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

Table 3

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

	Non-stone free	Stone free	value
Number of patients	43	66
Age (years)	67 (46–90)	61.5 (20–90)
Sex
Female	23 (53%)	25 (38%)	0.109
Male	20 (47%)	41 (62%)
Side
Right	21 (49%)	32 (48%)	0.971
Left	22 (51%)	34 (52%)
Height (cm)	162 (139–180)	161 (139–180)	0.47
Body mass index (kg/m^2)	23.3 (17.9–37.9)	24.4 (15.4–37.9)	0.401
Number of stones (n)	1 (1–7)	1 (1–3)
Stone volume (mm^3)	175.5 (0.175–4484)	120 (1.0–1989)	<0.001
Cumulative stone diameter (mm)	13 (4–54)	8 (0.5–26)	<0.001
Lower pole calculi ()	20 (47%)	20 (30%)	0.086
Number of calyx involving stone
0	16 (37%)	43 (65%)
1	17 (40%)	16 (24%)
2	6 (14%)	5 (8%)
3	4 (9%)	2 (3%)
Hounsfield Units
Maximum	1179 (366–1830)	973 (152–1780)	0.061
Mean	858 (354–1671)	684 (151–1516)	0.059
Hydronephrosis ()	12 (28%)	20 (30%)	0.788
Access sheath (Fr)
13	3 (7%)	6 (9%)	0.845
14	15 (35%)	20 (30%)
15	25 (58%)	40 (61%)
Preoperative stenting ()	30 (70%)	37 (56%)	0.151
SWL failure ()	3 (7%)	10 (15%)	0.198
Operator’s experience of fURSL	18 (1–50)	14 (2–40)	0.302
Stone composition
CaOX	31 (72%)	46 (70%)	0.752
CaP	1 (2%)	2 (3%)
UA	1 (2%)	1 (2%)
MAP	4 (9%)	2 (3%)
Mixed	5 (12%)	12 (18%)
other	0 (0%)	1 (2%)
unknown	1 (2%)	2 (3%)

AE: assistant extraction; CaP: calcium phosphate UA: uric acid MAP: magnesium ammonium phosphate; significant.