Table 2.

Stratified peri-operative data

	n	Operation time(min)	Immediate SFR	SFR 30 days postoperative	multiple sessions	No. of basket(%)
Stone size
<2 cm	125	40.1 ± 22.4	84.8%	100.0%	0	31(24.8)*
2-3 cm	61	73.7 ± 28.9*	77.0%	100.0%	0	28(45.9)
>3 cm	38	157.5 ± 108.1*	50.0%*	84.2%*	10*	14(36.8)
Lower calyx involved
No	90	48.0 ± 42.7	88.9%	97.8%	2	6(6.7)
Yes	134	83.3 ± 73.5*	68.6%*	97.0%	8	67(50.0) *
Hounsfield Unit Value
≤1200Hu	146	58.9 ± 49.8	80.8%	98.6%	3	48(32.9)
>1200Hu	78	88.3 ± 84.0*	69.2%	96.1%	7*	25(32.0)

*P < 0.05