Retrograde intrarenal surgery vs miniaturized percutaneous nephrolithotomy to treat lower pole renal stones 1.5-2.5 cm in diameter

Table 1 Stone characteristics and demographic data of patients

Characteristic	RIRS group	Mini-PCNL group	P value
Number	113	103
Age (yr)	49.59 ± 12.66	49.89 ± 13.09	0.864
Man (%)	67 (59.3)	75 (72.8)	0.051
BMI (kg/m2)	24.3 ± 3.21	23.24 ± 3.11	0.014
Side (right/left)	47/66	49/54	0.583
Stone size (mm)	18.27 ± 2.91	17.51 ± 5.29	0.218

Data presented are as means ± SD. BMI: Body mass index; PCNL: Percutaneous nephrolithotomy; RIRS: Retrograde intrarenal surgery.