Open Abdomen and Fluid Instillation in the Septic Abdomen: Results from the IROA Study.

Background: Open abdomen (OA) is a surgical option that can be used in patients with severe peritonitis. Few evidences exist to recommend the use of intraperitoneal fluid instillation associated with OA in managing septic abdomen.

Methods: A prospective analysis of adult patients enrolled in the International Register of Open Abdomen (trial registration: NCT02382770) was performed.

Results: A total of 387 patients were enrolled in two groups: 84 with peritoneal fluid instillation (FI) and 303 without (NFI). The groups were homogeneous for baseline characteristics. Overall complications were 92.9% in FI and 86.3% in NFI (p = 0.106). Complications during OA were 72.6% in FI and 59.9% in NFI (p = 0.034). Complications after definitive closure were 70.8% in FI and 61.1% in NFI (p = 0.133). Entero-atmospheric fistula was 13.1% in FI and 12% in NFI (p = 0.828). Fascial closure was 78.6% in FI and 63.7% in NFI (p = 0.02). Analysis of FI in negative pressure wound therapy (NPWT) showed: Overall morbidity in NPWT was 94% and in non-NPWT 91.2% (p = 0.622) and morbidity during OA was 68% and 79.4% (p = 0.25), respectively. Definitive fascial closure in NPWT was 87.8% and 96.8% in non-NPWT (p = 0.173). Overall mortality was 40% in NPWT and 29.4% in non-NPWT (p = 0.32) and morality during OA period was 18% and 8.8% (p = 0.238), respectively.

Conclusions: We found intraperitoneal fluid instillation during open abdomen in peritonitic patients to increase the complication rate during the open abdomen period, with no impact on mortality, entero-atmospheric fistula rate and opening time. Fascial closure rate is increased by instillation. Fluid instillation is feasible even when associated with nonnegative pressure temporary abdominal closure techniques.