Influence of arginine dietary supplementation on healing colonic anastomosis in the rat

INTRODUCTION: This study sought to determine whether dietary arginine influences colonic anastomotic healing in the rat model. METHODS: Three groups of 42 Sprague-Dawley rats were fed 0, 1, and 3 percent arginine diets for three preoperative and three postoperative days. Animals underwent transection of the transverse colon with handsewn anastomosis. Subgroups of 14 animals in each dietary group were killed on postoperative Days 6, 10, or 14, and bursting pressures, histologic inflammation, and collagen content were compared. RESULTS: Mean anastomotic bursting pressures on postoperative Day 6 were lower for the 0 percent arginine group than the 1 and 3 percent arginine groups (mean ± standard error of the mean = 134 ± 6 mmHg, 164 ± 7 mmHg, and 166 ± 7 mmHg, respectively; P < 0.0005). On Days 10 and 14, no significant differences in bursting pressures were noted between arginine diets. Mean bursting pressures on postoperative Day 6 (155 ± 4 mmHg) were significantly lower than on Days 10 (204 ± 5 mmHg) and 14 (217 ± 6 mmHg; P < 0.001) for all arginine diets. Microscopic evaluation of the anastomoses did not show significant differences in inflammation or collagen content between arginine diets. Collagen content in all dietary groups peaked at Day 10. CONCLUSIONS: Perioperative arginine deficiency in the rat model is associated with impaired anastomotic healing during the first week, as reflected by lower bursting pressures. Arginine supplementation to 3 percent does not improve bursting pressures above those found in the usual 1 percent arginine diet at 6, 10, or 14 days. Bursting pressures plateau by Day 10 regardless of perioperative dietary arginine, whereas collagen content peaks at Day 10 after six-day perioperative arginine diet manipulation.