Abdominal subcutaneous obesity and the risk of burst abdomen: a matched case–control study

Purpose: The causes of burst abdomen after midline laparotomy remain uncertain. Obesity is a suspected risk factor. The purpose of this study was to investigate the association between abdominal subcutaneous obesity (ASO) and burst abdomen in patients undergoing emergency midline laparotomy. Methods: We conducted a single-centre, retrospective, matched case–control study of patients undergoing emergency midline laparotomy from May 2016 to August 2021. Patients suffering from burst abdomen were matched 1:4 with controls based on age and sex. Abdominal wall closure was standardized in the study period with the small bites, small stitches technique. ASO was defined as the highest sex-specific quartile (≥ 75%) of subcutaneous fat layer evaluated on CT. The primary outcome was the association between ASO and burst abdomen, stratified between cases and controls. Secondary outcomes included 30- and 90-day mortality, length of stay, and suspected risk factors of burst abdomen, assessed by multivariate analysis across cases and controls. Results: A total of 475 patients were included in this study, with 95 cases matched to 380 controls. Liver cirrhosis, active smoking, and high alcohol consumption were more common among cases in an unadjusted analysis. Liver cirrhosis (odds ratio (OR) 3.32, p = 0.045) and active smoking (OR 1.98, p = 0.009) remained significant in a multivariate analysis and were associated with burst abdomen. One hundred twenty-four patients had ASO. ASO was not significantly associated with burst abdomen (OR 1.11, p = 0.731). Conclusion: ASO was not found to be associated with an increased risk of burst abdomen after emergency midline laparotomy.