Effect of nutritional route on colonic anastomotic healing in the rat

Although early enteral feeding has been shown to benefit cutaneous healing when compared to parenteral feeding, the effect of the route of nutritional support in gastrointestinal anastomotic healing has not been defined. The aim of the present study was to determine whether the route of nutritional support influences colonic anastomotic healing. Twenty male Sprague-Dawley rats weighing 270 to 290 grams underwent identical surgical manipulation consisting of central venous catheterization, gastrostomy insertion, and distal colonic anastomosis (single-layer, inverted). Identical nutrient infusates composed of 4.25% amino acids, 25% dextrose, and vitamins were administered, with half the animals receiving the infusions via the gastrostomy and the other half via the venous catheter. Animals were killed 5 days after surgery. There were no differences in nutritional parameters between the parenterally and enterally fed groups. Colonic anastomotic bursting pressure was significantly higher in the enterally fed group (180 +/- 6 vs. 150 +/- 11 mm Hg; P <0.01). The measured insoluble collagen and total protein content in anastomotic tissue were enhanced in the enterally supported group. The fraction of soluble (newly synthesized) collagen did not differ between the two groups. The data demonstrate that the route of nutrient administration influences colonic anastomotic healing. The preservation of colonic structural collagen in the enteral group may improve the ability of the gut to hold sutures and thus enhance anastomotic healing.