Epidemiology of urinary stone composition in the Southwest of France: a 23-year single-center retrospective study.

Introduction: Urolithiasis is a frequent disease whose prevalence is increasing worldwide. The epidemiological study of urinary stone composition allows to understand the lithogenic processes and makes it possible to improve individual management and orienting public health policies to prevent stone disease.

Material and methods: We retrospectively report a series of 6825 urinary stones collected in single university hospital of southwest France between 1999 and 2022. Stone composition was determined by infrared spectroscopy and data were analyzed according to period, age, sex and anatomical location.

Results: Our results indicated an average age of 49.5 years and a male/female sex ratio of 1.99 which tended to decrease over time. In adults, calcium oxalate is the predominant compound, and urolithiasis was preferentially located in the upper urinary tract. Uric acid is more common in bladder stones from men after 50 years. Calcium phosphates (especially carbapatite) and struvite were the main constituents of bladder stones from young women aged 20 to 30 years, pointing particularly to an infectious process. Drug-induced stones are uncommon, and essentially composed of anti-infective drugs. In children, urolithiasis predominated in the kidney and young boys aged 6 to 10 years were mostly affected with urinary stones formed mainly of carbapatite, whereas weddellite was the main compound identified in girls.

Conclusion: Our data highlight the composition of urinary stones according to age, gender and anatomic localization over a large two decades period. These results complete epidemiological data previously published in large-scale national studies in France and across the world.