The relationship between acoustic energy, stone burden, and stone clearance in biliary extracorporeal shock wave therapy (ESWL) is unclear. We hypothesized that there is a consistent relationship between these parameters that enables gallstone clearance to be predicted. Using a porcine model and various gallstone burdens, we performed biliary ESWL with varying energy levels and number of shock waves. The acoustic energy/stone burden ratio (AE/SB) was calculated that incorporated these variables. Stone clearance increased with higher energy settings and fewer stones present (p less than 0.005). The relationship between AE/SB ratio and stone clearance was logarithmic (r 2 = 0.82). The plateau of this curve showed optimal stone clearance at approximately 20 joules/g, beyond which point the benefit of further ESWL may not outweigh the risks. This relationship between AE/SB ratio and stone clearance may be able to predict the optimal energy required and probable outcome of biliary ESWL prior to the procedure.
|Original language||English (US)|
|Number of pages||6|
|Journal||The Journal of stone disease|
|State||Published - Apr 1993|