Establishment of an Animal Model of Rabbit's Ear with Intermediate Stage Hypertrophic Scar

Objective To establish an animal model of intermediate stage hypertrophic scar on the rabbit ears and to find out the best sites of scar formation.Methods A total of 240 full-thickness skin and tissue defect directing access to the cartilage surface was created on the ventral side in 20 Japan white rabbits and each ear contain 6 defect sites.The wound was treated by exposure method.On the 7th day after operation,the granulation tissue and plasma shell were removed on the cartilage.Wound healing and scar proliferation under natural condition were observed continuously for 3 months.The scar formation and collagen distribution were observed by HE and Sirius red staining,and the collagen content was analyzed by using computer image analysis system.Results The ventral wound of rabbit's ears produced hypertrophic scar similar to human hypertrophic scar,the incidence of scar was between 42.5% to 56.7% .The peak of scar proliferation was in 30 days to 50 days after operation.The degree of scar proliferation and collagen content varied at different sites.Conclusion The ventral wound of rabbit's ears can produce intermediate stage hypertrophic scar model,the middle sites and the lateral ear tip are ideal site for madding animal model of hypertrophic scar on the rabbit ears.