Preoperative urine culture - Is it necessary to prevent infectious complications following ureterorenoscopy?

To prevent postoperative infectious complications, a urinary tract infection should be either diagnostically excluded or treated prior to ureterorenoscopy (URS). URS is a frequently performed endoscopic surgery for urological stone removal. Although the urinary dipstick test represents a simple and cost-effective method to gain information about the presence of urinary tract infection, the prevailing procedure is the more expensive and more time-consuming method of urine culture. The aim of this retrospective single-center study was to compare two strategies of perioperative prophylaxes prior to URS and to evaluate their impact on postoperative infectious complications: I) Obtaining a urine culture in every patient prior to URS or II) only in case of a positive dipstick test. Therefore, we retrospectively compared 201 patients in two cohorts undergoing URS. In one cohort a urine culture was obtained only in case of a positive dipstick test of midstream urine sample and in the second cohort a urine culture was prepared for every patient regardless of the dipstick's test results. The study's end point was determined as "infectious failure" (IF), if more than one of the following criteria are fulfilled: postoperative fever, elevation of inflammation laboratory values, significant prolongation of hospital stay and readmission within short-notice. Simple and multiple logistic regressions were performed to evaluate the influence of patient characteristics and preoperative urine analysis strategy on the occurrence of IF. Patients with a score of the American Society of Anesthesiologists (ASA) > 2 had a nearly statistically higher risk (p = .09) to develop an IF than healthier patients with an ASA score ≤ 2. Prestenting was determined as a significant predictive factor (p = .04) for a postoperative IF. No difference in patients with or without IF was detected regarding the two preoperative urine analysis strategies. Sensitivity of dipstick test was 87.5% and the negative predictive value was 89.66%. We found that a negative urine dipstick test result obtained prior to URS eliminated the need for urine culturing in predicting postoperative infectious complication. This approach can reduce preoperative preparation-time and costs without affecting postoperative complication outcomes.