What are the indications for active stone removal based on European Association of Urology (EAU) guidelines?

Indications for Active Stone Removal Based on EAU Guidelines

Active stone removal is indicated for renal stones demonstrating stone growth or in patients at high risk of stone formation, and for ureteral stones when conservative management fails or complications arise. 1

Renal Stone Removal Indications

The 2025 EAU guidelines specify clear indications for removing renal stones 1:

• Stone growth on follow-up imaging 1
• High risk of stone formation (recurrent stone formers) 1

Important Context for Renal Stones

• Observation alone is problematic because spontaneous passage occurs in only 3–29% of cases, while symptoms develop in 7–77% of patients 1
• Stone growth occurs in 5–66% of cases, and 7–26% ultimately require surgery 1
• Active surveillance is not appropriate for stones >10 mm, as these have very low spontaneous passage rates 2

Ureteral Stone Removal Indications

Active removal of ureteral stones is indicated when conservative management (observation or medical expulsive therapy) is not appropriate or has failed 1. Specifically, intervention is required for:

Absolute/Urgent Indications

• Sepsis and/or anuria in an obstructed kidney (requires urgent decompression via percutaneous nephrostomy or ureteral stenting) 1
• Urinary tract infection with obstruction 2
• Intractable pain despite medical management 2
• Progressive hydronephrosis or declining renal function 2
• Solitary kidney or bilateral obstruction 2

Relative Indications

• Failure of conservative management after 4–6 weeks from initial presentation (to avoid irreversible kidney damage) 3
• Development of complications during conservative management, including infection, refractory pain, or decline in renal function 1
• Stones unlikely to pass spontaneously based on size and location 1

Conservative Management Limitations

The EAU guidelines establish when conservative management is NOT appropriate 1:

• Maximum conservative treatment duration is 4–6 weeks to prevent irreversible kidney injury 3
• Medical expulsive therapy (MET) should be stopped if complications arise 1
• Stones <5 mm pass in 75% of cases, compared to only 62% for stones ≥5 mm 1
• Distal stones <5 mm have an 89% passage rate, while upper ureteral stones <5 mm have a 75% passage rate 1

Critical Pitfalls to Avoid

• Never delay intervention beyond 4–6 weeks, as this can cause irreversible kidney injury 2
• Do not observe stones >10 mm expecting spontaneous passage 2
• Urgent decompression is mandatory before definitive stone treatment in septic or anuric patients 1
• Urine culture must be obtained before stone treatment to exclude or treat urinary tract infection 1, 3

Treatment Selection Algorithm

Once active removal is indicated, the EAU provides treatment algorithms based on stone location and size 1:

• For stones 10-20 mm: flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) are generally more effective than shock wave lithotripsy (SWL), particularly for lower pole locations 2
• For lower pole stones (10 mm): fURS or PCNL are first-line options, as SWL has lower stone-free rates 2
• For renal pelvis or upper/middle calyx stones (10 mm): fURS or SWL are equivalent first-line treatments 2