Clinical Outcomes of Antimicrobial Therapy for Postoperative Abdominopelvic Abscesses Not Amenable to Percutaneous Drainage

BACKGROUND: Postoperative abdominopelvic abscesses are primarily managed with antimicrobial therapy and percutaneous drainage. A subset of abscesses is unamenable to drainage due to small size or technical inaccessibility and is therefore managed conservatively with antimicrobial therapy alone. Clinical outcomes and factors of treatment failure with antimicrobial therapy alone for postoperative non-drainable abscesses remain poorly defined. METHODS: A retrospective cohort study included adult surgical patients at a tertiary hospital with abdominopelvic abscesses diagnosed within 30 days postoperatively and deemed non-drainable. All patients received systemic antimicrobials and were followed for 60 days. The primary outcome was therapy success. Other outcomes included clinical response, rehospitalization, and exploration of risk factors for antimicrobial therapy failure. RESULTS: The study included 69 patients. Abscesses were considered non-drainable because of inaccessible location (n = 47, 68.1%) or small size (n = 22, 31.9%). The median duration of antimicrobial therapy was 18 days, including 12 days of inpatient treatment. At 60 days from antimicrobials initiation, 53 patients (76.8%) achieved therapy success. The median time to clinical response was 8 days. Among patients with follow-up imaging, most demonstrated abscess resolution or reduction in size. Independent predictors of treatment failure were pelvic abscess location (odds ratio [OR], 6.8; 95% confidence interval [CI], 1.5-30.3) and postoperative corticosteroid exposure (OR, 11.9; 95% CI: 1.1-129.7). A longer interval between procedure and abscess diagnosis was inversely associated with failure (OR, 0.8 per day; 95% CI, 0.7-0.9). CONCLUSION: When postoperative abdominopelvic abscesses are deemed not amenable to drainage, antimicrobial therapy with close clinical follow-up was associated with favorable outcomes.