Colloid vs. crystalloid infusions in gastrointestinal surgery and their different impact on the healing of intestinal anastomoses

The aim of this study was to investigate if colloid infusions have different effects on intestinal anastomotic healing when compared to crystalloid infusions depending on the amount of the administered volume. Twenty-eight Wistar rats were randomly assigned to four groups receiving different amounts of either a crystalloid (Cry) or a colloid (Col) infusion solution. Animals with volume restriction (Cry (-) or Col (-)) were treated with a low and animals with volume overcharge (Cry (+) or Col (+)) with a high flow rate. All animals received an infusion for a 60-min period, while an end-to-end small bowel anastomosis was performed. At reoperation, the anastomotic bursting pressure (millimeters of mercury) was measured, as well as anastomotic hydroxyproline concentration. The presence of bowel wall edema was assessed histologically. Median bursting pressures were comparable in the Col (-) [118 mm Hg (range 113-170)], the Cry (-) [118 mm Hg (78-139)], and the Col (+) [97 mm Hg (65-152)] group. A significantly lower median bursting pressure was found in animals with crystalloid volume overload Cry (+) [73 mm Hg (60-101)]. Corresponding results were found for hydroxyproline concentration. Histology revealed submucosal edema in Cry (+) animals. In case of a fixed, high-volume load, colloids seem to have benefits on intestinal anastomotic healing when compared to crystalloid infusions.