Retroperitoneal vs transperitoneal laparoscopic lithotripsy of 20-40 mm renal stones within horseshoe kidneys

Table 1 Demographic data of the included patients

	Retroperitoneal group (n = 7)	Transperitoneal group (n = 5)	P value
Age (yr)	37.29 ± 13.30	32.40 ± 15.24	0.567
Gender			1.000
Male, n (%)	3 (42.9)	2 (40.0)
Female, n (%)	4 (57.1)	3 (60.0)
Laterality			1.000
Left, n (%)	5 (71.4)	4 (80.0)
Right, n (%)	2 (28.6)	1 (20.0)
BMI (kg/m2)	21.69 ± 1.86	22.65 ± 2.43	0.457
Preoperative symptoms			0.559
Flank pain, n (%)	5 (71.4)	4 (80.0)
Abdominal pain, n (%)	1 (14.3)	1 (20.0)
Hematuria, n (%)	1 (14.3)	0 (0.0)
Preoperative infection			0.558
No, n (%)	5 (71.4)	2 (40.0)
Yes, n (%)	2 (28.6)	3 (60.0)
Hydronephrosis degree			1.000
≤ 1, n (%)	3 (42.9)	3 (60.0)
2, n (%)	4 (57.1)	2 (40.0)
Maximal stone diameter (mm)	26.71 ± 4.27	28.40 ± 4.04	0.507
Stone number			0.125
1, n (%)	4 (57.1)	2 (40.0)
2, n (%)	3 (42.9)	1 (20.0)
3, n (%)	0 (0.0)	2 (40.0)
Isthmus thickness (cm)	4.07 ± 1.10	4.18 ± 0.75	0.853
Operation time (min)	194.29 ± 102.48	151.40 ± 39.54	0.399
Estimated blood loss (mL)	48.57 ± 31.85	72.00 ± 41.47	0.292
Postop fasting time (d)	1.29 ± 0.49	2.40 ± 0.89	0.019
Hospital stay (d)	12.14 ± 2.61	12.40 ± 3.21	0.881
Minor complications, n (%)	1 (14.3)	1 (20.0)	1.000
Major complications, n (%)	0 (0.0)	0 (0.0)	N/A
eGFR [mL/(min·1.73 m2)]
Preoperative	143.00 ± 24.34	126.00 ± 40.48	0.383
Postoperative day 1	139.14 ± 23.97	123.80 ± 40.67	0.428
Postoperative day 30	139.71 ± 26.23	123.60 ± 39.42	0.398
Mean follow-up	29.42 ± 23.87	27.79 ± 21.75	0.906
SFR, n (%)	7 (100.0)	5 (100.0)	1.000

P values were calculated for intergroup comparisons using the Student’s t-test and Chi-square test. BMI: Body mass index; eGFR: Estimated glomerular filtration rate; SFR: Stone-free rate; N/A: Not applicable.

Table 2 Intergroup comparisons of postoperative estimated glomerular filtration rate change relative to preoperative levels

eGFR [mL/(min·1.73 m2)]	Retroperitoneal group (n = 7)	Transperitoneal group (n = 5)	P value
Postoperative day 1	-3.86 ± 0.69	-2.20 ± 2.17	0.176
Postoperative day 30	-3.29 ± 1.11	-2.40 ± 2.07	0.581

Values are expressed as mean ± SD. P values were calculated for intergroup comparisons using the Wilcoxon signed-rank test. eGFR: Estimated glomerular filtration rate.