Open Abdomen in Obese Patients: Pay Attention! New Evidences from IROA, the International Register of Open Abdomen

Background: Open abdomen is the cornerstone of damage control strategies in acute care and trauma surgery. The role of BMI has not been well investigated. The aim of the study was to assess the role of BMI in determining outcomes after open abdomen. Methods: This is an analysis of patients recorded into the International Register of Open Abdomen; patients were classified in two groups according to BMI using a cutoff of 30 kg/m². The primary outcome was in-hospital mortality; secondary outcomes were primary fascia closure rate, length of treatment, complication rate, entero-atmospheric fistula rate and length of ICU stay. Results: A total of 591 patients were enrolled from 57 centers, and obese patients were 127 (21.5%). There was no difference in mortality between the two groups; complications developed during the open treatment were higher in obese patients (63.8% vs. 53.4%, p = 0.038) while post-closure complications rate was similar. Obese patients had a significantly longer duration of the open treatment (9.1 ± 11.5 days vs. 6.3 ± 7.5 days; p = 0,002) and lower primary fascia closure rate (75.5% vs. 89.5%; p < 0,001). No differences in fistula rate were found. There was a linear correlation between the duration of open abdomen and the BMI (Pearson’s linear correlation coefficient = 0,201; p < 0,001). Conclusions: Open abdomen in obese patients seems to be safe as in non-obese patients with similar mortality; however, in obese patients the length of open abdomen is significantly higher with higher complication rate, longer ICU length of stay and lower primary fascia closure rate. Trial registration number: ClinicalTrials.gov, Identifier: NCT02382770.