The effects of locally injected granulocyte macrophage-colony stimulating factor on the healing of intraoperatively irradiated intestinal anastomoses in rats

Abstract

Intraoperative irradiation is used to reduce the number of local recurrences and to increase disease free survival in the treatment of intestinal malignancies. Irradiation for the local control of tumours diminishes the wound healing in the intestine as in any other tissues. For many surgeons, it seems too risky to make resection and anastomosis in an irradiated intestine. Granulocyte Macrophage-Colony Stimulating Factor (Gm-csf) had been successfully used in chronic and incisional dermal wounds. In this study, we evaluated the effect of locally applied Gm-csf on intraoperatively irradiated rat small intestinal anastomosis. 160 male Sprague-Dawley rats were randomized into 4 groups. In group 1 (control), ileal resection was made (1 cm. in length) and anastomosis was performed. In group 2, ileal resection and anastomosis were performed and 50 microgr. rHu Gm-csf was injected subserosally in the perianastomotic area. In group 3, intraoperatively 2000 cGy irradiation was applied to the intestine following ileal resection and anastomosis. In group 4, ileal resection and anastomosis were performed, and 50 microgr. rHu Gm-csf was injected subserosally in the perianastomotic area, then intraoperatively 2000 cGy irradiation was applied to the intestine. On the 3rd and 7th days, relaparotomies were made in order to measure the bursting pressures of the anastomotic segments. The measurement of hydroxyproline levels were evaluated to determine the amount of anastomotic collagen. Histopathological evaluations were also performed. The bursting pressure values in gm-csf given groups were significantly higher than their control groups. The hydroxyproline content of group 4 was significantly higher than group 3 on the 3rd day. In conclusion, these data indicate that local injection of Gm-csf improves the wound healing of intraoperatively irradiated bowel anastomosis.