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

Table 1

Comparison of measured demographic, clinical, stone, and operative variables between methods of extraction of stone fragments.

	AE	SE	value
Number of patients	109	87
Age, years	64 (20–90)	65 (24–89)	0.523
Sex
Female	48 (44%)	45 (52%)	0.284
Male	61 (56%)	42 (48%)
Side
Right	52 (48%)	39 (49%)	0.597
Left	57 (52%)	48 (51%)
Height (cm)	162 (139–180)	160 (128–181)	0.209
Body mass index (kg/m^2)	23.9 (15.4–37.9)	24.0 (15.7–33.9)	0.407
Number of stones	1 (1–7)	1 (1–10)	0.201
Stone volume (mm^3)	175.5 (0.175–4484)	249 (2.5–1830)	0.178
Cumulative stone diameter (mm)	10 (0.5–54)	13 (2–41)	0.051
Lower pole calculi ()	40 (37%)	34 (39%)	0.491
Number of calyx involving stone
0	59 (54%)	42 (48%)	0.716
1	34 (31%)	27 (31%)
2	11 (10%)	13 (15%)
3	5 (5%)	5 (6%)
Hounsfield Units
Maximum	1074 (152–1830)	1215 (284–1884)
Mean	751 (151–1671)	853 (134–1530)	0.554
Hydronephrosis ()	32 (29%)	31 (36%)	0.35
Access sheath (Fr)
13	9 (8%)	25 (29%)
14	35 (32%)	18 (21%)
15	65 (59%)	44 (56%)
Preoperative stenting ()	67 (61%)	47 (54%)	0.294
SWL failure ()	13 (12%)	8 (9%)	0.449
Operator’s experience of fURSL	15 (1–50)	11 (1–156)	0.075
Operative time (min)	85 (18–194)	80 (22–149)	0.182
Postoperative length of stay	2 (1–9)	2 (0–7)	0.115
Postoperative fever ()	20 (18%)	15 (17%)	0.306
Stone free (%)	61.5	90.8	<0.001
Stone composition
CaOX	77 (71%)	34 (39%)
CaP	3 (3%)	3 (3%)
UA	2 (2%)	3 (3%)
MAP	6 (6%)	14 (16%)
Mixed	17 (16%)	29 (33%)
other	1 (1%)	0 (0%)
unknown	3 (3%)	4 (5%)

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