Table 1.
Clinical data of the 576 patients.
| Variable | Value |
|---|---|
| Age, years, mean (SD) | 44.7 (13.6) |
| Stone size, cm, mean (SD) | 11.6 (5.2) |
| Gender, n (%) | |
| Male | 382 (66.3) |
| Female | 194 (33.7) |
| Stone laterality, n (%) | |
| Left | 309 (57.1) |
| Right | 267 (42.9) |
| Stone localization, n (%) | |
| Upper calyx | 74 (12.8) |
| Mid calyx | 112 (19.4) |
| Lower calyx | 167 (29.0) |
| Renal pelvis | 153 (26.6) |
| Multiple | 70 (12.2) |
| Presence of preoperative stent, n (%) | 53 (9.2) |
| Preoperative hydronephrosis, n (%) | |
| No | 428 (74.4) |
| Grade 1 | 95 (16.5) |
| Grade 2 | 40 (6.9) |
| Grade 3 | 13(2.2) |
| Achieved ffURS, n (%) | 557 (96.7) |