What is the treatment for a kidney stone that cannot pass?

Treatment for Kidney Stones That Cannot Pass

For kidney stones that cannot pass naturally, surgical intervention is required, with ureteroscopy (URS) and extracorporeal shock wave lithotripsy (ESWL) being the first-line treatment options, though the choice depends on stone characteristics, location, and patient factors. 1

Initial Assessment and Management

• In cases of sepsis and/or anuria due to an obstructed kidney, urgent decompression via percutaneous nephrostomy or ureteral stenting is strongly recommended before definitive treatment 1
• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac or ibuprofen are first-line treatments for pain management, with opioids as second-line options 1
• Medical expulsive therapy (MET) with α-blockers is recommended for stones ≤10 mm in the distal ureter, but is generally ineffective for stones that are already determined to be unable to pass 1, 2

Surgical Treatment Options

Extracorporeal Shock Wave Lithotripsy (ESWL)

• Appropriate for stones that cannot pass but are accessible to shock waves 1
• Contraindicated in pregnancy, bleeding disorders, uncontrolled UTIs, severe obesity, skeletal malformations, arterial aneurysms near the stone, or anatomic obstructions distal to the stone 1
• Best practices include:
  • Decreasing frequency from 120 to 60-90/min improves stone-free rates and reduces tissue damage 1
  • Proper acoustic coupling between treatment head and skin is crucial 1
  • Experienced operators achieve better outcomes 1

Ureteroscopy (URS)

• Highly effective for stones that cannot pass, with better stone-free rates than ESWL for most stone locations 1
• No specific contraindications aside from general anesthesia risks and untreated UTIs 1
• Can be safely performed in patients with bleeding disorders or those who cannot interrupt anticoagulation therapy 1
• Complications include ureteral injury (3-6%), stricture formation (1-4%), and infection (2-4%) 1

Percutaneous Nephrolithotomy (PCNL)

• Standard treatment for large renal stones that cannot pass 1
• Associated with higher complication rates than other methods, including fever (10.8%), transfusion (7%), thoracic complications (1.5%), and sepsis (0.5%) 1
• Mini-PCNL (12-22 F) reduces blood loss and hospital stay compared to standard PCNL (>22 F) 1

Stone-Specific Considerations

Uric Acid Stones

• Oral chemolysis with potassium citrate to alkalinize urine (target pH 6.0) is strongly recommended 1
• Allopurinol should not be routinely offered as first-line therapy 1

Cystine Stones

• Potassium citrate to raise urinary pH to 7.0 1
• Cystine-binding thiol drugs (e.g., tiopronin) for patients unresponsive to dietary modifications and urinary alkalinization 1

Struvite Stones

• Complete surgical removal is necessary 1
• Urease inhibitors may be beneficial despite side effects 1

Post-Treatment Management

• Routine stenting after uncomplicated URS is unnecessary but recommended in cases with trauma, residual fragments, bleeding, perforation, or UTI 1
• Alpha-blockers improve stent tolerability 1
• Follow-up imaging to confirm stone clearance 1
• Metabolic evaluation to prevent recurrence, including 24-hour urine collection within six months of treatment 1

Decision Algorithm for Stones That Cannot Pass

1. Emergency situations: If sepsis or anuria is present, immediate decompression via nephrostomy or stenting 1

2. For ureteral stones:

   • First-line: URS for patients with bleeding disorders or on anticoagulation 1
   • For others: Either URS or ESWL based on stone location and size 1
   • URS has higher stone-free rates but slightly higher complication rates 1

3. For renal stones:

   • Small to medium stones (<20 mm): ESWL or flexible URS 1
   • Large stones (>20 mm): PCNL is the standard treatment 1

4. For specific stone compositions:

   • Uric acid stones: Consider oral chemolysis with surgical intervention if needed 1
   • Cystine and struvite stones: Typically require surgical intervention 1

Prevention of Recurrence

• Increased fluid intake to maintain urine output >2L/day 2, 3
• Dietary modifications based on stone type 3, 4
• Medications such as thiazide diuretics and/or potassium citrate for recurrent calcium stones 1
• Regular follow-up with 24-hour urine specimens to monitor treatment effectiveness 1