2018 Volume 31 Issue 2 Pages 239-243
We retrospectively compared a group treated by only extracorporeal shock wave lithotripsy (SWL) with a group additionally treated by transurethral lithotripsy (TUL) for urinary tract stones. Between January 2012 and December 2017, ninety-four patients were initially treated by SWL and stone-free. “Stone-free” was defined as the situation that stones were completely removed or the residual fragments were ≦4mm. The age, sex, body mass index (BMI), stone location, Hounsfield units (HU), stone size, stone-surface area (SSA), existence of hydronephrosis before the operation, and skin-to-stone distance (SSD) were evaluated to determine the predictive factors for successful treatment by only SWL.
Thirty-two patients (34.0%), who were initially treated by SWL, needed to additional treatment with TUL. Univariate analysis of ninety-four patients showed that U1 stones ［U2-3 vs. U1 ; OR, 3.33 ; 95%CI, 1.37-8.35 ; p = 0.0075］, SSD ≦ 100 mm ［SSD ≧ 100 mm vs. SSD<100mm ; OR, 7.96 ; 95%CI, 2.49-35.70 ; p=0.0002］ were predictive factors for successful treatment by only SWL. Multivariate analysis of the ninety-four patients showed that “U1 stone”［U2-3 vs. U1 ; OR, 3.69 ; 95%CI, 1.42-10.13 ; p=0.0070］ and “SSD ≦100mm”［SSD≧100mm vs. SSD<100mm ; OR, 8.40 ; 95%CI, 2.51-39.20 ; p=0.0002］ were predictive factors for successful treatment by SWL. “U1 stones” and “SSD≦100mm” are effective to predict treatment success using only SWL based on the results of this study.
