Effects of early pre- and postoperative irradiation on the healing of microvascular anastomoses

A comparative study was undertaken to evaluate the possible effects of time selection of irradiation on the healing of microvascular anastomoses. In t his experimental study, 40 adult male Sprague-Dawley rats were divided into four groups, 10 animals in each. In Group 1, the rats were exposed to radi otherapy with a dose of 20 Gy in a single fraction at a 170,916 cby/min dos e rate, at an 80-cm source to a skin distance from 3 to 4 cm in the right g roin Fields involving the femoral artery, using a Co60 megavoltage radiothe rapy machine. The animals were operated on under general anesthesia 2 weeks later. During the operation, Femoral microarterial anastomoses were perfor med. In Group 2, the rats were irradiated and operated on as in Group I, on the same day. In Group 3, the rats were operated on and, 2 weeks later, ir radiated, as in Group 1. In Group 4 (control group), the rats were operated on as in Group 1 No radiotherapy was performed. All rats were explored und er general anesthesia after 1 month. Patency was evaluated, and the anastom otic sites were taken for histopathologic and electron microscopy studies. The authors found that there were no major differences in the healing of mi crovascular anastomoses in the early preoperative, immediate preoperative, and early postoperative irradiated groups. The patency rates of all radioth erapy groups were not statistically different from control arteries (p < 0. 05).