Comparison of the patients’ baseline characteristics between the stone-free and residual fragments subgroups in the percutaneous nephrolithotomy group
| Variable | SF (n=31) | RF (n=30) | p-value |
|---|---|---|---|
| Age (y) | 61.0 [50.0–64.0] | 53.5 [48.3-63.3] | 0.254a) |
| Gender Male Female |
18 (58.1) 13 (41.9) |
20 (66.7) 10 (33.3) |
0.488b) |
| BMI (kg/m2) | 23.7 [22.6-26.8] | 25.3 [22.0-27.5] | 0.564a) |
| Stone episodes First Recurrent |
19 (61.3) 12 (38.7) |
14 (46.7) 16 (53.3) |
0.252b) |
| Nephrostomy Absent Present |
6 (19.4) 25 (80.6) |
5 (16.7) 25 (83.3) |
0.785b) |
| Ureteral stent Absent Present |
28 (90.3) 3 (9.7) |
23 (76.7) 7 (23.3) |
0.182c) |
| Stone laterality Right Left Unilaterality Unilateral Bilateral |
6 (19.4) 25 (80.6) 31 (100.0) 0 (0.0) |
11 (36.7) 19 (63.3) 30 (100.0) 0 (0.0) |
0.132b) |
| Stone multiplicity Single Multiple |
18 (58.1) 13 (41.9) |
14 (46.7) 16 (53.3) |
0.373b) |
| Largest stone location Ureteropelvic junction Renal pelvis Upper calyx Mid calyx Lower calyx Staghorn |
1 (3.2) 13 (41.9) 1 (3.2) 9 (29.1) 0 (0.0) 7 (22.6) |
3 (10.0) 3 (10.0) 3 (10.0) 7 (23.3) 0 (0.0) 14 (46.7) |
0.021c) |
| Longest stone diameter (mm) | 25.0 [20.0-27.0] | 30.0 [20.0-46.3] | 0.015a) |
| Stone composition Calcium oxalate monohydrate Uric acid Struvite Brushite Mixed |
6 (19.4) 6 (19.4) 3 (9.6) 0 (0.0) 16 (51.6) |
5 (16.7) 3 (10.0) 1 (3.3) 1 (3.3) 20 (66.7) |
0.488c) |
| Tract size 18 Fr 24 Fr 30 Fr |
9 (29.0) 6 (19.4) 16 (51.6) |
5 (16.7) 4 (13.3) 21 (70.0) |
0.344c) |
The values are presented as median [interquartile range] or number (%)
In cases of multiple stones, the location and size of the stones were measured based on the largest stone
Statistically significant at p<0.05
BMI: body mass index, SF: stone-free, RF: residual fragments
a)Mann Whitney U test
b)Chi-square test
c)Fisher’s exact test