Evaluation of Preoperative Measurement of Stone Surface Area as a Predictor of Stone-Free Status After Combined Ureteroscopy with Holmium Laser Lithotripsy: A Single-Center Experience

Abstract

Stone volume and SA were highly indicative of stone status after single semirigid URS, with or without a flexible component. The formula for cSA, maximum diameter×width×π×1/4, was demonstrated to accurately represent SA in this study. SA, however, indicated a lower clinical priority and utility as a predictor of stone status than stone volume. The combination of semirigid and flexible URS could access any ureteral stones, including those that semirigid URS alone could not treat. The cutoff points for these predictors of outcome were 110.0 mm(2) for cSA, 125.0 mm(2) for tSA, and 840.0 mm(3) for stone volume.