What is the first line of treatment for renal stones?

First-Line Treatment for Renal Stones

The first-line treatment for renal stones depends on stone size, location, and symptoms, with conservative management recommended for uncomplicated stones ≤10mm, while surgical intervention is indicated for larger stones or those causing obstruction with infection. 1

Treatment Algorithm Based on Stone Characteristics

Asymptomatic Renal Stones

• ≤15mm non-obstructing caliceal stones: Active surveillance with follow-up imaging 1
• Indications for intervention despite being asymptomatic: Stone growth, associated infection, or specific situations such as vocational reasons 1

Symptomatic Renal Stones

Non-Lower Pole Stones

• ≤20mm: SWL (shock wave lithotripsy) or URS (ureteroscopy) 1
  • URS associated with lower likelihood of repeat procedures 1
  • Stone-free rates for both are acceptable with less morbidity than PCNL 1
• >20mm: PCNL (percutaneous nephrolithotomy) as first-line therapy (Strong Recommendation; Evidence Strength: Grade C) 1
  • PCNL offers higher stone-free rate (94% vs 75% for URS) 1
  • Success rate less dependent on stone composition, density, and location 1
  • SWL should NOT be offered as first-line therapy for stones >20mm 1

Lower Pole Stones

• ≤10mm: SWL or URS (Strong Recommendation; Evidence Strength: Grade B) 1
  • No significant difference in stone-free rates between URS and SWL 1
• >10mm: URS or PCNL (NOT SWL) (Strong Recommendation; Evidence Strength: Grade B) 1
  • For 10-20mm stones: Median success rate of 58% for SWL vs 81% for URS and 87% for PCNL 1
  • For >20mm stones: SWL success rate declines to 10% 1

Ureteral Stones

• ≤10mm distal ureteral stones: Medical expulsive therapy (MET) with α-blockers as first-line treatment 1, 2
• >10mm distal ureteral stones: URS as first-line treatment 1
• Proximal ureteral stones (all sizes): URS recommended as first surgical modality 1

Special Considerations

Obstructing Stones with Suspected Infection

• URGENT drainage of collecting system with stent or nephrostomy tube (Conditional Recommendation; Evidence Strength: Grade C) 1
• Delay stone treatment until infection is controlled 1

Factors Affecting Treatment Selection

• SWL success factors: Stone density/attenuation, obesity, skin-to-stone distance, collecting system anatomy 1
• Contraindications to PCNL: Use of anti-coagulation/anti-platelet therapy that cannot be discontinued, anatomical deformities preventing proper positioning 1

Post-Procedure Management

• Routine stent placement after uncomplicated URS is not recommended 1
• α-blockers and anti-muscarinic therapy may be offered to reduce stent discomfort if stents are placed 1

Common Pitfalls to Avoid

1. Delaying treatment of obstructing stones with infection - This requires urgent drainage to prevent sepsis
2. Using SWL for lower pole stones >10mm - Significantly reduced success rates compared to URS or PCNL
3. Offering SWL for stones >20mm - Poor outcomes and increased need for multiple treatments
4. Neglecting metabolic evaluation - All stone patients need metabolic evaluation to prevent recurrence 3

By following this evidence-based algorithm, clinicians can optimize outcomes for patients with renal stones while minimizing morbidity and the need for repeat procedures.