What is the disposition for a patient with severe hydronephrosis due to a 5mm obstructing stone?

Management of Severe Hydronephrosis with 5mm Obstructing Stone

In patients with severe hydronephrosis due to a 5mm obstructing stone, urgent drainage of the collecting system is required, preferably with a ureteral stent or percutaneous nephrostomy tube, followed by definitive stone treatment once the infection is controlled. 1

Initial Management

Assessment of Infection Status

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

Urgent Decompression

• If infection is suspected with obstructing stone:
  • Urgent drainage of the collecting system is mandatory 1
  • Options include:
    1. Ureteral stent placement
    2. Percutaneous nephrostomy (PCN)
  • Both methods are effective for decompression 2
  • PCN may be superior for patients with high fever, especially males and younger patients 3

Antibiotic Management

• Start empiric antibiotics covering gram-positive and gram-negative uropathogens 4
• Obtain urine culture before starting antibiotics
• Continue antibiotics until clinical resolution and source control are achieved 4

Definitive Stone Management

Factors Affecting Treatment Choice

• Stone characteristics:
  • 5mm size: Borderline for spontaneous passage
  • Severe hydronephrosis: Indicates significant obstruction requiring intervention 1
  • Location: Proximal ureteral stones more likely to require intervention 5

Treatment Options

1. Ureteroscopy with Laser Lithotripsy

   • First-line treatment for obstructing stones with severe hydronephrosis 4
   • High stone-free rates (95% for stones <10mm) 4
   • Immediate resolution of obstruction
   • Can be performed after infection control

2. Shock Wave Lithotripsy (SWL)

   • Not recommended as first-line therapy for severe hydronephrosis 1
   • Lower success rates with hydronephrosis 6
   • Consider only after decompression and resolution of severe hydronephrosis

3. Percutaneous Nephrolithotomy (PCNL)

   • Generally reserved for larger stones (>20mm) 1
   • Not first-line for 5mm stone despite severe hydronephrosis

Follow-up Care

• Confirm stone clearance with appropriate imaging
• Send stone material for analysis to guide prevention strategies 4
• Consider metabolic evaluation to prevent recurrence
• Monitor for resolution of hydronephrosis

Common Pitfalls to Avoid

1. Delaying decompression in the setting of infection and obstruction

   • Can lead to urosepsis and increased morbidity/mortality 1

2. Attempting definitive stone treatment before controlling infection

   • Increases risk of septic complications 4

3. Relying solely on stone size for treatment decisions

   • Severe hydronephrosis with a 5mm stone indicates significant obstruction requiring intervention regardless of stone size 1, 7

4. Inadequate follow-up imaging

   • Essential to confirm stone clearance and resolution of hydronephrosis

The presence of severe hydronephrosis with a 5mm stone represents a potentially serious condition requiring prompt intervention to prevent renal damage and septic complications, even though 5mm stones might otherwise be candidates for observation and medical expulsive therapy in the absence of severe hydronephrosis.