Does previous failed ESWL have a negative impact of on the outcome of ureterorenoscopy? A matched pair analysis

This study aims to evaluate the outcome of ureteroscopy/ureterorenoscopy (URS) as a salvage procedure for stones resistant to extracorporeal shock wave lithotripsy (ESWL). Between January 2009 and January 2012, 313 patients with upper tract lithiasis were treated by URS. Among them, 87 (27.8 %) had undergone URS after prior ESWL failed to achieve stone clearance (Salvage group). These patients were matched with a group of patients who underwent URS as first-line modality (Primary group). Stone-free rates and adjuvant procedures represented the primary points for comparison. Secondary points for comparison included complications, procedure duration, total laser energy used and length of hospitalization. Matching was possible in all cases. Stone clearance rates were 73.6 and 82.8 % for the Salvage and Primary group, respectively. The difference in stone clearance rates between the two groups was not statistically significant (p = 0.186). A total of 11 patients (12.6 %) in the Primary group and 18 patients (20.7 %) in the Salvage group underwent an adjuvant procedure (p = 0.154). No statistically significant differences were noted in terms of complications, procedure duration and length of hospitalization. In the Primary group, the laser energy used for stone fragmentation was higher (p = 0.043). The rate of ureteric stenting at the end of the procedure was higher for the Salvage group (p = 0.030). Previous failed ESWL is not a predictor for unfavorable outcome of URS. Salvage URS is associated, however, with an increased need for ureteric stenting at the end of the procedure.