Comparison of long-term results following ureteroscopic stone fragmentation with removal versus stone dusting without removal

Purpose: To compare long-term results following ureteroscopic stone fragmentation and removal versus stone dusting. Methods: We conducted a retrospective analysis of patients who underwent ureteroscopy for renal calculi at two high-volume tertiary centres between 2012 and 2013, therefore allowing long-term follow-up. The surgeons differed in their technique, some performing dusting for the most part and the others fragmentation. Inclusion criteria were stone free at the first follow-up and the sole use of laser lithotripsy is either by dusting or by fragmentation. Operative and post-operative data as well as re-treatment rates were compared between the groups. Stone-free rates and long-term stone recurrence rates were analysed by a single radiologist blinded to the treatment technique. Results: Between 2012 and 2013, 669 ureteroscopies were performed at both centres. The study group included 100 patients, which met the inclusion criteria, equally distributed between dusting and fragmentation. The cumulative stone diameter in patients treated with dusting was significantly larger (12.7 mm versus 17 mm, p = 0.006). Operative time was shorter in patients treated with dusting (56 minutes versus 47.2 minutes, p = 0.6). The mean follow-up was 58.9 (standard deviation (SD) 17.2) and 69.4 (SD 13.8) months for the fragmentation and dusting-treated patients, respectively(p= 0.06). The long-term recurrence rate in the fragmentation group was 22% compared to 38% in the dusting group (p = 0 .08). Most of the patients in the dusting group required a repeat ureteroscopy during their follow-up (28% versus 6%, p = 0.003). A multivariable logistic regression analysis revealed that the fragmentation was not associated with a lower stone recurrence rate when compared to dusting (OR 0.6, 95% CI 0.199-1.810, p = 0.3). Conclusions: The recurrence rate of renal stones was not significantly influenced by the choice of surgical techniques. However, dusting was associated with a greater need for repeat ureteroscopy than fragmentation with removal.