Establishment and evaluation of an improved rat model of open abdomen

Introduction:This study aimed to establish an animal model of open abdomen(OA)through temporary abdominal closure via different techniques.Methods:Adult male Sprague-Dawley rats were randomly divided into three groups:group A(OA with polypropylene mesh alone);group B(OA with polypro-pylene mesh combined with a patch);and group C(OA with polypropylene mesh and a sutured patch).Vital signs,pathophysiological changes,and survival rates were closely monitored in the rats for 7 days after surgery.Abdominal X-rays and histopathological examinations were performed to assess abdominal organ changes and wound healing.Results:The results showed no significant difference in mortality rates among the three groups(p>0.05).However,rats in group B exhibited superior overall condi-tion,cleaner wounds,and a higher rate of wound healing compared to the other groups(p<0.05).Abdominal X-rays indicated that varying degrees of distal intestinal obstruction in all groups.Histopathological examinations revealed fibrous hyperpla-sia,inflammatory cell infiltration,neovascularization,and collagen deposition in all groups.Group B demonstrated enhanced granulation tissue generation,neovasculari-zation,and collagen deposition compared to the other groups(p<0.05).Conclusions:Polypropylene mesh combined with patches is the most suitable method for establishing an animal model of OA.This model successfully replicated the patho-logical and physiological changes in postoperative patients with OA,specifically the progress of abdominal skin wound healing.It provides a practical and reliable animal model for OA research.