Presentation Authors: Francesca Carobbio, Stefania Zamboni, Marco Lattarulo*, Damiano D'Aietti, Evelyn Van Hauwermeiren, Luca Cristinelli, Alessandro Antonelli, Claudio Simeone, Brescia, Italy
Introduction: UTI is a well-known complication after ureteral stent placement but the relationship between device colonization and infection is still not clear. Aim of our study is to assess predictors of bacterial colonization of stents and of postoperative infectious complications in patients who underwent ureteroscopy (URS) for stones in a single-center cohort.
Methods: We retrospectively evaluated data of patients with indwelling stent submitted to URS for renal or ureteral stones from January 2017 to July 2018. Antibiotic prophylaxis consisted of a single dose of Cefoxitin 2 g iv in patients with negative preoperative UC. Otherwise, the choice of antibiotic was based on antibiogram. Ureteral stent was removed before URS procedure and analyzed. No postoperative antibiotic was given. Multivariable logistic regression analysis (MVA) was built to assess pre-operative predictors of postoperative infectious complications.
Results: 88 consecutive patients with available SC and UC were included. Overall, 22 patients (25%) had positive UC and 37 (42%) positive SC. 19 patients (22%) developed infectious complications and fever remains the most common one, with 11 cases. All complications occurred between 2nd and 3th post-operative day. Majority of patients (93%) who developed a postoperative infection had a positive SC; in those with a positive SC, concordance between colonization of SC and UC was found in 71% of patients who developed an infectious complication. E. Faecalis, which is not responsive to common prophylaxis schemes usually based on a 2nd generation cephalosporin, was the most frequent pathogen isolated. At MVA preoperative UC positivity (Odds Ratio [OR]:11.13, 95% Confidence Interval [CI]:3.32-37.23, p < 0.001) was the only predictor of SC positivity. The only predictor of development of postoperative infectious complications was SC positivity (OR:11.00, CI:1.08-111.14, p=0.04).
Conclusions: E. Faecalis was the most frequent pathogen isolated, which is usually not responsive to common prophylaxis schemes which should be changed in an association between a penicillin and an aminoglycoside. Positive SC is the only independent risk factor for postoperative infection but about 30% of patients have discordance between SC and UC: as a consequence, UC may not be appropriate to assess prophylaxis scheme as well as SC which requires, at the moment, 2-5 days for being processed. An early cultural analysis could allow a prompt antibiotic therapy in all patients with positive SC even if mildly symptomatic.