OBJECTIVETo observe the anatomy structure of rabbit ear and the effect of different operation methods and post-operative treatments on the formation of hypertrophic scar.

METHODSThe experimental animals were 25 New Zealand white rabbits. 6 pieces of full skin specimens were obtained from each of the ears in 5 rabbits for histological examination. 6 full-thickness skin wounds (d = 8 mm) were made on different sites of ventral side of each ear in the other 20 rabbits. The total number of the wounds was 240. 120 wounds in 10 rabbits were divided into 4 groups randomly to receive different treatments on day 7 postoperatively. No treatment was performed in the other 120 wounds. The wounds healing and the scar formation were observed for six months. The scars were harvested 4 weeks and 8 weeks after operation for pathologic examination and measurement of scar elevation index (SEI).

RESULTSHistological analysis showed that the anatomy structure was different in different sites of the rabbit ear. The best sites for creating hypertrophic scar model were on the medial margin of the middle- and inferior part of ear. The depth of the wound should reach the cartilage membrane of the ear to facilitate the formation of hypertrophic scar. The second strip crust on day 7 postoperatively enhanced the wounds healing and minimized the scar proliferation and hypertrophy.

CONCLUSIONSThere is a close correlation between the anatomy structure of the ear and the creation of hypertrophic scar animal model. The wound site, the depth of wound and the post-operative treatment will affect the formation of hypertrophic scar. The study can help to improve the successful rate of creating hypertrophic scar animal model.