Effects of enoxaparin on the healing of abdominal wall in rats: study on breaking strength and histopatology

Abstract

PURPOSE: To evaluate the influence of enoxaparin on the abdominal wall healing. METHODS: Sixty Wistar male rats were randomly distributed into two experimental groups. Group E: consisted of 30 rats, submitted to abdominal suture and treated with enoxaparin in a dose of 1 mg/kg of body weight, subcutaneously administered from immediate postoperative until the 7th day; Group C: consisted of 30 rats submitted to abdominal suture and treated with the equivalent dose per volume of NaCl 0.9%. The animals were submitted to median laparotomy and were operated again at the 3rd, 7th or 14th postoperative day for the resection of the anterior abdominal wall. The tissue's stretching resistance was tested and a histopathological evaluation was performed. Through Mann-Whitney's U test, a statistical analysis was conducted considering significant values for p <0.05. RESULTS: The tensile breaking strength presented a median of 0.64N for group C and 0.41N for group E (p=0.60) at the 3rd postoperative day; of 2.27N for group C and of 4.32N for group E (p=0.01) at the 7th POD; of 5.72N for group C and of 6.62N for group E (p=0.97) at the 14th POD. In relation to the histopathological study, the results did not show significant statistical differences, except for the amount of collagen at the 7th POD, which medians were 2 on group C and 1 on group E (p=0.007). CONCLUSION: Considering the conditions in which this study was conducted, the administration of enoxaparin led to an strengthening of the tissue's breaking resistance at the 7th POD; on the histopathological exam, a significant difference was observed at the 7th POD, with a better collagen disposition on group C.