Urinary stone analysis on 12,846 patients: a report from a single center in China

We reported a retrospective review of the urinary stone compositions in 12,846 patients. Data on urinary stone compositions analyzed between January 2003 and December 2012 in our center were collected. Infrared spectroscopy was used for stone analysis. Predominant stone component was recorded. Patients were divided into four age groups: 0-18, 19-40, 41-60, and 61-92, and five categories by components. In order to determine the change of stone characteristics with respect to time, data were also divided into two periods, 2003-2007 and 2008-2012. A total of 12,846 stones were included in this study. The age of the patients ranged from 1 to 92 years with 7,736 males and 5,110 females. Stone made of single component was rare, 2.61%. Calcium oxalate stone was the most common component at 82.56%. Calcium oxalate and uric acid stones were more common in male than in female. The incidence of calcium phosphate stones and uric acid stones had increased during the past 5 years, while calcium oxalate stones decreased. We found the highest incidence of stone disease in the 41-60 years old group and the lowest in the 1-18 years old for both genders. Calcium oxalate was the dominant component in every group but was more prevalent in 19-40 years group. The percentage of magnesium ammonium phosphate stone and uric acid stone increased with age.