CT-defined body composition is associated with postoperative burst abdomen in patients undergoing laparotomy

Postoperative abdominal wall dehiscence (AWD) or burst abdomen (BA) is a relevant complication after abdominal surgery that causes additional surgical procedures, prolonged hospital stays and long-term morbidity. Several underlying risk factors exist and have been described in literature and consist of surgical and medical factors. Recently, CT-derived body composition is of rising interest to provide new prognostic factors in surgical patients. The present study aims to explore the association between CT-defined body composition and postoperative BA.

A database of patients who underwent abdominal surgery and developed post-operative wound infections in our institution between 2015 and 2018, was assembled. The subgroup of patients with BA was compared to a control group without BA. CT-defined body composition was evaluated in L3-level measuring skeletal muscle index (SMI) for sarcopenia assessment, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Clinical risk factors and CT-defined body composition were used to predict the occurrence of postoperative BA using discriminatory and binary logistic regression analyses.

A total of 118 patients, 92 (78%) with BA and 26 (22%) without BA were included in the analysis. CT derived body composition parameters for visceral obesity and sarcopenia showed statistically significant differences between the two cohorts. Patients with burst abdomen showed higher VAT (157.6 cm² vs. 84.9 cm², p = 0.001) and a significantly lower SMI (46.9 cm²/m² vs. 53.8 cm²/m², p = 0.016). Consequently, visceral obesity and sarcopenia were significantly more frequent in patients with BA (p = 0.02 and 0.01, respectively). In the multivariable Firth's penalized logistic regression, visceral obesity (OR = 4.87, 95% CI 1.32-21.91 p = 0.02), sarcopenia (OR = 5.94, 95% CI 1.65-26.68 p = 0.006), intestinal resection (OR = 9.33, 95% CI 2.33-55.65 p < 0.001) and length of the surgical wound (OR = 1.12, 95% CI 1.04-1.22 p = 0.001) were independently associated with the occurrence of burst abdomen.

CT-defined body composition with sarcopenia and visceral obesity are strongly associated with postoperative BA. This analysis should be further acknowledged as a potentially important risk factor in surgical care and could aid in clinical decision making.