Introduction
Infectious complications can often occur after surgery performed for the treatment of upper urinary tract stones. Preoperative bladder urine culture (PBUC) analysis has become a standard application before any stone surgery. Previous studies have shown that a positive PBUC indicates an increased possibility of postoperative infectious complication development [1].It is contraindicated to perform flexible ureterorenoscopy (f-URS) in the presence of a positive PBUC. However, infectious complications can occur even in the presence of prophylactic antibiotics and a negative PBUC [2]. It has been reported that although perioperative antimicrobial prophylaxis (PAP) is given after stone surgery, fever may develop in 4.4% and sepsis in 0.7% of patients [3]. In addition, infectious complications are among the most feared complications after f-URS. Despite the application of prophylactic antibiotherapy suitable for PBUC, infectious complications after f-URS cannot be completely prevented.
The results of the PBUC susceptibility test do not correlate well with the results of renal pelvic urine culture (RPUC) analysis [4]. It has been demonstrated that growth in RPUC is an important marker for infection development after endoscopic operations [5]. Despite antibiotic treatment or PAP, growth may occur in cultures taken intraoperatively, or postoperative urinary tract infection may develop depending on factors such as obstruction and antimicrobial resistance in the urinary system [6]. In addition, antibiotherapy applied as a result of obstruction in the upper urinary system that can cause hydronephrosis may lead to the incomplete destruction of bacteria and increase bacterial resistance due to its insufficient efficacy [7]. If there is a bacterial focus in the upper urinary system and if this can be predicted before the operation using any method, patients can be treated with a more appropriate antibiotic or appropriate prophylaxis before the intervention/operation. While the American Urological Association (AUA) guidelines suggest that PAP should be applied to all patients to reduce urosepsis after f-URS, the European Association of Urology (EAU) recommends that it should only be given to patients with a high risk of infection [8-10].However, PBUC may not fully reflect the microbiological state in cases of upper urinary tract obstruction [11]. Even if PBUC is negative, RPUC can be positive, especially in the presence of upper urinary tract obstruction. It has been shown that in patients undergoing percutaneous nephrolithotomy, RPUC and stone culture taken during surgery can provide additional information for treatment planning in those that develop an infection in the postoperative period [12,13]. However, the role of cultures taken during f-URS has not yet been fully revealed.
In this study, we evaluated the consistency between the results of PBUC taken preoperatively and RPUC taken at the beginning of the f-URS operation and to determine the predictability of a positive RPUC based on associated preoperative markers.