Indications

These include:

• large stones:
  • calculi less than 0.4 cm usually pass spontaneously and can, in some cases, be observed
  • 50% of calculi between 0.4 cm and 0.6 cm pass spontaneously; intervention may be required
  • less than 10% of stones greater then 0.6 cm pass spontaneously; intervention is often necessary
• infection above the site of obstruction
• failure of conservative treatment
• evidence of renal impairment e.g. rising creatinine
• presence of anatomical abnormalities which predispose to stone formation