Free flaps and irradiated recipient vessels: an experimental study in rabbits

In an experimental study in rabbits the effect of previous irradiation to the recipient vessels on the survival rate of free flaps was evaluated. Pre-operative radiotherapy was given in a single anterior neck field using a Cobalt60 unit, 1.25 MeV, SSD 80 cm in a fractionated dose corresponding to 5000 rad/5 weeks. An experimental model using paired data was established using two epigastric free flaps in each animal: one anastomosed to the irradiated vessels (carotid and jugular vein) and implanted outside the irradiated field and the other flap anastomosed to the normal femoral vessels and also implanted outside the irradiated field. In a sequential analysis it was found that free flaps anastomosed to irradiated recipient vessels within 12 weeks from the start of radiotherapy failed significantly more often than free flaps anastomosed to normal recipient vessels (p less than 0.10). This supports the view that preference should be given to the use of non-irradiated recipient vessels for microvascular transfer of free flaps.