What is the treatment approach for pediatric patients with urolithiasis (kidney stones)?

Treatment of Pediatric Urolithiasis

For pediatric patients with urolithiasis, initial management depends on stone size and location: offer observation with or without alpha-blockers for uncomplicated ureteral stones ≤10 mm, and proceed directly to ureteroscopy (URS) or extracorporeal shock wave lithotripsy (ESWL) for stones unlikely to pass spontaneously or when conservative management fails. 1

Initial Diagnostic Evaluation

Ultrasound is the primary imaging modality for suspected pediatric urolithiasis, with 45% sensitivity for ureteral stones and 94% specificity. 1 If ultrasound is non-diagnostic but clinical suspicion remains high (particularly with painful hematuria), proceed to low-dose non-contrast CT to assess stone location, size, density, and anatomy. 1 CT is especially valuable when ultrasound is negative but urolithiasis remains likely, as ultrasound detects only 38% of ureteral stones. 1

Obtain biochemical workup including urine dipstick and blood tests (creatinine, uric acid, ionized calcium, sodium, potassium, CRP) at presentation. 1 Perform 24-hour urine collection as the primary metabolic diagnostic test, as 76% of pediatric stone patients have at least one metabolic abnormality, most commonly hypocitraturia (52%) followed by hypercalciuria. 2

Emergency Management

Urgent decompression via percutaneous nephrostomy or ureteral stenting is mandatory within hours if sepsis, fever with obstruction, or anuria is present. 1, 3 Collect urine for culture before and after decompression, administer broad-spectrum antibiotics immediately, and delay definitive stone treatment until sepsis completely resolves. 1, 3

For renal colic pain, NSAIDs (diclofenac, ibuprofen, metamizole) are first-line analgesics, reducing need for additional analgesia compared to opioids. 1, 4 Use the lowest effective dose to minimize cardiovascular and gastrointestinal risks. 1, 4 Opioids (hydromorphone, pentazocine, or tramadol—avoid pethidine) serve as second-line agents when NSAIDs are contraindicated or insufficient. 1, 4

Conservative Management for Ureteral Stones ≤10 mm

Offer observation with or without medical expulsive therapy (MET) using alpha-blockers for uncomplicated ureteral stones ≤10 mm. 1 Spontaneous passage rates average 62% for distal ureteral stones <5 mm and 35% for stones >5 mm without treatment. 1

Alpha-blockers increase stone passage rates by 22-29%, reduce time to expulsion by approximately 3 days, and decrease pain episodes. 3, 4 Inform parents this is off-label use. 1 Limit conservative therapy to maximum 6 weeks from initial presentation to avoid irreversible kidney injury. 1

Recent evidence shows standardized MET protocols increase spontaneous passage rates (34% to 46%) and decrease surgical intervention rates (35% to 17%). 5

Surgical Intervention for Ureteral Stones

Offer URS or ESWL for pediatric patients unlikely to pass stones spontaneously or who fail observation/MET. 1 Selection depends on patient-specific anatomy and body habitus. 1

Stone-Free Rates:

• For stones <10 mm: URS achieves 95% stone-free rate vs. ESWL 87% 1
• For stones >10 mm: URS achieves 78% vs. ESWL 73% 1
• Overall ureteral stones: URS ~85% vs. ESWL 80-85% 1

URS has higher complication rates (12.4-20.5%) compared to ESWL (8-10%), but provides definitive single-procedure treatment. 1 ESWL is preferable in very small children or those with challenging anatomy (severe scoliosis, history of ureteral reimplantation) where ureteroscopic access is difficult. 1

Do not routinely pre-stent before URS, as upper tract access is possible on initial attempt in most children. 1 Pre-stenting is reserved for cases where initial access fails due to narrow ureterovesical junction. 1

Management of Renal Stones

For renal stones with total burden ≤20 mm, offer ESWL or flexible URS (FURS) as first-line therapy. 1 Recent meta-analysis shows FURS achieves significantly higher stone-free rates than ESWL in pediatric patients, with reassuringly similar complication rates. 1

Key Considerations:

• FURS provides single definitive procedure with stone-free rates of 60-100% 1
• **ESWL achieves 90% stone-free rate for stones <1 cm**, 80% for 1-2 cm stones, and 60% for stones >2 cm 1
• FURS has longer operative time and hospital stay (mean 0.6 days additional) but fewer repeat procedures 1
• No significant difference in complication rates or fluoroscopy exposure between modalities 1

Obtain low-dose CT prior to percutaneous nephrolithotomy (PCNL) for larger renal stones requiring this approach, adhering to ALARA principles. 1

Medical Prevention and Follow-up

Perform stone analysis for all first-time stone-formers to guide recurrence prevention. 1, 3 Stone recurrence occurs in approximately 39-40% of pediatric patients, necessitating long-term follow-up. 2

Medical treatment targets the specific metabolic abnormality:

• Hypocitraturia (most common): Potassium citrate supplementation 6, 2
• Hypercalciuria: Dietary sodium restriction, increased fluid intake 6, 7

High fluid intake is the cornerstone of prevention, along with dietary modifications based on stone composition and metabolic profile. 6, 7

Critical Pitfalls to Avoid

• Do not delay imaging in children with painful hematuria—proceed to CT if ultrasound is negative but clinical suspicion remains high 1
• Do not attempt definitive stone removal in presence of sepsis—decompress first, treat infection, then address stone 1, 3
• Do not exceed 6 weeks of conservative management to prevent irreversible renal damage 1
• Do not use NSAIDs in patients with low GFR due to renal function impact 1, 4
• Do not skip metabolic evaluation—76% have identifiable abnormalities requiring specific treatment 2