Mortality in patients with secondary peritonitis treated by primary closure or vacuum-assisted closure: nationwide register-based cohort study.

BACKGROUND: Secondary peritonitis caused by gastrointestinal perforation is associated with significant morbidity and mortality. Effective management includes surgical source control, antibiotic therapy, and intensive resuscitation. The choice between primary abdominal closure (PAC) and vacuum-assisted closure (VAC) in the management of secondary peritonitis remains a subject of debate. METHODS: This Danish nationwide register-based cohort study included patients undergoing emergency surgery for secondary peritonitis from perforation of the small intestine, colon, or rectum between 2007 and 2021 who were treated with either PAC or VAC. Data were extracted from national registries, including the Danish Register of Cause of Death and the Danish National Patient Registry. The primary outcome was overall all-cause mortality; secondary outcomes were all-cause mortality at 30 days, 90 days, and 1 year. RESULTS: In all, 13 898 patients were included (1017 in the VAC group, 12 881 in the PAC group). VAC-treated patients had significantly higher Charlson Co-morbidity Index scores and were slightly younger. In the subgroup with available laboratory data, VAC-treated patients also presented with more severe biochemical derangements, including elevated C-reactive protein, leukocytes, bilirubin, and lactate, as well as lower haemoglobin, suggesting a higher baseline severity of illness. The overall risk-stratified mortality rate (RSMR) was 49.1% for VAC and 52.0% for PAC (P = 0.222). The 30-day mortality rate was 16.9% in both the VAC and PAC groups, with RSMR of 17.4% and 18.3%, respectively (P = 0.656). At 90 days, mortality was 24.3% and 22.5% in the VAC and PAC groups, respectively, with a corresponding RSMR of 23.2% and 24.2% (P = 0.437). One year after surgery, the mortality rate was 31.3% for VAC and 29.5% for PAC, with a corresponding RSMR of 30.3% and 31.6% (P = 0.346). CONCLUSION: This nationwide cohort study revealed no significant differences in mortality between PAC and VAC in patients with secondary peritonitis at any of the designated time points. Demographic and laboratory data suggest that VAC-treated patients had a higher baseline severity of illness.