The Clinical Significance of Stone Culture in Endoscopic Upper Urinary Tract Stone Surgery: Its Association with Systemic Inflammatory Response Syndrome (SIRS) and Surgical Success.

OBJECTIVES: This study investigates the results of stone culture and the correlation with urine cultures, stone composition, postoperative systemic inflammatory response syndrome (SIRS) and surgical outcomes.

METHODS: This prospective study included 115 patients undergoing endoscopic retrograde lithotripsy. Urine culture at initial presentation, intraoperative urine cultures, and stone cultures were obtained from patients, and the variables were compared according to stone culture positivity.

RESULTS: Stone culture positivity was determined in 8.7% of patients. The most frequently isolated microorganism, at 50%, was Candida albicans. Hydronephrosis grade (p = 0.034), length of hospital stay (p = 0.003), urine culture positivity at initial presentation (p = 0.003), and intraoperative urine culture positivity (p < 0.001) differed significantly according to stone culture positivity. The incidence of SIRS was higher in these patients (p = 0.037), while the stone-free rate was lower (p = 0.021). The most common chemical stone type, at 66.9%, was calcium oxalate, and no significant correlation was observed between stone composition and stone culture positivity.

CONCLUSION: Stone culture positivity is associated with postoperative SIRS development and reduced surgical success. The study findings suggest that urinary stones may serve as a potential microbial reservoir, particularly in the presence of urinary obstruction, and that relying solely on urine culture at initial presentation may be insufficient for assessing postoperative infectious risk. Stone culture may be clinically valuable in terms of predicting postoperative risk and surgical success and of planning targeted antibiotic therapy particularly in patients with hydronephrosis.