Incidence and risk factors for urolithiasis recurrence after endourological management of kidney stones: A retrospective single-centre study.

INTRODUCTION: Almost half of the patients have had recurrent nephrolithiasis despite undergoing effective treatment. Our objective is to determine the recurrence rate of lithiasis after endourological management of nephrolithiasis and identify the risk factors for these recurrences. METHODS: Data were gathered retrospectively from all patients who were treated for nephrolithiasis by endourological management from May 2014 to January 2017 in our university hospital. The patients were devised into two groups: with and without recurrence. Many variables were also compared between these two groups. RESULTS: During this period 265 patients were treated for upper urinary tract stone. A total of 190 patients were included in the study. The median age and median BMI of the patients were 57.5 years and 25.2kg/m2, respectively. A biochemical analysis of the stones was performed in 117 (61.5%) patients. The most common types of stones were calcium oxalate monohydrate stones (n=44, 23.2%), mixed stones (n=39, 20.5%) including mixed calcium oxalate (n=10; 8.5%), calcium oxalate dihydrate stones (n=13, 6.8%) and uric acid stones (n=11, 5.8%). At the end of a median follow-up of 32 months (range, 13-61 monthes), 49 patients (25.8%) had a recurrent stone. In univariate analysis, the risk factors for recurrence were BMI greater than 25kg/m2 (HR: 2; P<0.05), diabetes (HR: 3.73; P<0.008) and smoking (HR: 3.1; P<0.039). However age (HR: 0.96: P<0.003) and high blood pressure (HR: 0.37; P<0.027) were protective factors. In multivariate analysis, diabetes, smoking, hypertension, and age are still risk factors for recurrence. CONCLUSION: Stone recurrence is common after the management of urinary stones. In this study 25.8% of patients had recurred stone disease after endourological management with a median follow-up of 32 months. Our study findings showed that diabetes and smoking are risk factors for recurrence, while age and blood hypertension are protective factors that decreased the risk of recurrence.