Variables
Total (n = 621) Not stone-free (n = 125) Stone-free (n = 496)
P value
Age, years 46 (36-56) 44 (32.5-56) 46 (36-56) 0.174
Gender, n (%) Female Male 215 (34.6) 406 (65.4) 49(22.8) 76 (18.7) 166 (77.2) 330 (81.3)
0.229*
BMI, kg/m2 26.0 (24.0-28.6) 25.5 (23.5-27.5) 26.3 (24.2-29) 0.018
Side Left Right 334 (53.8) 287 (46.2) 64 (19.2) 61 (21.3) 270 (80.8) 226 (78.7)
0.517*
ASA category, n (%) ASA I ASA II ASA ≥ III 266 (42.8) 318 (51.2) 37 (6.0) 46 (17.3) 71 (22.3) 8 (21.6) 220 (82.7) 247 (77.7) 29 (78.4)
0.311*
Previous history of ESWL, n (%) 191 (30.8) 34 (27.2) 157 (31.7) 0.335*
Preoperative stent, n (%) 135 (21.7) 33 (26.4) 102 (20.6) 0.102*
Preoperative hydronephrosis, n(%) Grade 0
Grade 1-2
Grade 3-4
126 (20.3) 362 (58.3) 133 (21.4) 27 (21.4) 65 (18.0) 33 (24.8) 199 (78.6) 297 (82.0) 100 (75.2)
0.222*
Stone location, n (%)† 0.001*
Lower pole Middle pole Upper pole Pelvis Middle ureter Proximal ureter Multi-calyceal Ureter + Kidney 111 (17.9) 58 (9.3) 20 (3.2) 223 (35.9) 38 (6.1) 68 (11.0) 81 (13.0) 22 (3.5) 32 (28.8) a,b 11 (19.0) a,b,c,d 4 (20.0) a,b,c,d 27 (12.1) b,d 4 (10.5) a,b,c,d 6 (8.8) c,d 27 (33.3) a 6 (27.3) a,b,c,d 79 (71.2) a,b 47 (81.0) a,b,c,d 16 (80.0) a,b,c,d 196 (87.9) b,d 34 (89.5) a,b,c,d 62 (91.2) c,d 54 (66.7) a 16 (72.7) a,b,c,d
Stone location by T.O.HO., n (%)† Lower pole Middle pole Upper pole Proximal ureter (U1) Middle ureter (U2) 194 (31.2) 287 (46.2) 34 (5.5) 68 (11.0) 38 (6.1) 58 (29.9) a 51 (17.8) b 6 (17.6) a,b 6 (8.8) b 4 (10.5) b 136 (70.1) a 236 (82.2) b 28 (82.4) a,b 62 (91.2) b 34 (89.5) b
<0.001*
Stone number Single Multiple 512 (82.4) 109 (17.6) 88 (17.2) 37 (33.9) 424 (82.8) 72 (66.1)
<0.001&
Stone density, HU 897 (592-1230) 1050 (665-1313) 851 (572.5-1200) 0.006
Stone length, mm 16 (12-22.5) 25 (15.5-32) 15 (12-20) <0.001
Stone area, mm2 126 (77-204) 342 (141-573) 110 (66-175) <0.001
Operation time, min 75 (60-99) 100 (80.5-120) 70 (60-90) <0.001
Length of hospital stay, days 1 (1-2) 2 (1-3) 1 (1-2) <0.001
Complication rates, n(%) 66 (10.6) 21 (16.8) 45 (9.1) <0.019**
Complication grades, n(%) 0.038*
Grade 1-2 58 (9.3) 19 (15.2) 39 (7.9)
Grade 3-4 8 (1.3) 2 (1.6) 6 (1.2)
T.O.HO. score 7 (6-8) 8 (7-9.5) 7 (6-8) <0.001
STONE score Modified T.O.HO. score 10 (9-11) 6 (5-7) 11 (10-12) 8 (7-9) 10 (9-11) 6 (5-7) <0.001 <0.001