Is There a Difference in Outcomes Between Digital and Fiberoptic Flexible Ureterorenoscopy Procedures?

Purpose: We aimed to compare the outcomes of patients who were treated using digital and fiberoptic flexible ureterorenoscopy (URS) for kidney stones. Patients and Methods: Between September 2008 and December 2009, a total of 76 patients who were treated with either a conventional fiberoptic flexible ureterorenoscope (FFU) (n = 34) or digital flexible ureterorenoscope (DFU) (n = 42) were compared. All procedures were performed by the same surgeon. Preoperative, operative, and postoperative data were retrospectively analyzed. Results: The mean stone size was 95.2+/-61.3 mm(2) in the FFU group while it was 93.5+/-57.1 mm(2) in DFU group (P > 0.05). The initial assessment of the entire pyelocaliceal system was possible in 33 of 34 (97%) cases in the FFU group and in 38 of 42 cases (90.4%) in the DFU group (P>0.05). The mean operative time was significantly longer in the FFU group (54.4+/-14.8 minutes vs 44.8+/-17.9 minutes, P = 0.001). Flexible URS time was 46.5+/-13.4 minutes in the FFU group while it was 38.3+/-17.4 minutes in the DFU group (P = 0.001). Mean fragmented stone size per minute was 2.43+/-0.81 mm(2)/min in the DFU group and 1.96+/-0.80 mm(2)/min in the FFU group; this was statistically significant (P = 0.01). The overall stone-free rate 1 month after the procedure was 88.2% in the FFU group and 85.7% in the DFU group (P>0.05). The average number of uses for FFU and DFU before repair necessity was 17 and 21, respectively. Conclusion: Although the DFU have more limited maneuverability, comparable success rates can be achieved with both conventional and digital instruments. On the other hand, the DFU significantly reduced the operative time compared with the conventional one.