The effect of ideal urine culture time on urinary infections after flexible ureteroscopy: A match‐pair case‐control study

Abstract

Aims:To investigate the effect of the ideal period (Δ-day), which is a period between the sterile urine culture and initiation of flexible ureteroscopy (f-URS), on postoperative urinary tract infections (UTI) in our tertiary referral centre. Methods:After obtaining the approval of the local ethics committee, retrospective data were collected for all f-URS procedures performed between January 2017 and March 2019. Patients that developed UTI were matched in 1:1 proportion with patients that did not develop UTI based on their demographic and stone characteristics.The group of patients with postoperative UTI was compared with the control group.Results: A total of 916 f-URS cases that had all required data were analysed. Sixtyeight patients with postoperative UTI were determined and a total of 136 patients were included in the study after match-pair. We found that if the Δ-day is longer than 2 weeks, the possibility of postoperative urinary infection rates increases with statistical significance (P = .006). According to our subgroup analysis, postoperative UTI was more common if the Δ-day >14 days. ROC curve analysis provided a 14.5-day period as a cut-off value of Δ-day for postoperative UTI. Conclusions:The present study is the first to examine the impact of the Δ-day for f-URS on postoperative UTIs. In brief, prolonging the Δ-day, especially if Δ-day >14 days, leads to an increase in the rates of postoperative UTI. We conclude that it is preferred to either perform the f-URS in the early period after the urine culture analysis or doing the urine culture analysis shortly before the surgery.