Abstract
BACKGROUND: Surgical site infections (SSI) are associated with worse healthcare outcomes and increased costs. Recent evidence suggests dissimilar outcomes for SSI subtypes. Abdominal surgery has the largest SSI incidence compared to other surgeries. However, outcomes are often aggregated, masking potential impact differences. This systematic review is the first to separately summarise outcomes associated with incisional and organ/space SSI in abdominal surgery. MATERIALS AND METHODS: A systematic search of PubMed, Embase, and CINAHL was conducted for studies published between 1992 and 5th December 2024. Outcomes of interest were excess hospital length of stay (LOS), mortality risk, and proportions of readmitted and repeat surgery patients. Studies reporting at least one outcome for incisional or organ/space SSI in abdominal surgeries for adults were included. Risk of bias was assessed using the Newcastle Ottawa Scale and the Cochrane Risk of Bias tool for observational studies and randomized controlled trials respectively. RESULTS: Twenty studies were included, pooling 23,567 patients. Five reported outcomes for incisional, one for organ/space and 14 studies for both SSI subtypes. Patients with incisional SSI had an average excess LOS of 5.02 days (3.04-7.01), while organ/space SSI patients had a longer excess LOS of 14.40 days (10.11-18.69). Incisional SSI were associated with weakly increased mortality risk (1.62, 0.74-2.50), while organ/space SSI had increased mortality risk (2.75, 2.56-3.54). Proportions of readmissions were 16% (5-27%) for incisional and 37% (5-69%) for organ/space SSI. Proportions of patients who undergo repeat surgery were 4% (0- 9%) for incisional and 9% (4-14%) for organ/space SSI. CONCLUSION: This study revealed a significant burden of SSI, particularly organ/space SSI, which are associated with worse overall outcomes. Infection prevention and control strategies to reduce the impact and cost of SSI might be improved, with a need for targeted efforts against organ/space SSI.