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.

Table 2 Intraoperative and postoperative parameters and surgical complications in study groups

Variable	RIRS group	Mini-PCNL group	P value
Operative time (min)	56.48 ± 24.77	60.04 ± 30.38	0.345
Stone-free rate (postoperative 1 d) (%)	102/113 (90.2)	96/103 (93.2)	0.822
Stone-free rate (postoperative 2 mo) (%)	106/113 (93.8)	98/103 (95.1)	0.986
Hospital stay (d)	9.39 ± 4.01	14.08 ± 5.26	< 0.0001
No. of Clavien complications			0.643
Grade 0	89	76
Grade I	18	19
Grade II	6	7
Grade III	0	1
Grade IV/V	0	0
Preoperative Hb (g/dL)	137.12 ± 15.57	140.15 ± 16.04	0.161
Postoperative Hb (g/dL)	128.05 ± 16.87	125.34 ± 16.68	0.237
Hospitalization costs ($)	2624.5 ± 513.36	3255.2 ± 976.5	< 0.0001

Data are presented as mean ± SD. The P-value was adjusted by gender and BMI. Grade 0: No complication; Grade I: Any deviation from the normal postoperative course without the need for pharmacologic treatment or surgical, endoscopic and radiographic interventions, and acceptable therapeutic regimens are drugs such as antiemetics, antipyretics, analgetics, diuretics and electrolytes and physiotherapy; Grade II: Requiring pharmacologic treatment with drugs other than those allowed for grade I complications, blood transfusions and total parenteral nutrition are also included; Grade III: Requiring surgical, endoscopic, or radiographic intervention; Grade IV: Life-threatening complication requiring IC/ICU management; Grade V: Death of a patient due to a complication. PCNL: Percutaneous nephrolithotomy; RIRS: Retrograde intrarenal surgery.