Effects of unfractionated heparin and low-molecular-weight heparin on colonic anastomoses in the presence of experimental peritonitis.

摘要

BACKGROUND: We aimed at investigating the effects of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) on the healing process of colonic anastomoses in the presence of peritonitis which is known to adversely affect the healing process. STUDY DESIGN: Three groups of Wistar albino rats (n = 15 in each group) with experimental fecal peritonitis were studied. A 1-cm colonic segment was resected, and an end-to-end anastomosis was performed. The control group (group 1) was given no treatment; group 2 animals received 50 IU/kg s.c. UFH twice a day, and group 3 rats received LMWH at a dose of 1.5 mg/kg daily for 7 days postoperatively. Relaparotomy was done on day 7 in the surviving rats. The rats were sacrificed by resection of the colonic segment. The anastomosis bursting pressures were measured and the tissue samples from anastomosis lines were histopathologically examined. RESULTS: The bursting pressures were significantly higher in UFH and LMWH groups as compared with the controls (p = 0.021 and p < 0.001, respectively), while there was no statistically significant difference between UFH and LMWH groups. Positive bacterial culture results were more common in controls (90%) than in the other two groups (p = 0.029 and p = 0.002, respectively). Also the polymorphonuclear leukocyte counts were higher (p = 0.005) and the fibrin formation more common (p = 0.007) in the controls. On the other hand, the number of fibroblasts was higher (p = 0.002) and collagen formation and revascularization more frequent (p = 0.001 and p = 0.001, respectively) in the UFH and LMWH groups. CONCLUSION: UFH and LMWH may have positive effects on the healing process of colonic anastomoses in the presence of peritonitis.