What are the surgical options for kidney stones?

Surgical Options for Kidney Stones

The surgical management of kidney stones depends primarily on stone size, location, and patient factors, with percutaneous nephrolithotomy (PCNL) being the first-line treatment for stones larger than 20 mm due to its superior stone-free rates compared to other modalities. 1

Treatment Options Based on Stone Size and Location

Renal Stones ≤20 mm (Non-Lower Pole)

• Either shock wave lithotripsy (SWL) or ureteroscopy (URS) may be offered as first-line treatment 1
• URS is associated with higher stone-free rates in a single procedure but slightly higher complication rates 1
• SWL has less morbidity but may require multiple treatments 1

Renal Stones >20 mm

• PCNL should be offered as first-line therapy due to significantly higher stone-free rates (94% vs 75% for URS) 1
• SWL should not be offered as first-line therapy due to poor success rates (median success rate of only 10% for stones >20mm) 1
• Success of PCNL is less dependent on stone composition, density, and location compared to other modalities 1

Lower Pole Stones

• For stones ≤10 mm: Either SWL or URS can be offered with similar stone-free rates 1
• For stones >10 mm: SWL should not be used as first-line therapy; URS or PCNL are preferred 1
• For lower pole stones 10-20 mm, median success rates are: SWL (58%), URS (81%), and PCNL (87%) 1

Specific Surgical Techniques

Percutaneous Nephrolithotomy (PCNL)

• Involves creating a tract through the back into the renal pelvis to directly access and fragment stones 2
• Key components of proper PCNL technique:
  • Flexible nephroscopy should be routinely performed to access stone fragments that migrate to areas inaccessible by rigid nephroscope 1
  • Normal saline irrigation must be used (not other solutions) to prevent electrolyte abnormalities 1
  • Nephrostomy tube placement after uncomplicated PCNL is optional ("tubeless PCNL") 1
• Contraindications include patients on anticoagulation/antiplatelet therapy that cannot be discontinued or those with anatomical deformities preventing proper positioning 1

Ureteroscopy (URS)

• Involves inserting a ureteroscope through the urethra and ureter to directly visualize and treat stones 2
• Can be performed with semi-rigid or flexible ureteroscopes depending on stone location 1
• Laser lithotripsy is preferred for flexible URS, while laser or pneumatic lithotripsy may be used with semi-rigid URS 1
• Safety wire should be used during the procedure 1
• Routine stent placement post-procedure is not necessary in uncomplicated cases 1

Shock Wave Lithotripsy (SWL)

• Uses shock wave energy generated outside the body to fragment stones 2
• Routine stenting before SWL is not recommended 1
• Success is highly dependent on factors such as obesity, skin-to-stone distance, collecting system anatomy, stone composition, and stone density 1
• Alpha-blockers may be prescribed after SWL to facilitate passage of stone fragments 1

Special Considerations

• For patients with obstructing stones and suspected infection, urgent drainage of the collecting system with a stent or nephrostomy tube is mandatory before definitive stone treatment 1
• In patients with negligible kidney function, nephrectomy may be considered 1
• For patients who cannot undergo PCNL, staged URS procedures may be offered as an alternative, though this may require multiple procedures and may not achieve complete stone clearance 1
• For patients who fail or are unlikely to have successful results with SWL or URS, alternative options include PCNL, laparoscopic, open, or robotic-assisted stone removal 1

Complications and Outcomes

• URS has higher stone-free rates compared to SWL (90% vs 72%) but slightly higher complication rates 1
• PCNL has the highest stone-free rates but also carries higher risks of bleeding and other complications 1
• Removal of even small asymptomatic stones during procedures for other stones can reduce future emergency department visits and need for additional surgeries 3

The choice of surgical approach should be based on stone characteristics, patient factors, and surgical expertise, with the goal of achieving stone-free status with minimal morbidity 4.