Unintended consequences of antibiotic practices: the relationship between bowel preparation, prolonged prophylaxis, and ileus after radical cystectomy.

Postoperative ileus (POI) after radical cystectomy (RC) is a common complication that carries significant morbidity. Prolonged antibiotic usage has been associated with an elevated risk of POI. The American Urological Association guidelines recommend that only a single dose of peri-procedural antibiotic prophylaxis is sufficient. This study aims to evaluate the association between oral antibiotic bowel preparation (ABP) and prolonged surgical antibiotic prophylaxis (SAP) (>24 h) with postoperative ileus (POI) following radical cystectomy (RC). A retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program procedure-targeted RC dataset was performed. Patients with clinical indications for extended antibiotic use were excluded. POI was defined as nil per os status, or nasogastric tube use beyond postoperative day three, or reinstitution of either on or after day four. Clinical, perioperative and oncological characteristics were compared between patients to identify factors associated with POI. Among 5098 patients undergoing RC, the incidence of POI was 12.4%. A small fraction of patients received ABP (6.5%), mechanical bowel preparation (MBP) was given to 22.1% of patients, and 23.4% patients received SAP for more than 24 h. On univariate analysis, ABP (Odds ratio (OR) 1.711), open surgical approach (OR 1.542), prior pelvic radiotherapy (OR 1.515), age > 65 years (OR 1.386), SAP > 24 h (OR 1.378), and receipt of chemotherapy within 90 days (OR 1.220) were associated with POI. However, on multivariate analysis, only oral ABP (OR 1.692, p = 0.009), SAP > 24 h (OR 1.460, p = 0.04), and age > 65 years (OR 1.361, p = 0.031) remained independently significant. Oral ABP and prolonged SAP are associated with increased risk of POI following RC. These findings underscore the importance of adherence to evidence-based perioperative protocols and antibiotic stewardship to improve postoperative outcomes in urologic oncology.