History of Ureteral Stenting Negatively Affects the Outcomes of Extracorporeal Shockwave Lithotripsy. Results of a Matched-pair Analysis.

To evaluate the impact of ureteral stenting history to the outcomes of extracorporeal shockwave lithotripsy, we retrospectively analysed patients who underwent shockwave lithotripsy with Dornier Gemini lithotripter between September 2010 and August 2012. Forty seven patients (group A) who had a double J stent which was removed just before the procedure were matched-paired with another 47 patients (group B) who underwent shockwave lithotripsy having no stent history. The correlation between ureteral stenting history and stone-free rates was assessed. Stone-free rates were 68.1% and 87.2% for patients of group A and B, respectively (p=0.026). Postoperative complications were not different between groups. Multivariate analysis revealed that stone size (p=0.007), stone location (p=0.044) and history of ureteral stenting (p=0.046) were independent predictors for stone clearance after shockwave lithotripsy. Ureteral stents adversely affect shockwave lithotripsy outcome, even if they are removed before the procedure. Stenting history should divert treatment plan towards intracorporeal lithotripsy.