Duration of post‐operative antibiotic treatment in acute complicated appendicitis: systematic review and meta‐analysis

Background Appendicitis is the most frequent aetiology of acute abdominal pain requiring surgical treatment, with an estimated lifetime risk between 7% and 8%. Antibiotics play a substantial role in treatment, and there is considerable debate regarding the duration of antibiotics in treating appendicitis. Methods We searched multiple databases from inception until June 2019 for peer‐reviewed studies that compared different durations of antibiotic treatment after appendicectomy for acute complicated appendicitis in adults. We dichotomized reported data into short‐ and extended‐term antibiotic use and controlled for different definitional thresholds in the meta‐analysis. We generated risk ratios using restricted maximum likelihood methods and mixed effects modelling for each outcome of interest. Results Four observational studies involving 847 participants were included in the meta‐analysis. For the primary outcomes of intra‐abdominal infection, we did not find a statistically significant difference between extended‐ and short‐term antibiotic strategies for intra‐abdominal infection (Risk ratio 0.92, 95% confidence interval (CI) 0.49–1.74). Three randomized controlled trials involving 291 participants were included in a separate meta‐analysis. We found that extended antibiotic usage was not associated with a statistically significant reduced risk for intra‐abdominal infection (RR 0.52, 95% CI 0.21–1.29) or surgical site skin infection (RR 1.44, 95% CI 0.43–4.81). Conclusion This systematic review and meta‐analysis found that extended post‐operative antibiotic treatment may not be associated with a reduced risk of intra‐abdominal infection; however, meta‐analysis was significantly limited by heterogeneity between studies and underpowered trials. Further large randomized controlled trials are needed to confirm these findings. A systematic review and meta‐analysis of pooled data from existing literature was performed, demonstrating extended post‐operative antibiotic treatment following appendicectomy in acute complicated appendicitis is not associated with a reduced risk of intra‐abdominal infection.