Preoperative irradiation and colonic healing.

Objective: To find out if preoperative irradiation of 10 + 10 Gy influences anastomotic healing in the lower left colon of the rat.

Design: Randomised study.

Material: 120 male Wistar rats.

Interventions: Rats were randomised to be given localised preoperative irradiation or sham treatment 8 and 4 days before a standardised left colon resection. The post-operative course was studied for up to two months.

Main Outcome Measures: Changes in body weight, white cell count, haemoglobin and albumin concentrations, anastomotic complications, anastomotic breaking strength, hydroxyproline content and myeloperoxidase activity in the anastomotic segment.

Results: General effects of irradiation were seen as delayed increase in body weight and low white cell count. Anastomotic complications were not increased. Anastomotic breaking strength was similar in the early postoperative phase but reduced after 2 months. Hydroxyproline content and myeloperoxidase activity of the anastomotic segments were similar in irradiation and control animals.

Conclusion: Anastomotic healing was not compromised by preoperative irradiation. Late effects may be present in the bowel wall but further investigation is required.