Infective complications after retrograde intrarenal surgery: a new standardized classification system.

PURPOSE: Retrograde intrarenal surgery (RIRS) is considered a safe procedure; however, infective complications are potentially serious postoperative complications. The aim of this multicentre study was to evaluate prospectively the prevalence of infective complications after RIRS and identify risk factors. METHODS: Baseline data were collected, and patients were questioned regarding postoperative infective complications following RIRS. The Fisher exact test, Student t test, Mann-Whitney U test, and multivariate regression analysis were used for data analysis. RESULTS: A total of 403 patients from five European centers were included. Antibiotic prophylaxis was administered prior to RIRS in 100 %. Infection complications were recorded in 31 patients (7.7 %), consisting of fever in 18 (4.4 %), SIRS in 7 (1.7), and sepsis in 3 (0.7 %). Three required hospitalization for non-obstructive pyelonephritis (0.7 %). Univariate analysis revealed that coronary heart disease, chronic kidney disease, alteration of lipid metabolism, anticoagulant therapy, past surgery for renal stone, presence of residual fragments were predictors of infective complications. Multivariate analysis did not identify any patient subgroups at a significantly higher risk of infection. The low rate of complications may have limited the conclusions from our study. CONCLUSION: Using a standardized method for the definition and classification of infective complication from a multicentre prospective large database, we find a prevalence of 7.7 % of infective complication among patients undergoing RIRS for renal stone. However, to predict which patients will develop infective complications still remains a clinical challenge.