Stone Characteristics and Surgical Treatment Patterns Among Patients With Urolithiasis at a Brazilian Referral Hospital: A Retrospective Observational Study

Background: Urolithiasis is a common and recurrent disorder that can cause obstruction, infection, renal impairment, repeated emergency care, and the need for surgical intervention.Real-world treatment patterns may help referral centers understand case mix and plan endourological resources.Objective: To characterize the institutional surgical case mix of patients undergoing operative treatment for urolithiasis at a Brazilian nonprofit teaching hospital.Secondary exploratory analyses assessed the associations of stone location and stone size with the primary surgical procedure performed.Methods: This retrospective observational study included 624 unique patients aged 16 years or older who underwent rigid ureteroscopy, flexible ureterorenoscopy, or percutaneous nephrolithotomy between June 1 and December 31, 2025.Demographic, stone-related, operative, anesthetic, and ureteral stent variables were extracted from institutional records.Three secondary exploratory contingency analyses evaluated procedure versus stone location, procedure versus stone size, and stone location versus stone size using Pearson's chisquare tests; Cramer's V quantified effect size.Analyses involving missing stone size or location used complete cases.Results: Men accounted for 361 patients (57.9%), and mean age was 46.6 ± 13.8 years.Flexible ureterorenoscopy was the most frequent primary procedure (436; 69.9%), followed by rigid ureteroscopy (147; 23.6%) and percutaneous nephrolithotomy (41; 6.6%).Spinal anesthesia, alone or with sedation, was used in 559 patients (89.6%), and a double-J stent was used in 448 (71.8%).Procedure distribution varied markedly according to stone location (χ 2 (4) = 1108.77,p < 0.001; Cramer's V = 0.946; n = 619) and stone size (χ 2 (6) = 301.23,p < 0.001; Cramer's V = 0.505; n = 591).Stone size and location were also associated (χ 2 (6) = 323.63,p < 0.001; Cramer's V = 0.525; n = 588).Conclusions: Surgical care was dominated by minimally invasive endourological procedures.Procedure distribution varied markedly according to stone location and size.These findings describe the operative case mix of a Brazilian referral hospital and may support service planning and future prospective quality studies.