Percutaneous Nephrolithotomy in the managemant of urinary stones

Abstract

CONFERENCE ABSTRACT

Percutaneous Nephrolithotomy (PCNL) in the Management

of Urinary Stones: Indications, Technique, and Outcomes

Dr Sadaf Saadi

Department of Urology, Sarhad University 

 BACKGROUND

Percutaneous Nephrolithotomy (PCNL) is the gold-standard minimally invasive surgical procedure for the management of large, complex, and refractory urinary calculi. First described by Fernström and Johansson in 1976, PCNL provides direct nephroscopic access to the renal collecting system, enabling efficient stone fragmentation and extraction. Urinary stone disease affects approximately 10–15% of the global population, with a lifetime recurrence risk of up to 50%. Current European Association of Urology (EAU) and American Urological Association (AUA) guidelines recommend PCNL as the first-line surgical treatment for renal calculi ≥20 mm and as salvage therapy following failed extracorporeal shockwave lithotripsy (ESWL) or ureteroscopy (URS).

 OBJECTIVE

To comprehensively review the indications, patient selection criteria, operative technique, clinical outcomes, comparative efficacy against alternative modalities, and complication profile of PCNL in the contemporary management of urinary stone disease.

 INDICATIONS & PATIENT SELECTION

PCNL is primarily indicated for renal stones ≥20 mm in the upper and mid pole, lower pole calculi ≥15 mm, and complex stone burdens including complete and partial staghorn calculi, struvite, and cystine stones. Additional indications include failed ESWL or URS with residual fragments >4 mm, stones in anatomically abnormal kidneys (horseshoe kidney, pelvi-ureteric junction obstruction), and morbidly obese patients. Absolute contraindications include uncorrected coagulopathy and untreated urinary tract infection, which must be resolved prior to surgery.

SURGICAL TECHNIQUE

PCNL is performed under general or spinal anaesthesia with the patient in the prone or modified supine (Valdivia) position. A ureteric catheter is placed cystoscopically to facilitate retrograde pyelography. Percutaneous access to the target calyx is achieved under fluoroscopic or ultrasound guidance using an 18-gauge needle. The access tract is sequentially dilated to 24–30 Fr using Amplatz serial dilators or a one-step balloon dilator, and an Amplatz sheath is secured. A rigid or flexible nephroscope is introduced, and stone fragmentation is performed using ultrasonic (Cyberwand), pneumatic, or laser (Ho:YAG or Thulium fibre) lithotripsy. Stone fragments are extracted with forceps or a retrieval basket. The procedure concludes with placement of a nephrostomy tube, or in selected cases a tubeless exit with an indwelling ureteric stent.

  OUTCOMES

PCNL achieves stone-free rates of up to 95% for renal calculi ≥20 mm in experienced centres, representing the highest efficacy among available stone management modalities for this size category. Single-stage success is achieved in approximately 88% of cases, while stone-free rates for staghorn calculi range from 70–85% depending on stone burden and anatomical complexity. Mini-PCNL (≤14 Fr access sheath) achieves stone-free rates of approximately 83% with reduced blood loss and a smaller nephrostomy tract. Mean operative time ranges from 45–120 minutes depending on stone complexity, with a hospital stay of 2–3 days (1–2 days for tubeless cases) and return to normal activity within 10–14 days. Ultrasound-guided access has been shown to reduce radiation exposure by up to 60% without compromising stone-free outcomes.

COMPARATIVE EFFICACY

When compared to ESWL and URS/RIRS for stones ≥20 mm, PCNL demonstrates superior stone-free rates (95% vs 40–60% for ESWL and 70–80% for URS). ESWL and URS carry lower complication profiles and require no hospital admission; however, their efficacy is significantly diminished for larger, harder (cystine), and more complex stone burdens. PCNL remains the preferred modality for staghorn calculi, with ESWL achieving only 20–40% stone-free rates in this setting. The choice of modality must be individualised based on stone size, composition, location, renal anatomy, patient comorbidities, and institutional expertise.

COMPLICATIONS

The overall complication rate for PCNL is approximately 20–25%, with major complications (Clavien-Dindo Grade ≥III) occurring in ~5% of cases. Major complications include significant haemorrhage requiring blood transfusion (5–7%) or angioembolisation, urosepsis (2–3%), pleural injury with supracostal access, and colonic injury (<0.5%). Minor complications (Clavien I–II, ~20%) include post-operative fever and urinary tract infection, peri-nephric fluid collection, urinary extravasation, and residual stone fragments. Prophylactic antibiotics, appropriate patient selection, and meticulous operative technique are key measures in minimising complication rates.

SPECIAL SITUATIONS & EMERGING TECHNIQUES

Mini- and ultra-mini-PCNL (access sheaths 6–14 Fr) have expanded the application of percutaneous nephrolithotomy to paediatric patients and smaller stone burdens, with comparable efficacy and reduced morbidity. Tubeless and totally tubeless PCNL, avoiding nephrostomy tube placement in selected cases, further reduces post-operative pain and hospital stay. The supine (Valdivia) technique allows simultaneous ureteroscopic access and is preferred in obese or cardiopulmonary high-risk patients. Emerging technologies including Thulium fibre laser lithotripsy, artificial intelligence-guided fluoroscopy, and three-dimensional CT reconstruction for pre-operative planning are anticipated to further improve outcomes and reduce complication rates.

 CONCLUSIONS

PCNL remains the most effective surgical intervention for large, complex, and staghorn renal calculi, achieving stone-free rates of up to 95% in experienced centres. Careful patient selection guided by current EAU/AUA guidelines, thorough pre-operative imaging, prophylactic antibiosis, and mastery of percutaneous access technique are essential to optimise outcomes. Continued technological innovation and the evolution toward smaller access tracts and improved energy sources promise to further enhance the efficacy and safety profile of this benchmark urological procedure.

Keywords: Percutaneous Nephrolithotomy; PCNL; Urinary Stone Disease; Nephrolithiasis; Lithotripsy; Minimally Invasive Urology; Staghorn Calculi; Mini-PCNL; Urological Surgery

References

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