The Effect of Renal Cysts on the Fragmentation of Renal Stones During Shockwave Lithotripsy: A Comparative In Vitro Study

Abstract Purpose: To assess the potential effect of simple renal cysts (SRC) on stone fragmentation during shockwave lithotripsy (SWL) in an in vitro model. Materials and 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 ...