COMPOSITE GRAFT-SURVIVAL - AN AURICULAR AMPUTATION MODEL

Objective: To study the effects of corticosteroids and fibroblast grow th factor on composite graft survival using a rabbit model of auricula r amputation and reimplantation. Design: Randomized, ''blinded,'' plac ebo-controlled, prospective animal study.Setting: Animal laboratory in tertiary care center. Intervention: Amputation of the distal 2 cm of the rabbit ear as a composite graft and reimplantation with simple 6-0 prolene sutures. All animals underwent the same surgical procedure an d were randomized into the following four groups: (1) surgical reimpla ntation alone; (2) 30 mg/kg intramuscular methylprednisolone sodium su ccinate for 5 days, starting immediately postoperatively; (3) topical basic fibroblast growth factor for 5 days postoperatively; and (4) del ayed reimplantation with corticosteroids. In group 4, the ears of the animal were amputated, placed in iced saline containers for 90 minutes , and given 30 mg/kg intramuscular methylprednisolone for 5 days, with the first dose starting immediately prior to reimplantation. Main Out come Measures: Percentage graft survival and histologic characteristic s of viable and nonviable composite graft tissue. Results: The groups that received corticosteroids and delayed reimplantation with corticos teroids had a statistically significant increase in percentage of graf t survival compared with the control group (P<.003 and P<.006, respect ively). The growth factor group showed no significant difference from the control group. Conclusion: Neovascularization occurred in the viab le grafts, thus suggesting its role in graft survival. This study esta blishes the efficacy of corticosteroids in enhancing composite graft s urvival.