What is the best course of treatment for an 18-year-old woman with a stone at the ureteral orifice?

Management of Ureteral Stones at the Ureteral Orifice in an 18-Year-Old Woman

For an 18-year-old woman with a stone at the ureteral orifice, ureteroscopy (URS) with laser lithotripsy is the recommended first-line treatment due to its high stone-free rates (85-95%) and ability to provide immediate resolution of obstruction. 1

Initial Assessment and Treatment Options

Stone Size Considerations

• For stones ≤10mm at the ureteral orifice:
  • Initial observation with medical expulsive therapy (MET) using alpha-blockers may be appropriate
  • Spontaneous passage rates: ~62% for stones <5mm, ~35% for stones >5mm 1
  • Maximum observation period should not exceed 6 weeks to avoid irreversible kidney damage 1

First-Line Treatment

• Ureteroscopy (URS) with laser lithotripsy is recommended as first-line therapy for:
  • Stones that fail to pass with observation/MET
  • Stones causing severe symptoms or complications
  • Patients preferring immediate resolution 1

Alternative Treatment Options

• Shock wave lithotripsy (SWL) can be considered as an alternative for distal ureteral stones:
  • Stone-free rates of ~87% for stones <10mm 1
  • Less effective for dense stones or in obese patients
  • May require multiple sessions

Special Considerations for Young Female Patients

• In young patients, minimizing radiation exposure is critical:

  • Low-dose CT protocols should be used for diagnosis when imaging is needed 2
  • Ultrasound can be used for follow-up to reduce cumulative radiation exposure 3

• For female patients of reproductive age:

  • Consider potential impact on fertility if intervention is delayed
  • URS is preferred over SWL in women planning pregnancy in the near future 2

Procedural Details

Ureteroscopy Procedure

• Semi-rigid ureteroscope is typically sufficient for distal ureteral stones
• Holmium:YAG or thulium fiber laser for stone fragmentation
• Consider post-procedure stenting based on:
  • Degree of ureteral edema
  • Presence of ureteral injury during procedure
  • Residual stone fragments 1

Post-Procedure Care

• Follow-up imaging to confirm stone clearance
• Alpha-blockers may facilitate passage of small residual fragments
• Stone analysis to guide prevention strategies 1

Follow-Up and Prevention

• Metabolic evaluation recommended to identify risk factors for recurrence
• Increased fluid intake (>2L/day) to maintain dilute urine
• Dietary modifications based on stone composition
• Regular follow-up imaging to ensure complete stone clearance 1

Common Pitfalls to Avoid

1. Prolonged observation without intervention: Stones at the ureteral orifice can cause persistent obstruction leading to kidney damage if left untreated beyond 6 weeks

2. Inadequate pain management: Young patients may be undertreated for pain; ensure appropriate analgesia

3. Neglecting follow-up imaging: Confirmation of stone clearance is essential even after successful intervention

4. Overlooking metabolic evaluation: Young stone formers have high recurrence rates and benefit from comprehensive metabolic workup

5. Ignoring stone analysis: Stone composition guides preventive strategies and should be performed whenever possible

In summary, while observation with MET may be attempted initially for small stones, URS with laser lithotripsy represents the most definitive and effective treatment for an 18-year-old woman with a stone at the ureteral orifice, particularly if the stone is causing significant symptoms or obstruction.