Novel Irradiated Axial Rotational Flap Model in the Rodent

Abstract Objectives: To design an easily reproducible rodent rotational skin flap and to evaluate the effects of radiation on flap viability. Methods: Ten rats received 40 Gy irradiation to the abdominal wall. Following a recovery period of one month, a 3 X 8 cm fasciocutaneous flap based axially on the inferior epigastric vessel, was raised and rotated 60 degrees into a contralateral deficit. Five non-irradiated rats underwent the identical procedure as a control. Animals were sacrificed seven days postoperatively, areas of flap necrosis were documented, and histological specimens were taken to compare flap viability and vessel density. Results: 60% of the rats in the irradiated group had necrosis of the distal flap ranging from 1 to 6 cm from the distal edge, whereas none of the animals (0%) in the control group exhibited necrosis (p\u3c0.001). Histology revealed collagen and vascular changes in the irradiated skin. Vascular density analysis revealed a significant difference between radiated and non-radiated flaps; p = 0.004, 0.029 and 0.014 in the distal, middle and proximal segments of the flap respectively. Conclusion: This novel rat axial rotational flap model demonstrates increases flap necrosis and a decrease in vascular density due to the effects of radiation. Using a linear electron accelerator a dose of 40 gy can be delivered to the skin without resulting in devastating gastrointestinal side effects