Factors influencing the failure of extracorporeal shock wave lithotripsy with Piezolith 3000 in the management of solitary ureteral stone

Studies of predictive factors of extracorporeal shockwave lithotripsy (ESWL) failure in patients with ureteral stones have not yielded results sufficient to prevent ESWL failure. The present study investigated patients with ureteral stone and analyzed the predictive factors of ESWL failure. Ninety patients with ureteral stone treated from January 2006 to June 2012 using ESWL for ureteral stone were enrolled. Patient's demographic data including age, gender, body mass index (BMI), symptoms and calculous characteristics including location, size, episode and the grade of hydronephrosis were recorded. Statistical results were performed using univariate and multivariate analyses for the predictive factors of ESWL failure. In univariate analysis, calculous location, size, and grade of hydronephrosis between two groups displayed significant differences (p < 0.05). The predictive factors of ESWL failure were BMI > 25 kg/m(2) [Odds ratio (OR) = 3.5, 95 % confidence interval (CI) 1.1-11.0], calculous size a parts per thousand yen1 cm (OR = 10.5, 95 % CI 3.0-36.2), calculous location (mid-ureter; OR = 8.49, 95 % CI 1.5-45.7) and severe grade of hydronephrosis (OR = 12.3, 95 % CI 1.9-79.5). In conclusions, ESWL failure can be predicted in cases of obesity, calculous size exceeding 1 cm, mid-ureteral stone and severe hydronephrosis. When we consider calculous management in patients with these risk factors, initial surgical approach is recommended instead of ESWL.