title: Clinical implications of clinically insignificant store fragments after extracorporeal shock wave lithotripsy.
abstract: OBJECTIVE
  We determined the natural history and clinical significance of small, asymptomatic, noninfection related stone fragments after extracorporeal shock wave lithotripsy (ESWL).
  
  
  METHODS
  We prospectively followed 160 patients with 4 mm. or less asymptomatic calcium oxalate/phosphate stone fragments after ESWL for 1.6 to 88.8 months (mean 23) to stone-free status, censorship or intervention. Kaplan-Meier estimates of probability to anatomical stone-free, decreased or stable status were determined as well as the probability of symptomatic episodes or required urological intervention.
  
  
  RESULTS
  Stone-free status or a decreased, stable or increased amount of residual stone occurred in 38 (23.8%), 26 (16.3%), 67 (41.9%) and 29 (18.1%) of the 160 patients, respectively. At 5 years after ESWL the probability of a stone-free, stone-free or decreased status, or stone-free, decreased or stable status was 0.36, 0.53, and 0.80, respectively. A total of 91 patients (56.9%) remained asymptomatic while 69 (43.1%) had a symptomatic episode or required intervention 1.6 to 85.4 months (mean 26) after ESWL (probability estimated at 0.71 at 5 years).
  
  
  CONCLUSIONS
  While patients with small noninfection related stone fragments after ESWL may be followed expectantly, a significantly number will require intervention or have symptomatic episodes within 2 years. The term clinically insignificant applied to any residual stone after ESWL is likely a misnomer.
authors.affiliation: Department of Urology, Cleveland Clinic Foundation, Cleveland, Ohio, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Streem
authors.forename: A
authors.initials: A
authors.lastname: Yost
authors.forename: E
authors.initials: E
authors.lastname: Mascha
mesh_terms: D005260:Female; D006801:Humans; D008096:Lithotripsy / Q000009:adverse effects; D008297:Male; D011446:Prospective Studies; D012008:Recurrence; D013997:Time Factors; D014545:Urinary Calculi / Q000628:therapy*