What is the treatment for an obstructing stone with hydroureteronephrosis?

Treatment for Obstructing Stone with Hydroureteronephrosis

For obstructing stones with hydroureteronephrosis, urgent drainage of the collecting system is required through either ureteral stent placement or percutaneous nephrostomy (PCN), followed by definitive stone treatment once the patient is stabilized. 1

Initial Management

Assessment for Infection

• Evaluate for signs of infection:
  • Fever, chills
  • Elevated white blood cell count
  • Abnormal urinalysis
  • Systemic inflammatory response syndrome (SIRS)

Urgent Decompression Options

1. Retrograde Ureteral Stenting:

   • First-line approach in most cases
   • Technical success rate around 80% 2
   • Benefits: Lower number of subsequent interventions, decreased hospital stay, and lower ICU admission rates compared to PCN 2
   • Caution: May be associated with higher risk of documented fever 2

2. Percutaneous Nephrostomy (PCN):

   • Technical success rate approaches 100% 2
   • Preferred in specific scenarios:
     • Failed retrograde stenting
     • Patients at high risk for anesthesia
     • Pyonephrosis requiring larger tube decompression
     • Patients too ill for definitive stone treatment 2
   • Shorter dwell time compared to ureteral stents 2

3. Percutaneous Antegrade Ureteral Stenting:

   • Consider if retrograde stenting fails
   • Risk: Prolonged manipulation can increase urosepsis risk
   • Requires close monitoring during and after procedure 2

Definitive Stone Treatment Options

After successful decompression and control of infection (if present):

1. Ureteroscopy with Laser Lithotripsy:

   • First-line treatment for most ureteral stones
   • Provides immediate resolution of obstruction
   • High stone-free rates 1
   • Patients treated with double-J stents typically receive ureteroscopic approach 2

2. Percutaneous Nephrolithotomy (PCNL):

   • Consider for larger stones (>20mm)
   • Can be performed as a primary procedure in selected cases
   • A randomized trial showed similar complication rates but shorter hospital stays compared to PCN followed by delayed treatment 2
   • Patients initially treated with PCN often receive percutaneous approach for definitive treatment 2

3. Extracorporeal Shock Wave Lithotripsy (SWL):

   • Not recommended as first-line for severe hydronephrosis
   • Consider after decompression and resolution of severe hydronephrosis
   • Less effective for larger stones (>16mm) 3
   • Mean clearance time increases with stone size: 2.2 days for 5-10mm stones vs. 12.2 days for stones ≥16mm 3

Special Considerations

Pregnant Patients

• Hydronephrosis is common after 20 weeks of pregnancy
• Medical management (rest, hydration, analgesia) has 70-80% success rate for stone passage 2
• If intervention needed:
  • Retrograde stenting preferred with minimal/no fluoroscopy
  • PCN if stenting fails, can be performed with ultrasound guidance 2

Patients with Infection

• Mandatory urgent drainage if infection with obstruction
• Administer antibiotics until clinical resolution and source control achieved 1
• Monitor closely for signs of sepsis
• Avoid common pitfalls:
  • Prolonged antibiotic courses without clear indication
  • Failing to obtain cultures before starting antibiotics
  • Not establishing drainage in infected obstructed systems 1

Follow-up

• Imaging to confirm stone clearance
• Consider alpha-blockers to facilitate passage of small residual fragments
• Metabolic evaluation to identify risk factors for recurrence
• Stone analysis to guide preventive measures 1

Complications of Delayed Treatment

• Progressive renal damage
• Kidney shrinkage in cases of chronic obstruction 4
• Worsened renal function and increased morbidity 1

The evidence strongly supports that prompt intervention with decompression followed by definitive stone treatment provides the best outcomes for patients with obstructing stones causing hydroureteronephrosis.