The Analysis of Risk Factors for Hemorrhage Associated with Minimally Invasive Percutaneous Nephrolithotomy

Table 1

Patient demographics, stone characteristics, and surgical outcomes.

Variables	Mean (SD) or n / N	Median (range)
No. of patients (n)	396
Age (years)	42.5(13.1)	42.5 (12~73)
Male:female (n)	191 /205
BMI(kg/m^2)	24.7(2.6)	25.3 (18.3~29.6)
Right/left side (n)	186 /210	–
Stone size (mm^2)	617.3(266.5)	560 (230~1780)
Stone type
Staghorn	83 (21)
Renal pelvis	145 (36.6)
Calyceal	110 (27.8)
Upper ureter	58 (14.6)
Drop in hemoglobin
(g/dl)	2.19 (0.56)	2.23(0.94–5.69))

BMI = body mass index.