Trial and error: a mapping review of operative and perioperative strategies to reduce post-appendicectomy abdominal infection

INTRODUCTION: Post-appendicectomy abdominal infection (PAAI) is a frequent event, both in clinical practice and in research studies. There is a need to reduce PAAI to improve outcomes and avoid antibiotic resistance. We systematically mapped published evidence evaluating the delivery of components of appendicectomy hypothesised to influence PAAI. METHODS: Systematic searches of MEDLINE, Embase and Cochrane Central were performed from 2005 to 2025, to identify published and ongoing randomised controlled trials (RCTs) registered in trials databases, and systematic reviews of RCTs, where PAAI was reported as an outcome. Abstracts and full texts were screened independently. Data extraction included study populations, inclusion/exclusion criteria, interventions/comparators and outcomes. Appendicectomy was deconstructed into component parts and identified interventions were grouped and reported accordingly. RESULTS: From 613 abstracts, 97 studies were included: 13 systematic reviews, 53 RCTs and 31 registered RCTs. Thirty studies were adult-only, 31 child-only and 35 had mixed populations. Exclusion criteria frequently included pregnancy, immunosuppression, diabetes, sepsis and prior antibiotic use. PAAI was the primary outcome in 22 of 53 RCTs, usually defined by postoperative imaging. Interventions assessed for reduction of PAAI included laparoscopic surgery, method of stump closure, suction and irrigation, and perioperative antibiotics. Although results for intraoperative technical interventions were conflicting, a review of preoperative antibiotics showed significant benefit despite heterogeneity of regimens. CONCLUSION: Preoperative antibiotics reduce PAAI, although the optimal regimen is uncertain. Evidence for intraoperative techniques such as stump closure and contamination management is inconsistent and unclear, warranting assessment in a large, pragmatic, platform style RCT.