title: The Effect of Renal Cysts on the Fragmentation of Renal Stones During Shockwave Lithotripsy: A Comparative In Vitro Study.
abstract: OBJECTIVE
  To assess the potential effect of simple renal cysts (SRC) on stone fragmentation during shockwave lithotripsy (SWL) in an in vitro model.
  
  
  METHODS
  The in vitro model was constructed using 10% ordnance gelatin (OG). Models were created to mimic four scenarios: Model A-with an air-filled cavity (suboptimal for stone fragmentation); model B-without a cavity (normal anatomy); model C-with a 3-cm serum filled cavity (to represent a small SRC); model D-with a 4-cm serum filled cavity (to represent a larger SRC). SWL was applied to 24 standardized phantom stones (weight of 2±0.1 g) in each model using a standardized protocol. Stone fragments were retrieved, then dried overnight at room air temperature. Fragmentation coefficient (FC) was calculated for each stone, for fragments<4 mm and <2 mm.
  
  
  RESULTS
  The OG in vitro model was robust enough for the proposed research. There was no fragmentation evident in model A as expected. The mean FC was 29.7 (±20.5) and 39.7 (±23.7) for <4 mm fragments (P=0.069) and 7.6 (±4.1) and 10.6 (±6.7) for <2 mm fragments (P=0.047), for noncystic and cystic models, respectively. The mean FC was 29.7 (±20.5), 38.8 (±26.2) and 40.7 (±21.3) for <4 mm fragments (P=0.213) and 7.6 (±4.1), 11.1 (±8) and 10.2 (±5.3) for <2 mm fragments (P=0.138), for models B, C, and D, respectively.
  
  
  CONCLUSIONS
  Our in vitro experiment confirms better stone fragmentation associated with SWL in the presence of adjacent SRC.
authors.affiliation: 1 Division of Urology, Department of Surgery, Schulich School of Medicine and Dentistry, The University of Western Ontario , London, Ontario, Canada .
authors.forename: Husain
authors.initials: H
authors.lastname: Alenezi
authors.affiliation: 1 Division of Urology, Department of Surgery, Schulich School of Medicine and Dentistry, The University of Western Ontario , London, Ontario, Canada .
authors.forename: Daniel
authors.initials: D
authors.lastname: Olvera-Posada
authors.affiliation: 2 Department of Microbiology and Immunology, The University of Western Ontario , London, Ontario, Canada .|3 School of Health Sciences, Fanshawe College , London, Ontario, Canada .
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cadieux
authors.affiliation: 1 Division of Urology, Department of Surgery, Schulich School of Medicine and Dentistry, The University of Western Ontario , London, Ontario, Canada .
authors.forename: John D
authors.initials: JD
authors.lastname: Denstedt
authors.affiliation: 1 Division of Urology, Department of Surgery, Schulich School of Medicine and Dentistry, The University of Western Ontario , London, Ontario, Canada .
authors.forename: Hassan
authors.initials: H
authors.lastname: Razvi
mesh_terms: D003560:Cysts; D005780:Gelatin; D066298:In Vitro Techniques; D007669:Kidney Calculi / Q000628:therapy*; D052177:Kidney Diseases, Cystic; D008096:Lithotripsy / Q000379:methods*
chemical_list: D005780:Gelatin