OBJECTIVETo establish an animal model of hypertrophic scar on the rabbit ears and to observe the dynamic process of scar formation on the ventral side of the rabbit ears.

METHODSFull skin defect (2 cm x 5 cm in diameter) was created on the ventral side of 60 ears in 32 New Zealand white rabbits. 1% silver sulfadiazine cream was applied to the wounds, and the dressing was changed once a week till wound healing. Four ears without operation were taken as control. Wound healing under natural condition was observed continuously for 12 months after the operation. The scar proliferation on the rabbit ears was observed by light microscope and transmission electron microscope, and the scar index was determined by computer image analyzing system.

RESULTSThe color, thickness and texture of the wounds on the rabbit ears after epithelization underwent a process of scar overgrowth, maturation and degeneration. The change in scar index was in accordance with the wax and wane of scar proliferation.

CONCLUSIONThe hypertrophic scar formed on the ventral side of rabbit ears after natural healing of full thickness skin wounds was similar to that in humans. The results indicated that this animal model was ideal for the study of the developmental mechanism of hypertrophic scars and for the evaluation of the efficacy of the prevention and treatment of hypertrophic scars.