What is the treatment approach for kidney stones?

Treatment Approach for Kidney Stones

The treatment of kidney stones should be tailored based on stone size, location, and patient symptoms, with ureteroscopy (URS) being the first-line therapy for most ureteral stones due to its superior stone-free rates compared to shock wave lithotripsy (SWL). 1

Initial Assessment and Management

Symptomatic Management

• For acute renal colic:
  • Parenteral NSAIDs are as effective as narcotics for pain control 2
  • Adequate hydration to maintain urine output

Urgent Intervention

• For obstructing stones with suspected infection:
  • Urgent decompression of the collecting system with either percutaneous drainage or ureteral stent placement is mandatory 1
  • Delay definitive stone treatment until sepsis is resolved 1
  • Appropriate antibiotics based on urine culture and sensitivity 3

Treatment Algorithm Based on Stone Size and Location

Ureteral Stones

1. Stones ≤10 mm:

   • Conservative management with observation is appropriate 1
   • Medical expulsive therapy (MET) with α-blockers is recommended for distal ureteral stones 1
   • α-blockers increase stone passage rates from 54.4% to 77.3% compared to placebo 1
   • Maximum duration of conservative treatment: 4-6 weeks 1

2. Stones >10 mm or failed conservative management:

   • Distal ureteral stones: URS as first-line treatment 1
   • Proximal ureteral stones: URS is recommended as first-line treatment 1
   • SWL may be considered as an alternative option 1

Renal Stones

1. Stones ≤20 mm in renal pelvis or upper/middle calyx:

   • SWL or flexible URS are recommended first-line treatments 1
   • URS has higher single-procedure stone-free rates but SWL has lower morbidity 1

2. Lower pole stones:

   • ≤10 mm: SWL or flexible URS 1
   • 10-20 mm: Flexible URS or PCNL (percutaneous nephrolithotomy) 1, 3

3. Stones >20 mm (any location):

   • PCNL should be offered as first-line therapy 1
   • SWL should NOT be offered as first-line therapy for stones >20 mm 1
   • For stones 20-40 mm, staged flexible URS may be considered as an alternative 4
   • For stones >40 mm, miniaturized PCNL combined with flexible URS is preferred 4

Special Considerations

Infected Stones

• Complete stone removal is essential 5
• Preoperative antibiotics based on urine culture 3
• Ensure adequate drainage before definitive treatment 1

Stenting Considerations

• Routine stenting should not be performed in patients undergoing SWL 1
• Following URS, stenting may be omitted in uncomplicated cases 1
• If stent is placed, α-blockers and anti-muscarinic therapy may reduce stent discomfort 1

Prevention of Recurrence

Dietary Modifications

• Increase fluid intake to achieve urine output >2.5 L/day (target urine specific gravity <1.010) 3
• Maintain normal calcium intake (1,000-1,200 mg/day) 3
• Reduce sodium intake to <2,300 mg/day 3
• Moderate animal protein consumption (5-7 servings/week) 3
• Limit intake of high-oxalate foods (spinach, rhubarb, chocolate, nuts) 3

Medical Therapy

• For hypocitraturic patients:
  • Potassium citrate 30-80 mEq/day in divided doses 6
  • Increases urinary pH from 5.3 to 6.2-6.5 6
  • Increases urinary citrate to normal range 6
• For hyperuricosuria: Allopurinol 3
• For hypercalciuria: Thiazide diuretics 3

Follow-up and Monitoring

• Regular monitoring of urine pH (every 3-6 months initially, then annually if stable) 3
• 24-hour urine collection to evaluate metabolic parameters 3
• Stone analysis should be obtained at least once to guide preventive measures 3

By following this evidence-based approach to kidney stone management, patients can achieve optimal outcomes with minimal morbidity and reduced risk of recurrence.