title: A prospective, randomized trial of management for asymptomatic lower pole calculi.
abstract: OBJECTIVE
  We determined the natural course and compared the deleterious effects in kidneys of shock wave lithotripsy, percutaneous nephrolithotomy and observation for asymptomatic lower caliceal stones.
  
  
  METHODS
  Between April 2007 and August 2008 patients with asymptomatic lower caliceal calculi were enrolled in the study. To assess stone status noncontrast abdominal helical computerized tomography was done 3 and 12 months after intervention. All patients were evaluated by dimercapto-succinic acid renal scintigraphy 6 weeks and 12 months after intervention.
  
  
  RESULTS
  A total of 94 patients were prospectively randomized to percutaneous nephrolithotomy (31), shock wave lithotripsy (31) and observation (32). Mean +/- SD followup was 19.3 +/- 5 months (range 12 to 29). In the percutaneous nephrolithotomy group all patients were stone-free at month 12. Scintigraphy revealed a scar in 1 patient (3.2%) on month 3 followup imaging. In the shock wave lithotripsy group the stone-free rate was 54.8%. Scintigraphy revealed scarring in 5 patients (16.1%). In the observation group 7 patients (18.7%) required intervention during followup. Median time to intervention was 22.5 +/- 3.7 months (range 18 to 26). One patient (3.1%) had spontaneous stone passage. Scintigraphy did not reveal scarring in any patient.
  
  
  CONCLUSIONS
  Stone related events were noted in more than 20% of patients with asymptomatic lower caliceal stones observed expectantly. To manage lower caliceal stones percutaneous nephrolithotomy has a significantly higher stone-free rate with less renal scarring than shock wave lithotripsy. Thus, patients with asymptomatic lower caliceal stones must be informed in detail about all management options, especially focusing on percutaneous nephrolithotomy with its outstanding outcome.
authors.affiliation: Department of Urology, Haseki Teaching and Research Hospital and Department of Nuclear Medicine, Taksim Teaching and Research Hospital (EA), Istanbul, Turkey.
authors.forename: Emrah
authors.initials: E
authors.lastname: Yuruk
authors.forename: Murat
authors.initials: M
authors.lastname: Binbay
authors.forename: Erhan
authors.initials: E
authors.lastname: Sari
authors.forename: Tolga
authors.initials: T
authors.lastname: Akman
authors.forename: Erkan
authors.initials: E
authors.lastname: Altinyay
authors.forename: Murat
authors.initials: M
authors.lastname: Baykal
authors.forename: Ahmet Y
authors.initials: AY
authors.lastname: Muslumanoglu
authors.forename: Ahmet
authors.initials: A
authors.lastname: Tefekli
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D007670:Kidney Calices; D008096:Lithotripsy / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects; D011446:Prospective Studies; D055815:Young Adult