Operative procedures in warm humidified air: Can it reduce adhesion formation? A randomized experimental rat model

•Exposure of peritoneum to warm and humidified air during open surgery.•Exposure of peritoneum led to increased postoperative adhesion formation.•Increased adhesion formation possibly due to increased bacterial load observed.

BackgroundPostoperative peritoneal adhesions form in 63–97% of patients, give rise to subsequent adhesion related problems and create a considerable socioeconomic burden. In the present study, a local artificial atmosphere was created around the abdominal cavity during a surgical procedure in an effort to reduce postoperative adhesion formation.MethodsForty-eight Wistar male rats (Clr:WI) were randomized into two groups and weighed about 280 grams each. The abdominal cavities of the rats of the study group were exposed to warm and humidified air (21% O2, 37 °C, 95–100% relative humidity (RH)) during an open surgical procedure, while the rats of the control group were exposed to the air from the operating theatre (21% O2, 21 °C, 40–47% RH). The surgical procedure consisted of a midline laparotomy, four cuts and ischaemic knots in the anterior abdominal wall and blood from the tail vein dripped into the abdominal cavity. The abdominal cavity was assessed for adhesion formation and the bacterial load (CFU/ml) was measured.ResultsSignificant differences in mean total adhesion, severity, tenacity scores and in the mean rank of the extent scores were found (p<0.001p<0.001). Also, significant differences in the median numbers of CFU/ml on chocolate agar and blood agar were found (p<0.001p<0.001).ConclusionsRats in the study group had higher total adhesion, extent, severity and tenacity scores postoperatively compared to rats in the control group. A possible reason could be the observed higher bacterial load amongst the rats of the study group compared to the rats of the control group.