Table of Contents
What is PCNL
Percutaneous nephrolithotomy (PCNL) is the emerging surgical procedure for staghorn calculi and large renal stones (usually ≥2 cm). This procedure usually staged or done in steps and offers the best chance of a high stone-free rate for complete or partial staghorn stones.
Mini vs Standard PCNL Operation
There are two types of PCNL. Mini-PCNL uses a smaller tract and instruments (15−18 F sheath) than standard PCNL (24−30 F sheath), resulting in less bleeding, shorter hospital stays, and lower postoperative pain, with comparable stone-free rates, especially for stones under 222 cm. However, mini-PCNL may sometimes require a longer operation time, and standard PCNL can have a higher stone-free rate for very large or complex stones.
Percutaneous nephrolithotomy (PCNL) Operation Pre-operative workup
- Medical History for prior stones, infections, bleeding, hypertension and diabetes.
- CT scan KUB with or without contrast is required to asses stone size, branching anatomy, stone burden.
- Laboratory Tests required before hand includes CBC, coagulation profile, liver functions test, renal function tests and serum electrolytes.
- Urine culture and sensitivity test is usually required to treat positive cultures with appropriate antibiotics before procedure; residual bacteriuria is a major risk factor for post-PCNL sepsis.
- Stop any anticoagulation medicine as per local protocol.
- Informed consent with discussion of possible staged procedures.
How PCNL Operation is performed (Step-by-step operative technique)
Anesthesia and positioning
Commonly the procedure will be performed in prone position and general anesthesia
Retrograde ureteric catheter insertion
A ureteric catheter or flexible cystoscope may be placed to inject radiopaque contrast media to opacify the collecting system for calyx selection and puncture.
Collecting system puncture (Percutaneous key whole access)
Under fluoroscopy and/or ultrasound the desired calyx (often lower/middle calyx) will be punctured with an access needle. For staghorn stones, access planning may require multiple punctures to reach different stone branches.
Guidewire insertion
A guidewire is advanced into the collecting system and ideally down the ureter.
Tract dilation for sheath insertion
Sequential tract dilation or balloon dilation to a desired sheath size (standard PCNL 24–30Fr; “mini” PCNL uses smaller sheaths). Choice depends on stone burden and bleeding risk.
Nephroscopy and stone fragmentation
A rigid/semirigid nephroscope will be passed through sheath. Stones will be fragmented using pneumatic jackhammer, ultrasonic, combined lithotripters, or holmium laser, then fragments will be removed with graspers/forceps or suction. All the accessible calyces will be inspected with flexible nephroscopy for any residual fragments. Placement of double-J stent may be indicated. For very large staghorn burden, multiple tracts or staged procedures will be often required to achieve maximum stone clearance.
Nephrostomy tube placement for proper drainage
In conventional “tubed” PCNL nephrostomy tube will be inserted for adequate drainage and if the bleeding is minimal and drainage via ureteric stent is adequate then tubeless PCNL (nephrostomy tubing omitted) can be opted.
Immediate postop imaging
Plain x-ray or low-dose CT may be used in the immediate postoperative period or within the first few days for residual fragments.
Staged (Step by step) Percutaneous Nephrolithotomy (PCNL) procedures
Complete staghorn stones may not be cleared in a single session in that case staged PCNL will be best option
Indications of PCNL operation (when to choose)
Large renal stones ≥2 cm, especially staghorn (partial or complete) stones occupying multiple calyces.
Complex/branched stones where shock wave lithotripsy (ESWL) is unlikely to succeed. Stones causing obstruction, recurrent infection, or renal function threat where definitive clearance is required.
Contraindications of PCNL Surgery (when not to choose)
Absolute contraindications
Uncorrected/ongoing urosepsis (active systemic infection should be controlled first)
Bleeding disorder or coagulopathy.
Relative contraindications
Pregnancy (try to avoid the procedure if necessary use specialized centers).
Morbid obesity or severe cardiopulmonary disease making prone positioning/high risk
Anatomic anomalies may increase risk but are not absolute contraindications.
Common complications
Fever due to infection (sepsis)
Bleeding during or just after procedure and may require blood transfusion
Injury to the viscera (thoracic/pleural, bowel/colon) during procedure
Urine leak / urinoma, Usually managed with drainage (nephrostomy/stent) and observation.
Residual stone / need for secondary procedures. Staghorn stones frequently require staged Percutaneous nephrolithotomy or combined approaches; expect possible reintervention to reach stone-free status.