Effects of methylene blue, pentoxyphylline and enoxaparin on postoperative adhesion formation and markers of angiogenesis in a rat uterine horn model

Postoperative adhesions still remain as a common and serious problem leading to morbidity, mortality and economic loss. Adhesions are the major cause of postoperative intestinal obstruction, infertility, and chronic pelvic pain. In this study, we aimed to compare adhesion prevention effects of pentoxyphylline, enoxaparin and methylene blue and to investigate the effects of these agents on angiogenesis, which is suggested as an important step in wound healing, in rat a uterine horn model. Forty female Wistar albino rats were randomized into four subgroups and underwent laparotomy. Adhesions developed following cauterization at the anti-mesenteric surfaces of both uterine horns. After 14 days, adhesions were investigated by using macroscopic, histopathological and immunohistochemical [vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor (TGF-beta), platelet-derived growth factor (PDGF)] methods. We found that enoxaparin significantly reduced adhesion formation. Pentoxyphylline had no significant effect on adhesion formation, whereas methylene blue had a significant decreasing effect on histopathologically determined adhesion markers and it may affect angiogenesis through PDGF. Among three agents, which were intraperitoneally given by a single dose manner in order to prevent postoperative adhesions, methylene blue and enoxaparin exhibited a positive effect, while no such effect was shown with pentoxyphylline.