Effects of the amniotic membrane on healing of colonic anastomoses in experimental left-sided colonic obstruction

Abstract

We investigated the effects of the amniotic membrane on experimental primary colonic anastomoses of colonic obstruction in rats. Fifty female Sprague-Dawley rats were used in this study. All rats were submitted to a 2-0 silk ligature obstruction of the left colon 4 cm above the peritoneal reflexion and were reoperated upon 24 h later. Ten animals served as controls for measurement of bursting pressure, while the other 40 animals underwent colonic resection followed by primary anastomosis and were divided into two groups, the anastomosis (O) and amniotic membrane (OA). The latter group had anastomoses covered by amniotic membranes. Fifty percent of both OA and O groups were killed on postoperative day 3 (OA3, O3), and the other 50% were killed on postoperative day 7 (OA7, O7). Bursting pressures were significantly higher in groups OA3 and OA7 compared to those in O3 (p < 0.5) and O7 (p < 0.01), respectively. Inflammatory cell infiltration and adhesion scores were significantly lower in groups OA3 and OA7 compared to those in O3 (p = 0.001 and p < 0.01, respectively) and O7 (p = 0.001 and p < 0.05, respectively). Neoangiogenesis, fibroblast activity, collagen deposition, and hydroxyproline concentrations were significantly higher in groups with amniotic membrane than in groups without amniotic membrane (p < 0.05, for all comparisons). Covering colonic anastomoses with amniotic membranes has a positive effect on both the early and late phases of anastomotic healing on left-sided large bowel obstruction and provides a safer and stronger alternative than suturing one.