. 2025 Aug 21;25:212. doi: 10.1186/s12894-025-01912-6

Table 2.

Comparison of intraoperative and postoperative parameters according to stone impaction and degree of impaction

Variables	Non-impacted group	Impacted group	p-value	Degree of impaction				p-value
	Non-impacted group	Impacted group		Grade 1	Grade 2	Grade 3	Grade 4
	(n = 146)	(n = 65)		(n = 82)	(n = 64)	(n = 48)	(n = 17)
Operative time, (min), median (IQR)	15 (9.5)	25 (27)	< 0.001^m	15 (6)^a	15 (10)^a	25 (15)^{a, b}	50 (52.5)^b	< 0.001⁺
Pus discharge, n (%)	8 (5.5)	4 (6.2)	1.000^f	0 (0.0)^a	8 (12.5)^b	3 (6.3)^{a, b}	1 (5.9)^{a, b}	0.004^f
Double-J stenting, n (%)	141 (96.6)	65 (100)	0.327^f	77 (93.9)	64 (100.0)	48 (100.0)	17 (100.0)	0.071^f
Ureteral injury, n (%)	30 (20.5)	51 (78.5)	< 0.001*	15 (18.3)^a	15 (23.4)^a	36 (75.0)^b	15 (88.2)^b	< 0.001*
Degree of ureteral injury, n (%)			< 0.001^f					< 0.001^f
Grade 0	116 (79.5)	14 (21.5)		67 (81.7)^a	49 (76.6)^a	12 (25)^b	2 (11.8)^b
Grade 1	28 (19.2)	33 (50.8)		15 (18.3)^a	13 (20.3)^a	26 (54.2)^b	7 (41.2)^{a, b}
Grade 2	1 (0.7)	15 (23.1)		0 (0.0)^a	1 (1.6)^a	9 (18.8)^b	6 (35.3)^b
Grade 3 (perforation)	1 (0.7)	3 (4.6)		0 (0.0)^a	1 (1.6)^{a, b}	1 (2.1)^{a, b}	2 (11.8)^b
Treatment failure (nephrostomy placement), n (%)	0 (0)	4 (6.2)	0.008^f	0 (0.0)^a	0 (0.0)^a	0 (0.0)^a	4 (23.5)^b	< 0.001^f
Transient hematuria, n (%)	26 (17.8)	17 (26.2)	0.165*	16 (19.5)	10 (15.6)	13 (27.1)	4 (23.5)	0.493^f
Fever, n (%)	6 (4.1)	6 (9.2)	0.195^f	3 (3.7)	3 (4.7)	5 (10.4)	1 (5.9)	0.390^f
Hospital stay (days), median (IQR)	1 (0)	1 (0)	0.005^m	1 (0)^a	1 (0)^a	1 (0)^{a, b}	1 (1)^b	0.003⁺
Stone-free status, n (%)	126 (86.3)	40 (61.5)	< 0.001^*	73 (89)^a	53 (82.8)^a	34 (70.8)^{a, b}	6 (35.3)^b	< 0.001^f

IQR Interquartile range

*Pearson’s chi-square test, ^fFisher’s exact test, ^tIndependent-samples t-test, ^mMann-Whitney U test, ⁺Kruskal-Wallis test