Single-Dose Versus Prolonged or no Antibiotic Prophylaxis for Surgical Site Infection after Adult Appendectomy: A Systematic Review

Background: Surgical site infection (SSI) remains a common complication following appendectomy. Although preoperative antibiotic prophylaxis is routinely recommended, it remains unclear whether continuing antibiotics postoperatively reduces SSI beyond a single preoperative dose, or whether prophylaxis can be omitted in low-risk patients, particularly in uncomplicated (non-perforated) appendicitis, where postoperative antibiotics serve no therapeutic role. This systematic review compared these strategies for preventing SSI in adults undergoing appendectomy. Methods: A systematic search of PubMed, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar was performed for studies published between January 2015 and December 2025. Studies involving adult patients undergoing open or laparoscopic appendectomy that evaluated preoperative antibiotic prophylaxis and reported SSI outcomes were eligible for inclusion. Randomized controlled trials and observational studies were included, whereas pediatric studies, case reports, editorials, conference abstracts, and studies evaluating antibiotics solely for therapeutic purposes were excluded. The review followed PRISMA 2020 guidelines. Risk of bias was assessed using RoB 2 for randomized trials, ROBINS-I for non-randomized studies, and the Newcastle–Ottawa Scale for cohort studies. Owing to heterogeneity in antibiotic regimens, comparators, and study designs, findings were synthesized narratively. The protocol was not registered. Results: Thirteen studies met the inclusion criteria. Given clinical and methodological heterogeneity, no meta-analysis was performed. Ten studies compared single-dose preoperative prophylaxis with prolonged postoperative antibiotic regimens, while three evaluated prophylaxis versus no prophylaxis in selected patient populations. Across studies, extending antibiotics into the postoperative period did not result in a consistent reduction in SSI compared with a single preoperative dose, irrespective of operative approach. Several studies reported increased healthcare costs, longer hospital stay, or greater antibiotic exposure with prolonged regimens. In the three studies evaluating omission of prophylaxis, all in highly selected populations, SSI rates did not differ significantly with or without prophylaxis; however, event numbers were small and the findings are not generalizable. Conclusions: In adults with uncomplicated or non-perforated appendicitis, limited evidence of variable quality suggests that a single preoperative dose may be adequate, as postoperative continuation did not consistently reduce SSI and may increase unnecessary antibiotic use. These findings should not be extrapolated to complicated appendicitis, and evidence supporting omission of prophylaxis is restricted to highly selected low-risk patients.