Protective effects of rectal ozone administration on colon anastomoses following radiotherapy.

BACKGROUND: Anastomotic leakage (AL) following rectal surgery is associated with increased mortality and morbidity. Neoadjuvant radiotherapy disrupts the wound healing process in rectal surgery. OBJECTIVES: To evaluate the effects of intra-rectal ozone application on rectal anastomoses after radiotherapy. MATERIAL AND METHODS: This study was performed on animals. Thirty-two male Wistar rats were randomly divided into 4 groups: control group, ozone group, radiotherapy group, and radiotherapy/ozone group. Ozone was administered intrarectally in the ozone group and water was administered intrarectally in rthe control group for 5 days. The radiotherapy group received 20 Gy of pelvic radiotherapy. The radiotherapy/ozone group received 20 Gy of pelvic radiotherapy after the administration of ozone. Afterward, colon resection followed by an anastomosis were performed under general anesthesia in all groups. Anastomotic segments were resected to evaluate tissue hydroxyproline (HYP) and myeloperoxidase (MPO) levels, perform a histological evaluation, and measure bursting pressure. RESULTS: There were no statistically significant differences between groups regarding tissue MPO levels (p = 0.55). Tissue HYP levels were significantly decreased in the radiotherapy group (p = 0.04). Bursting pressure was found to be significantly lower in the radiotherapy group (p < 0.05). No significant differences were found between adhesion scores in the control and ozone groups. Exudate formation was significantly lower in the radiotherapy group (p < 0.05). The lowest macrophage scores were found in the radiotherapy group (p < 0.05). Fibroblast scores were the highest in the control group and the lowest in the radiotherapy group (p < 0.05). CONCLUSIONS: Intra-rectal ozone application significantly improved the anastomotic healing process after radiation exposure.