Percutaneous nephrolithotomy (PCNL)

CONDITIONS

Written and Medically Reviewed by Mr Ivo Dukic, Consultant Urologist | Last updated: 13/03/2026

Large or complex kidney stones?

Have you been diagnosed with large or complex kidney stones? Navigating treatment options can be overwhelming. Percutaneous nephrolithotomy (PCNL) is a minimally invasive approach offering potentially greater stone clearance compared to alternative methods. This article explains the PCNL procedure, exploring its indications, risks, alternatives, and exciting advancements in the miniaturisation of this keyhole procedure for kidney stones.

Understanding percutaneous nephrolithotomy (PCNL)

PCNL involves creating a small access channel through the back directly into your kidney using imaging (ultrasound and X-rays). Through this channel, specialised instruments including special cameras are introduced to visualise, break and remove kidney stones. Compared to open surgery, PCNL has shorter hospital stays, faster recovery times, and less scarring. Many patients stay in hospital for only one to two nights, and some centres now offer day-case PCNL procedures.

When compared to flexible ureterorenoscopy (FURS), PCNL achieves better rates of stone clearance, especially for large or complex stones or stones in the lower part (pole) of the kidney [1,2]. A recent Cochrane systematic review of 42 randomised controlled trials confirmed that PCNL improves stone-free rates compared with FURS, with probably little or no difference in major complications [2].

When is PCNL considered?

PCNL is typically recommended for the treatment of:

Large stones: Stones exceeding 2 cm in diameter, or lower pole stones greater than 1 cm with unfavourable factors for shock wave lithotripsy (SWL), or those resistant to non-surgical treatments [1,3].
Complexly shaped stones: Stones with intricate branches or in challenging anatomical positions.
Staghorn calculi: Large, branched stones resembling antlers, requiring extensive fragmentation and removal.
Multiple stones: Situations where multiple stones are present within the kidney necessitate a comprehensive or combined approach with PCNL and / or flexible ureterorenoscopy.

Exploring Alternatives:

Before considering PCNL, your urologist will weigh up various options with you depending on your specific situation:

Shock wave lithotripsy (SWL): Focused shock waves break down smaller stones into fragments that your body eliminates naturally. For large stones, this can lead to many treatments and incomplete stone clearance.
Flexible ureterorenoscopy (FURS): A thin, flexible scope navigates the ureter (urine tube) to reach and remove smaller stones. Sometimes this is used at the same time as doing a percutaneous nephrolithotomy operation to improve the rate of stone clearance. A recent UK multicentre trial (PUrE RCT 2) showed that PCNL was more effective and more cost-effective than FURS for lower pole stones between 10 and 25 mm [7].

Further information on these procedures can be found on the kidney stone surgery section or through the European Association of Urology or the British Association of Urological Surgeons.

A revolution in miniaturisation

Minimising access and instruments in PCNL offers several advantages:

Reduced pain and scarring: Smaller incisions translate to less tissue disruption and faster healing.
Shorter hospital stays: Minimally invasive approaches often lead to quicker discharge and recovery, including some patients having day-case PCNL procedures.
Reduced blood loss: Meta-analyses confirm that miniaturised PCNL is associated with lower blood loss and transfusion rates compared to standard PCNL [1,5].
Comparable stone-free rates: Multiple meta-analyses confirm that miniaturised PCNL achieves similar stone-free rates to standard PCNL for appropriately selected patients [1,5].

It is worth noting that smaller instruments may be associated with higher intrarenal pressures during surgery, which is why your surgeon will select the most appropriate instrument size for your individual stone and kidney [1].

