Influence of Growth Factors Erythropoietin and Granulocyte Macrophage Colony Stimulating Factor on Mechanical Strength and Healing of Colonic Anastomoses in Rats
To find out what influence erythropoietin and granulocyte macrophage colony stimulating factor (GM-CSF) had on the healing of left colonic anastomoses in rats. Experimental study. University hospital of Ioannina, Greece. 40 rats. An end to end anastomosis was created in the left colon. The rats in the experimental groups were treated with erythropoietin, or GM-CSF, or the two in combination. Tensile breaking strength of the anastomosis, histological characteristics of the anastomosed segment, changes in body weight, and packed cell volume (PCV) during the experiment. The tensile breaking strength of the anastomosis on the seventh postoperative day was significantly greater in the erythropoietin group (mean 2.8N, 95% confidence interval (CI) 0.12N, p 0.0004) than in the control group (mean 1.60N, 95% CI 0.12N). It did not differ from the GM-CSF groups (mean 1.67N, 95% CI 0.21N, p 0.68) or erythropoietin GM-CSF (mean 1.67N, 95% CI 0.11N, p 0.44). The PCV was significantly higher in the two groups given erythropoietin (p < 0.001) but not in the GM-CSF group (p 0.8) while that in the control group was significantly lower (p < 0.001). The body weight followed the same pattern, being significantly more in the two groups given erythropoietin (p = 0.03 and 0.003) but not in controls (p = 0.09) or the GM-CSF group (p = 0.2). Erythropoietin enhances the healing of anastomosis in rat colon by increasing the number of fibroblasts and accelerating the maturation of new vessels.