Table 3.

Comparison of overall application of mechanical lithotripsy according to the size of the stone in each group

	Group A (n = 27)		Group B (n = 28)
	< 2 cm (n = 14)	≥ 2 cm (n = 13)	< 2 cm (n = 15)	≥ 2 cm (n = 13)
Stone removal in the first session (%)	12 (85.7)a	11 (84.6)b	13 (86.6)c	10 (76.9)d
Mechanical lithotripsy (%)	2 (14.3)e	7 (53.8)f	2 (13.3)g	7 (53.8)h

Overall application of mechanical lithotripsy: 17/50 (34%). P value: a vs b, not significant; c vs d, not significant; e vs f, 0.018; g vs h, 0.008.