Effects of external beam radiation on the allograft dermal implant

OBJECTIVE: The purpose of this study was to define the effects of external beam radiation (EBR) on AlloDerm (LifeCell Corp) through the analysis of gr aft thickness, fibroblast recellularization, and neovascularization as a fu nction of time. METHODS AND MATERIAL: Thirty-six male Sprague-Dawley rats (n = 36) were ran domly assigned to 1 of 4 groups (A, B, C, and D). AlloDerm was implanted su bcutaneously into the hind legs of each rat, and 20 Gy of EBR was administe red to one side. Grafts harvested 1, 2, 4, and 12 weeks after radiation wer e subjected to blinded histologic analysis. RESULTS: In groups A, B, and C, the irradiated grafts showed a significant decrease in recellularization versus nonirradiated (P < 0.001). At 12 weeks (group D), recellularization equalized, but neovascularization was signifi cantly less (P = 0.048) in the irradiated group. Graft thickness was unaffe cted. CONCLUSIONS: In the rat model, EBR of the implanted AlloDerm graft hinders recellularization in the early posttreatment period. However, EBR did not a dversely affect graft thickness, recellularization or ultimate graft surviv al.