Composite graft survival. An auricular amputation model.

OBJECTIVE

To study the effects of corticosteroids and fibroblast growth factor on composite graft survival using a rabbit model of auricular amputation and reimplantation.

DESIGN

Randomized, "blinded," placebo-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 and were randomized into the following four groups: (1) surgical reimplantation alone; (2) 30 mg/kg intramuscular methylprednisolone sodium succinate for 5 days, starting immediately postoperatively; (3) topical basic fibroblast growth factor for 5 days postoperatively; and (4) delayed 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 OUTCOME MEASURES

Percentage graft survival and histologic characteristics of viable and nonviable composite graft tissue.

RESULTS

The groups that received corticosteroids and delayed reimplantation with corticosteroids had a statistically significant increase in percentage of graft survival compared with the control group (P < .003 and P < .006, respectively). The growth factor group showed no significant difference from the control group.

CONCLUSION

Neovascularization occurred in the viable grafts, thus suggesting its role in graft survival. This study establishes the efficacy of corticosteroids in enhancing composite graft survival.