Does preoperative hydronephrosis affect the stone-free rate of micro-percutaneous nephrolithotomy?

OBJECTIVES: Micropercutaneous nephrolithotomy (microperc) is a new minimal-invasive technique.We aimed to investigate whether preoperative hydronephrosis has an impact on the stone-free rate of microperc. METHODS: In this study, 66 consecutive patients were included and divided into 2 groups:patients without preoperative hydronephrosis (group-1) and patients with preoperative hydronephrosis (group-2).Both groups were compared for age, gender, body mass index (BMI), stone burden, stone location, fluoroscopy and operative time, blood loss, stone-free rate and perioperative and postoperative complication rates. Parameters were analyzed using univariate and multivariate analyses for the stone-free rate. RESULTS: The mean age, gender, BMI, stone location, and blood loss were similar in both groups (p > 0.05). Stone burden in group-2 was greater than group-1 (p=0.011). In addition, mean fluoroscopy time in group-1 was found to be significantly lower (p < 0.05). However, operative time was comparable among the groups (p=0.169). Lastly, group-2 had a higher rate of perioperative and postoperative complication rates and lower success rate (p=0.023, p=0.027 and p=0.001, respectively). The success was significantly affected by hydronephrosis, stone burden and location (p < 0.05). Logistic regression analysis revealed that unsuccessful outcome was significantly associated only with the presence of hydronephrosis (OR 0.225,p=0.033). CONCLUSION: This study seems to suggest that presence of hydronephrosis is a major factor on the stone free rate of microperc procedures.