title: Endoscopic evidence of calculus attachment to Randall's plaque.
abstract: OBJECTIVE
  It has been proposed that calcium oxalate calculi begin as small stones attached to the renal papillae at sites of Randall's plaque. However, no study has investigated the prevalence of attached stones in calcium oxalate stone formers or the relationship between stone attachment site and Randall's plaque. In this study we used endoscopic examination of renal papillae in stone formers undergoing percutaneous nephrolithotomy to investigate both issues.
  
  
  METHODS
  Idiopathic calcium oxalate stone formers undergoing PNL for stone removal were enrolled in this study. Multiple papillae were examined and images were recorded by digital video. The presence or absence of papillary plaque and attached stones was noted, as was the site of stone attachment.
  
  
  RESULTS
  In 23 patients, 24 kidneys and 172 renal papillae were examined. All kidneys were found to have papillary plaque and 11 of the patients had attached stones. Most papillae (91%) contained plaque.
  
  
  CONCLUSIONS
  The prevalence of attached stones in calcium oxalate stone formers (48%) is greater than that previously reported for the general population. Attachment appears to be on Randall's plaque. The high prevalence of attached stones and the appearance of the attachment site are consistent with a mechanism of calcium oxalate stone formation in which stones begin as plaque overgrowth.
authors.affiliation: Methodist Hospital Institute for Kidney Stone Disease, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Matlaga
authors.forename: James C
authors.initials: JC
authors.lastname: Williams
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Kim
authors.forename: Ramsay L
authors.initials: RL
authors.lastname: Kuo
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Evan
authors.forename: Sharon B
authors.initials: SB
authors.lastname: Bledsoe
authors.forename: Fredric L
authors.initials: FL
authors.lastname: Coe
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Worcester
authors.forename: Larry C
authors.initials: LC
authors.lastname: Munch
authors.forename: James E
authors.initials: JE
authors.lastname: Lingeman
mesh_terms: D002129:Calcium Oxalate / Q000032:analysis; D004724:Endoscopy; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry / Q000473:pathology*; D007679:Kidney Medulla
chemical_list: D002129:Calcium Oxalate