Intraperitoneal insufflation of carbon dioxide rescues intestinal damage in an experimental murine model of colitis

Objectives: Necrotizing enterocolitis (NEC) is a severe neonatal surgical condition, associated with a prolonged pro-inflammatory state, leading to high mortality and morbidity rates. Carbon dioxide (CO2) insufflation during laparoscopy may have an anti-inflammatory effect. We aimed to evaluate the effects of CO2-insufflation on experimental colitis. Methods: Acute colitis was induced in 6-week-old Balb/c mice by the administration of 2%-dextran sulfate-sodium (DSS) during 7 days (n = 45). On Day 4, two groups received intraperitoneal insufflation (duration: 30 mn, pressure: 5 mmHg) of CO2 ("DSS+CO2") or air ("DSS+air"). A group received no insufflation ("DSS"). Groups were compared for clinical severity using the disease activity index (DAI-body weight loss, stool consistency, and bleeding), histological severity (histopathological activity index, colon length, and ulcerations), colonic mucosecretion, and inflammation. Results: DAI was significantly decreased in DSS+CO2 group, compared to DSS (p < 0.0001) or DSS+air (p < 0.0001) groups. Colon length was increased in DSS+CO2 treated mice compared to DSS (p = 0.0002). The histopathological activity index was lower in DSS+CO2 (vs. DSS, p = 0.0059/vs. DSS+air, p = 0.0389), with decreased ulcerations (3.77 vs. 10.7, p = 0.0306), and persistent mucosecretion with increased mucin-secreting cells. Conclusions: CO2-insufflation attenuates DSS-induced colitis and improves both clinical and histological scores. Laparoscopy with CO2 insufflation represents a therapeutic anti-inflammatory strategy for NEC.