What are the treatment options for renal stones?

Treatment Options for Renal Stones

The treatment of renal stones should be based on stone size, location, and patient symptoms, with options ranging from conservative management to surgical intervention depending on these factors. 1

Conservative Management

• For asymptomatic, non-obstructing caliceal stones, active surveillance is a viable option, especially for stones up to 15 mm 1
• Follow-up imaging is recommended to monitor for stone growth, which would indicate the need for intervention 1
• Spontaneous passage rates vary by stone size: 75% for stones <5 mm and 62% for stones ≥5 mm 1
• Medical expulsive therapy (MET) with alpha-blockers can be offered to facilitate stone passage, particularly for distal ureteral stones 1, 2

Indications for Active Stone Removal

• Stone growth during observation 1
• Symptomatic stones causing pain or obstruction 1
• Associated urinary tract infection 1
• Specific vocational reasons (e.g., pilots, frequent travelers) 1
• High risk of stone formation 1

Surgical Management Based on Stone Size and Location

Renal Stones ≤20 mm (Non-Lower Pole)

• Both shock wave lithotripsy (SWL) and ureteroscopy (URS) are acceptable first-line treatments 1
• URS is associated with higher single-procedure stone-free rates but has slightly higher complication rates 1
• URS may be preferred when quicker stone clearance is desired, as it has a lower likelihood of requiring repeat procedures 1

Renal Stones >20 mm

• Percutaneous nephrolithotomy (PCNL) should be offered as first-line therapy 1
• SWL should not be offered as first-line therapy due to significantly reduced stone-free rates and increased need for multiple treatments 1
• PCNL offers higher stone-free rates (94% vs. 75% for URS) and is less dependent on stone composition, density, and location 1

Lower Pole Stones

• For stones ≤10 mm: SWL or URS are recommended 1
• For stones 10-20 mm: URS or PCNL are preferred 1
• SWL may be considered for 10-20 mm lower pole stones if favorable conditions exist (broad infundibulo-pelvic angle, short infundibulum, etc.) 1

Procedural Considerations

Shock Wave Lithotripsy (SWL)

• Not recommended for stones >20 mm or for cystine staghorn calculi 1
• Routine pre-stenting is not recommended before SWL 1
• Alpha-blockers may be prescribed after SWL to facilitate passage of stone fragments 1
• Complications include fever (10.8%), need for transfusion (7%), and sepsis (0.5%) 1

Ureteroscopy (URS)

• Safety wire should be used during the procedure 1
• Laser or pneumatic lithotripsy may be used with semi-rigid ureteroscopes, while laser lithotripsy is preferred for flexible URS 1
• Routine stent placement is not recommended after uncomplicated URS 1
• Alpha-blockers and anti-muscarinics may be prescribed to reduce stent discomfort if stenting is required 1

Percutaneous Nephrolithotomy (PCNL)

• First-line therapy for stones >20 mm 1
• Tubeless PCNL (no nephrostomy tube) can be considered in uncomplicated cases to reduce pain and hospital stay 1
• Complications include fever (10.8%), transfusion (7%), thoracic complications (1.5%), and sepsis (0.5%) 1

Special Considerations

• In 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
• Nephrectomy may be considered when the involved kidney has negligible function 1
• For patients on antithrombotic therapy that cannot be discontinued, flexible URS is recommended 1

Prevention of Recurrence

• Increased fluid intake (2-3 liters per day) to maintain adequate urine output 2, 3
• Dietary modifications, particularly reduction in animal protein and salt intake 2
• Specific medical therapy based on stone composition and metabolic evaluation 4, 3

Remember that stone treatment should be tailored based on stone characteristics, available equipment, surgeon expertise, and patient preferences, with the goal of achieving stone-free status while minimizing morbidity.