Types of PCNL procedures:

The published classification of PCNL techniques is based on the size of the access tract (sheath) used [5,6]:

Supine Standard PCNL (tract size greater than 22 Fr / approximately 7 mm): Patients were traditionally operated on in a face-down (prone) position for many years. Performing the PCNL procedure whilst on your back (supine) allows your lungs to work more naturally, making anaesthesia easier, potentially reducing recovery time and lowering the chance of bowel injury. A large international study of over 5,800 patients across 26 countries confirmed lower patient morbidity with supine PCNL [4]. This slightly larger access is used to get maximum stone clearance and is particularly useful for large stones (staghorn stones), multiple stones, complex kidney anatomy or infective kidney stones.
Mini PCNL (tract size 14-22 Fr / approximately 5-7 mm): This technique utilises a mini access channel, offering reduced blood loss and shorter hospital stays compared to standard PCNL [1,5]. This is particularly used for stones between 1.5 cm and 2.5 cm or difficult-to-access kidney stones and uses lasers to break up kidney stones.
Super Mini / Ultra-Mini PCNL (tract size 10-14 Fr / approximately 3-5 mm): The smallest access is used, which minimises pain, scarring, and blood loss significantly [5]. It is suitable only for relatively small stones or those stones which may be difficult to access through a flexible ureterorenoscope (often lower pole stones).
Endoscopic Combined Intrarenal Surgery (ECIRS): This uses a combination of a puncture in the back (PCNL) and a flexible ureteroscope inside the kidney. This type of surgery is typically carried out with two surgeons, where one surgeon performs a PCNL procedure while the other surgeon performs a flexible ureteroscopy. This enables fragments of stones in a variety of positions within the kidney to be manipulated inside the kidney before removal through the plastic tubing in the kidney.

Considering the Risks:

Whilst minimally invasive, PCNL still carries potential risks, including:

Mild bleeding into your urine is likely to occur in every patient undergoing PCNL.
Stent symptoms, nephrostomy symptoms or a urinary catheter. Most patients are left with a ureteric stent, which allows the kidney to drain following the procedure. This is typically left in for 3-5 days and removed using some strings which are left outside the water pipe (urethra) following the procedure. Almost all patients under my care (90%+) are left with a stent or nephrostomy after a PCNL procedure. Some patients are also left with a catheter and/or nephrostomy. Typically this is done to try and prevent complications during surgery if necessary.
Failure to clear all of the stones is likely to occur (varies on stone volume, kidney anatomy and patient factors). The more complex the presentation and the larger the amount of stone the less likely it is we can achieve complete stone clearance. This is assessed on a CT scan 2-3 months following the procedure to look for any remaining stone fragments.
Stone recurrence is likely to happen in approximately 50% of patients within 5 years [8,9].
Bleeding: Blood transfusion is required in approximately 5-10% of standard PCNL cases, and less frequently with miniaturised techniques [1,5,10]. If significant bleeding occurs, patients may also require embolisation treatment which can affect kidney function, and very rarely open surgery to the kidney (if the bleeding continues).
Infection: Post-operative infections (in the urine, skin or blood) can often be cured with antibiotics. Serious infections including sepsis occur less than 5% of the time but are more frequent in large or infective kidney stones and women [11]. Staghorn calculi, Gram-negative bacteria in the urine, and female sex are identified as independent risk factors for inflammatory complications following PCNL [11].
Kidney injury, including kidney failure: Minor damage to the kidney during the procedure is a potential risk.
Leakage: Urine leakage from the access site which is usually temporary, may occur.
Failure to gain access to the kidney occurs in every 1 in 50 patients. If this happens your surgeon will discuss alternative options or try to gain access through a different route.
Injury to nearby organs: although rare this can include puncturing the space around the lungs, or injury to the bowel, spleen or liver. If a serious injury occurs to a nearby organ this can be life-threatening.

Choosing the Right Approach:

Your urological surgeon will consider your stone size, location, and individual medical history and will guide you towards the most suitable form of treatment for your kidney stone. Open communication and discussing your concerns are crucial in making an informed decision. Almost all of our PCNL surgeries are carried out with a modern supine approach with around 70-90% of our patients undergoing mini PCNL or ultra-mini PCNL surgeries. We use the latest laser technology (Thulium where possible) and suction sheaths to improve our stone clearance rates. We regularly audit our stone-free rates and complication rates after surgery and are happy to discuss these with you for your specific stone type.

