Comparison of Outcomes between Two Methods to Extract Stone Fragments during Flexible Ureteroscopic Lithotripsy

Table 4

Comparison of measured demographic, clinical, stone, and operative variables between patients with a stone-free and a non-stone-free postoperative status for the SE group.

	Non-stone free	Stone free	value
No. of patients	8	79
Age (years)	56 (24–82)	65 (24–89)	0.16
Sex
Female	3 (38%)	42 (53%)	0.398
Male	5 (63%)	37 (47%)
Side
Right	2 (33%)	37 (47%)	0.237
Left	6 (67%)	42 (53%)
Height (cm)	170 (143–180)	160 (128–181)	0.095
Body mass index (kg/m^2)	23.5 (17.4–26.5)	24.0 (15.7–33.9)	0.467
Number of stones ()	2.5 (1–10)	1 (1–10)	0.082
Stone volume (mm^3)	276 (123–735)	249 (2.47–1830)	0.78
Cumulative stone diameter (mm)	17.8 (7.8–26)	13 (2–41)	0.056
Lower pole calculi ()	5 (63%)	29 (37%)	0.002^*
Number of calyx involving stone
0	2 (25%)	40 (51%)	0.061
1	2 (25%)	25 (32%)
2	2 (25%)	11 (14%)
3	2 (25%)	3 (4%)
Hounsfield Units
Maximum	1197 (510–1606)	1228 (284–1884)	0.994
Mean	899 (382–1251)	821 (134–1530)	0.681
Hydronephrosis ()	1 (13%)	30 (38%)	0.152
Access sheath (Fr)
13	1 (13%)	24 (30%)	0.567
14	2 (25%)	16 (20%)
15	5 (63%)	39 (49%)
Preoperative stenting ()	3 (38%)	44 (56%)	0.325
SWL failure ()	1 (13%)	7 (9%)	0.9
Operator’s experience of fURSL	6 (1–155)	11 (1–156)	0.154
Stone composition
CaOX	4 (50%)	30 (38%)	0.65
CaP	0 (0%)	3 (4%)
UA	1 (13%)	2 (3%)
MAP	1 (13%)	13 (16%)
Mixed	2 (25%)	27 (34%)
other	0 (0%)	0 (0%)
unknown	0 (0%)	4 (5%)

SE: surgeon extraction; CaP: calcium phosphate UA: uric acid MAP: magnesium ammonium phosphate; significant.