What is the best treatment option for a patient with a proximal ureteric stone causing mild-moderate hydronephrosis, considering flexible ureteroscopy or Extracorporeal Shock Wave Lithotripsy (ESWL)?

Treatment of Proximal Ureteric Stone with Mild-Moderate Hydronephrosis

For an 8.3 mm proximal ureteric stone with mild-moderate hydronephrosis, flexible ureteroscopy (URS) is recommended as the first-line treatment option due to its superior stone-free rate compared to ESWL. 1

Treatment Decision Algorithm

Stone Characteristics Assessment

• Stone size: 8.3 x 6.2 x 8.1 mm
• Stone location: Proximal ureter
• Stone density: 1300 HU (high density)
• Associated findings: Mild-moderate hydronephrosis, suggested ureteric kink

Treatment Options Comparison

Flexible Ureteroscopy (URS)

• Advantages:
  • Higher single-procedure stone-free rate (90% for URS vs 72% for ESWL) 1
  • Less affected by stone density and composition 1
  • Better option for stones with high density (>1000 HU)
  • Can address the underlying ureteric kink during the same procedure
  • Effective regardless of degree of hydronephrosis

Extracorporeal Shock Wave Lithotripsy (ESWL)

• Advantages:

  • Less invasive procedure with lower morbidity 1
  • Outpatient procedure with quicker recovery
  • No need for anesthesia in some cases

• Disadvantages:

  • Lower success rates for high-density stones (>1000 HU)
  • The stone's high density (1300 HU) significantly reduces ESWL efficacy
  • May require multiple sessions

Rationale for Recommendation

URS is the preferred treatment for this patient because:

1. The American Urological Association (AUA) guidelines recommend URS as first-line therapy for proximal ureteral stones requiring intervention, particularly when factors predict poor ESWL outcomes 2

2. The stone's high density (1300 HU) significantly reduces the likelihood of successful fragmentation with ESWL

3. The presence of a ureteric kink can be addressed during URS, which is not possible with ESWL

4. The presence of hydronephrosis does not negatively impact URS outcomes, whereas it might complicate ESWL treatment 3

5. URS has demonstrated excellent results for proximal ureteral stones with a high stone-free rate in a single procedure 4

Procedural Considerations

• Use of laser lithotripsy is preferred for flexible URS 1
• A safety wire should be employed during the procedure 1
• Routine pre-procedural stenting is not recommended 2, 1
• Post-procedure stenting may be omitted if:
  • No ureteric injury occurred during URS
  • No evidence of ureteric stricture
  • Normal contralateral kidney
  • No renal functional impairment
  • No planned secondary URS procedure 2

Follow-up Recommendations

• Follow-up imaging within 14 days to confirm stone clearance 1
• Metabolic evaluation to prevent recurrence, especially if this is a recurrent stone 1
• Increase fluid intake to achieve urine output of at least 2.5 liters daily 1

Common Pitfalls to Avoid

• Underestimating the impact of stone density on ESWL success
• Failing to consider anatomical factors (like the ureteric kink in this case) that may reduce ESWL efficacy
• Missing silent hydronephrosis during follow-up
• Not recognizing that even small residual fragments can cause symptoms or serve as nidus for future stone formation