Further links

Beyond the procedure:

Remember, successful stone management extends beyond the procedure itself:

Hydration: Aim for 2.5 -3 litres of water daily to prevent or delay further stone formation.
Dietary modifications: Minimize stone-forming foods like animal protein and oxalates based on your stone type.
Scheduled check-ups can ensure timely detection and management of any recurrent stones if required.
After surgery we recommend our patients undergo a CT KUB scan to ensure that their stones are completely cleared, or if they are not clear we can discuss potential additional treatment.

Please note:

This article provides general information and should not substitute for professional medical advice that is tailored to your situation with your urologist. Always consult a urologist for a personalised assessment and treatment plan.
The specific risks and benefits of PCNL may vary depending on individual circumstances and presentation.

Mr Ivo Dukic is one of the UK's premier complex stone surgeons and top kidney stone specialists, offering world-class urological care in Birmingham. Recognised as the leading PCNL expert in the West Midlands, Mr Dukic delivers cutting-edge minimally invasive treatments, including:

Mini-PCNL for optimal outcomes.
Ultra-mini PCNL for reduced recovery times.
Advanced endoscopic removal and complex renal stone surgery.

Mr Dukic combines years of specialist experience with the latest innovations, such as suction sheaths and LASER technology in both mini PCNL and flexible ureterorenoscopy to provide exceptional treatment outcomes.

You can schedule an appointment with him for expert, bespoke advice through his Top Doctors profile or book an appointment through Harborne Hospital, HCA Healthcare, the Priory Hospital, Edgbaston, Circle Health Group or Droitwich Spa, Circle Health.

References

Skolarikos A, Geraghty R, Somani B, et al. European Association of Urology guidelines on the diagnosis and treatment of urolithiasis. Eur Urol. 2025;88(1):64-75.
Soderberg L, Gajic I, Jeppson A, et al. Percutaneous nephrolithotomy versus retrograde intrarenal surgery for treatment of renal stones in adults. Cochrane Database Syst Rev. 2023.
Türk C, Petrik A, Sarica K, et al. EAU guidelines on interventional treatment for urolithiasis. Eur Urol. 2016;69(3):475-82.
de la Rosette J, Assimos D, Desai M, et al. The Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study: indications, complications, and outcomes in 5803 patients. J Endourol. 2011;25:11-17.
Ruhayel Y, Ömerbegović M, Walcher U, et al. Tract sizes in miniaturized percutaneous nephrolithotomy: a systematic review from the European Association of Urology Urolithiasis Guidelines Panel. Eur Urol. 2017;72(1):32-43.
Helal M, Black T, Snodgrass W, et al. The Hickman peel-away sheath: alternative for pediatric percutaneous nephrolithotomy. J Endourol. 1997;11(3):171-2.
PUrE RCT 2 Investigators. Clinical and cost effectiveness of flexible ureterorenoscopy and percutaneous nephrolithotomy for lower-pole stones of 10-25 mm. Eur Urol Focus. 2025;11(5):684-94.
Ziemba JB, Matlaga BR. Epidemiology and economics of nephrolithiasis. Investig Clin Urol. 2017;58(5):299-306.
Kittanamongkolchai W, Joshi D, Flowers SA, et al. Risk of kidney stone recurrence after the first and subsequent episodes. Mayo Clin Proc. 2022;97(8):1421-9.
Falahatkar S, Moghaddam AA, Kamranmanesh M, et al. Decreasing the complications of PCNL with alternative techniques. Pak J Med Sci. 2009;25(3):353-8.
Wang S, Zhang Y, Zhang X, et al. Risk factors for systemic inflammatory response syndrome after percutaneous nephrolithotomy. Prog Urol. 2018;28(11):582-8.