through a thin catheter (embolization).

Injury to nearby organs

The colon, spleen, liver or lung. Very rare with careful imaging. Colon injury may need extra drainage or surgery.

Blood clots in the legs or lungs

Walking early and moving your legs lower the risk.

Loss of the kidney

Extremely rare. Removing the kidney is a last resort for bleeding that cannot be controlled any other way.

Call your care team or go to the emergency room if

Fever of 101°F (38.3°C) or higher, or shaking chills
Bright red urine with clots, or bleeding that returns after your urine had cleared
Sudden severe pain in your side or back, especially with dizziness, fainting or a racing heartbeat
Your nephrostomy tube falls out, or stops draining and you have pain
You cannot urinate, or you pass very little urine
Redness, swelling or pus at the skin site, or leaking that gets heavier instead of lighter
Vomiting that keeps you from holding down fluids or medicines
Chest pain, shortness of breath, or a swollen, painful leg (call 911 for chest pain or trouble breathing)

Questions to ask your surgeon

How big is my stone, what is it likely made of, and why is PCNL the best option for me?
Will you make the tunnel yourself, or will a radiologist place it before surgery?
Will you use a standard or a mini tunnel, and might you need more than one?
Will I be lying on my front or my back?
Do you expect to leave a nephrostomy tube, a stent, or neither? For how long?
How many nights will I likely stay in the hospital?
What is the chance I will need a second procedure?
What is my risk of needing a blood transfusion?
When do I stop and restart my blood thinner?
What lifting and work limits should I follow, and for how long?
Will you analyze the stone and order a 24-hour urine test?

Words you may hear

Percutaneous: Through the skin.
Nephrolithotomy: An operation to remove a stone from the kidney.
Staghorn stone: A large stone that branches into several calyces, shaped like a deer's antlers. Often linked to infection.
Calyx: One of the cup-shaped chambers inside the kidney where urine first collects. Plural: calyces.
Tract: The tunnel made from the skin into the kidney.
Nephroscope: A telescope with a working channel, passed through the tract to see and remove the stone.
Nephrostomy tube: A soft tube from the kidney out through the skin of the back, draining urine into a bag.
Tubeless PCNL: Ending the operation without a back tube, usually with a stent inside instead.
Mini PCNL: PCNL through a narrower tunnel, often used for medium-sized stones.
Ultrasonic lithotripter: A probe that vibrates the stone into pieces and suctions them out at the same time.
Fluoroscopy: Live X-ray pictures used to guide needles, wires and tubes.
Struvite: A stone type formed when certain bacteria infect the urine. It can grow quickly into a staghorn stone.
Embolization: Blocking a bleeding blood vessel from the inside through a thin catheter, done by an interventional radiologist.
Second-look procedure: A return to the operating room, often through the same tunnel, to remove remaining stone.

Common questions

How big is the scar?

The skin cut is about 1 centimeter (less than half an inch), a little bigger if more than one tunnel is needed. It usually fades to a small mark on your back or side.

Will I wake up with a tube in my back?

Maybe. Many surgeons leave a nephrostomy tube for a day or two. If the stone is fully cleared and bleeding is minimal, many go tubeless with a stent instead. Your surgeon will tell you their usual plan, but the final choice is made at the end of the operation.

Why not break the stone with a laser from below, with no cut?

For stones larger than about 2 centimeters, a ureteroscope often needs two or more sessions and leaves more pieces behind. PCNL usually clears a large stone in one operation.

Can PCNL be done while I lie on my back?

Yes. Many surgeons do supine PCNL, especially for people who have trouble lying face down or when combining with a scope from below. Results are similar to the face-down position.

Does PCNL damage my kidney?

The tunnel leaves a small scar in the kidney, and studies show overall kidney function is usually preserved. Leaving a large stone in place is generally a bigger threat to the kidney than the operation.

How long will I be off work?

Most people return to desk work in 1 to 2 weeks and to heavy physical work in about 4 weeks. Having a stent can make the first week or two less comfortable.

How do I keep a big stone from coming back?

Start with fluids: enough to make about 2.5 liters of urine a day. Keep salt low, eat normal amounts of calcium from food, limit meat, and eat plenty of fruits and vegetables. A 24-hour urine test may show a specific cause, such as low citrate or high calcium, that diet or medicine can fix. If your stone was an infection stone, prompt treatment of urine infections matters most.

Sources this page draws on

American Urological Association and Endourological Society, Surgical Management of Stones: AUA/Endourological Society Guideline (2016)
European Association of Urology, EAU Guidelines on Urolithiasis
Clinical Research Office of the Endourological Society (CROES), The CROES Percutaneous Nephrolithotomy Global Study (2011)
American Urological Association, Medical Management of Kidney Stones: AUA Guideline (2014)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Kidney Stones
Urology Care Foundation, Kidney Stones

Written November 2026. This page explains what usually happens. It is not medical advice and does not replace a conversation with your own surgeon, whose plan for you comes first.

Percutaneous nephrolithotomy (PCNL)

Overview

The parts of your body involved

Why it’s done

Other options

Getting ready

Weeks before

The week before

The day before

The morning of

In the operating room, step by step

1. Going to sleep

After the operation

Right afterward

At home

Recovery timeline

What it feels like

The night before

Waking up

The first deep breaths and first walk

Seeing the stone

Tube removal

The first week at home

Waiting for the follow-up scan