How does pre-operative antimicrobial treatment influence the intra-operative culture results and infectious complications in patients with positive baseline bladder urine culture undergoing ureteroscopic lithotripsy?

We investigated how pre-operative antimicrobial treatment influenced intra-operative culture (IC) results and infectious complications in patients with positive pre-operative bladder urine culture (PBUC) undergoing ureteroscopic lithotripsy. We assessed 162 patients undergoing ureteroscopic lithotripsy from April 2019 to March 2020. Based on PBUC findings, they were divided into positive and negative PBUC groups. We administered pre-operative antimicrobial treatment to the positive PBUC group and only peri-operative antimicrobial prophylaxis to the negative PBUC group. We examined intra-operative cultures (ICs), including bladder urine culture, renal pelvic urine culture and stone culture, in all cases. We studied the association between the results of PBUC, ICs and infectious complications in both groups. A total of 67 and 95 patients had positive and negative PBUC, respectively. In the positive PBUC group, 19 (28.4%) patients still had positive bladder urine culture after the antibiotic treatment. Positive ICs (43.3% vs. 3.2%, p < 0.001) and post-operative fever (16.4% vs. 2.0%, p = 0.001) were more common in the positive PBUC group than in the negative PBUC group. In the positive PBUC group, 11 patients had a post-operative fever, regardless of the ICs results (6 positive ICs and 5 negative ICs). Furthermore, antimicrobial-resistant bacteria were detected from ICs in 5 patients with positive PBUC, including 4 suffering from a post-operative fever. Although the effect of pre-operative antimicrobial treatment is not definitive, to avoid serious infectious complications, we should recognize high-risk patients and perform more careful infection control based on the pre- and intra-operative culture results.