Duodenum Clamping Trauma Induces Significant Postoperative Intraperitoneal Adhesions on a Rat Model

OBJECTIVE: The purpose of this study was to investigate the histological and morphological changes in the first two postoperative weeks on a rat intraperitoneal adhesion model induced by duodenum clamping trauma. METHOD: The rat model of postoperative intraperitoneal adhesions was established in 48 male Wistar rats by laparotomy, followed by the duodenum clamping trauma. Rats were sacrificed respectively on 1(st), 3(rd), 5(th), 7(th) and 14(th) day after the operation. The control rats were sacrificed immediately after the operation (0 day). Then the intraperitoneal adhesions were assessed macroscopically. Histopathology and immunohistochemistry were performed to evaluate the fibrosis, inflammatory responses, neovascularization, and cells infiltration in adhesion tissues. In addition, the changes of the mesothelium covering the surgical sites were examined by scanning electron microscopy. RESULTS: Our study revealed that duodenum clamping trauma induced by mosquito hemostat can result in significant postoperative intraperitoneal adhesions formation. The extent and tenacity of intraperitoneal adhesions reached their peaks on 3(rd) and 5(th) days, respectively. Histopathological examination showed that all rats developed inflammatory responses at the clamped sites of duodenum, which was most prominent on 1(st) day; the scores of fibrosis and vascular proliferation increased slowly from 3(rd) to 5(th) day. Myofibroblasts proliferated significantly in the adhesion tissues from 3(rd) day, which were examined by immunohistochemical method. And the mesothelium covering the surgical sites and the adhesion tissues healed on 7(th) day. CONCLUSION: This study suggests that clamping trauma to the duodenum can result in significant postoperative intraperitoneal adhesions formation, which represents an ideal rat model for intraperitoneal adhesions research and prevention. And myofibroblasts may play an important role in the forming process of intraperitoneal adhesions.