Postoperative Antibiotics After Appendectomy for Acute Appendicitis: No Evidence of Benefit, Even with Intra-Abdominal Fluid

Abstract

Objective: To evaluate the necessity of postoperative antibiotics following appendectomy for acute appendicitis, particularly in patients with intra-abdominal fluid, and to identify factors associated with postoperative infections.

Background: Postoperative antibiotic use after appendectomy remains controversial, especially in the presence of intra-abdominal fluid. While some surgeons prescribe antibiotics empirically, there is no consensus on whether they reduce the risk of postoperative infections in patients with intra-abdominal fluid accumulation.

Methods: A retrospective study was conducted at Saint Antoine Hospital (2013-2020) analyzing 1,539 patients with acute appendicitis (abscess and peritonitis were excluded). The presence of intra-abdominal fluid, antibiotic use, and postoperative outcomes were recorded. Risk factors for infections were identified through univariate and multivariate analysis.

Results: Intra-abdominal fluid was present in 880 patients(57.2%), with 474 exhibiting sero-sanguinous intra-abdominal fluid and 406 presenting purulent intra-abdominal fluid. Postoperative antibiotics were administered to 18.1% of patients, yet no significant difference in infection rates was found between patients with and without peritoneal intra-abdominal fluid . The study identified three independent risk factors for postoperative infection: ASA score (HR=5.129,P=0.004), symptom duration>2 days (HR=2.290,P=0.029), and the presence of appendicolith (HR=2.204,P=0.042). Postoperative antibiotic use did not significantly prevent infections, but inadequate antibiotic therapy was associated with higher rates of readmission and infectious outcomes.

Conclusion: Routine use of postoperative antibiotics for acute appendicitis, even with intra-abdominal fluid may not be necessary. Further research is needed to determine whether a targeted antibiotic approach based on risk factors for postoperative infections can improve outcomes without exacerbating antibiotic resistance.