What is the management approach for a patient with a renal stone and hydronephrosis?

Management of Renal Stones with Hydronephrosis

For patients with renal stones and hydronephrosis, the initial management approach should be retrograde ureteral stenting followed by definitive ureteroscopic stone extraction, as this provides the most effective decompression with lower complication rates and shorter hospital stays compared to percutaneous nephrostomy. 1

Initial Assessment and Imaging

• Non-contrast CT scan is the gold standard for diagnosis of renal stones and assessment of hydronephrosis, providing accurate information about stone size, location, and degree of obstruction 1
• Ultrasound can be used as an initial screening tool, especially in pregnant patients or those who cannot undergo CT, but has lower sensitivity (52-57%) for detecting renal stones compared to CT 1, 2
• The severity of hydronephrosis on imaging correlates with clinical outcomes and helps guide management decisions 3, 2

Management Algorithm Based on Clinical Presentation

For Patients with Hydronephrosis and Signs of Infection/Sepsis:

1. Immediate decompression of the collecting system is mandatory 1

2. Preferred approach: Retrograde ureteral stenting

   • Associated with decreased hospital stay and ICU admission rates compared to PCN 1
   • Technical success rates of approximately 80% 1
   • May be associated with higher documented fever rates 1

3. Alternative: Percutaneous nephrostomy (PCN) if:

   • Retrograde stenting fails 1
   • Patient is at high risk for anesthesia 1
   • Pyonephrosis is present requiring larger tube decompression 1
   • Technical success rates approach 100% 1

4. Antegrade ureteral stenting may be considered if retrograde stenting fails, but requires careful monitoring due to risk of worsening sepsis 1

For Patients with Hydronephrosis without Infection:

1. Stone size <10 mm:

   • Trial of spontaneous passage with medical expulsive therapy (MET) may be appropriate 1
   • Patient must have well-controlled pain, no sepsis, and adequate renal function 1
   • Regular imaging follow-up to monitor stone position and hydronephrosis 1

2. Stone size >10 mm:

   • Surgical intervention is typically required 1
   • Options include:
     • Extracorporeal shock wave lithotripsy (SWL) - effectiveness not affected by presence or degree of hydronephrosis 4
     • Ureteroscopy (URS) - higher stone-free rates but slightly higher complication rates 1

Definitive Stone Management After Initial Decompression

• For patients initially treated with retrograde stenting:

  • Ureteroscopic stone extraction is typically performed as definitive treatment 1
  • Higher stone-free rates with a single procedure compared to SWL 1

• For patients initially treated with PCN:

  • Percutaneous nephrolithotomy may be preferred, especially for larger stone burden 1
  • Antegrade stone removal can be performed through the established nephrostomy tract 1

Special Considerations

• Pregnant patients: Ultrasound-guided decompression is preferred to minimize radiation exposure; retrograde stenting can be performed with minimal or no fluoroscopy 1
• Severe infected hydronephrosis: May require more aggressive decompression; in rare cases with very large, complex stones, open surgery may still be considered 5
• Moderate to severe hydronephrosis: Associated with higher rates of passage failure (28-43%) compared to mild or absent hydronephrosis (15-20%) 3

Complications to Monitor

• SWL complications: Sepsis (3-5%), steinstrasse (4-8%), stricture (0-2%) 1
• URS complications: Sepsis (2-4%), ureteral injury (3-6%), stricture (1-4%) 1
• PCN complications: Major complication rate approximately 4%, including bleeding, infection, and tube dislodgement 6

Follow-up Recommendations

• Regular imaging to assess stone position and resolution of hydronephrosis 1
• Patients with absent or mild hydronephrosis have lower passage failure rates and may be appropriate for conservative management 3, 2
• Severe hydronephrosis warrants definitive imaging and urological referral 3