Time-dependent oxidative stress effects of percutaneous nephrolithotomy

Aim of this study was to investigate the effects of operation time of percutaneous nephrolithotomy (PCNL) on renal function and hemodynamic response. Thirty-four patients (14 male, 20 female) with normal renal function who underwent unilateral single-tract PCNL between December 2010 and June 2011 were included in the study. The age, sex, stone size, grade of hydronephrosis, operative time, access pole, shock number of lithotripter, complications, stone-free rate, and hemodynamic parameters during operation were recorded. Total blood count and oxidative stress parameters such as paraoxonase 1 (PON1), total antioxidant status (TAS), total oxidant status (TOS), and malonyldialdehyde (MDA) levels were examined before the operation as baseline levels and then at 30, 60, 90, and 120 min during the operation. The mean age of the patients was 31.4 ± 18.8 (9–66 years) years. Mean stone size was 35.5 ± 15.6 mm. Mean serum BUN and creatinine did not change postoperatively (p > 0.05), whereas mean WBC and 24-h urine cortisol were positively and hematocrite were negatively changed significantly (p < 0.05). Oxidative stress parameters such as PON1 and TAS showed statistically significant decreases, while TOS and MDA showed statistically significant increases with increased operation time, especially after 1 h (p < 0.005). A bivariate correlation test showed correlation between oxidative stress parameters and operation time (p = 0.002), but no correlation was found between oxidative stress parameters and other parameters (p > 0.05). Oxidative stress and response to it increased with increasing operative time during a PCNL procedure, especially after 1 h. Further studies with a larger and longer series should be performed to clarify this issue further.