Experimental study of the young rabbit's ear cartilage autograft in expanded flap

Objective: To explore the effect of the expanded flap on the grafts of autogenous ear cartilage.Methods: Ten New Zealand white rabbits were involved and the right back skin flaps(experimental group) were expanded with 15 ml tissue expanders while the left sides(control group) weren't,after four weeks expansion we put two 1 cm×1 cm cartilages from the middle place of the same side ear(one was for measure,the other was for observation) into the expanded skin flaps and the same to the counterpart of the right side.The cartilages were observed for histologic and morphologic examination weekly,and measured 8 weeks later.Results: The cartilage showed 76.27% increase in surface area in the experimental group,while 52.95% increase in the control group(P<0.01).Microscopic observation:in experimental group the activity of cartilage was impaired in the first two weeks.From 3rd to 6th week the activity of cartilage was gradually enhanced and reached to its peak at the sixth week,subsequently the cartilage's activity weakened gradually but still higher than pre-transplantation.In control group degeneration was observed in the first week,and the morphology was close to pre-transplantation a week later.From the 2nd to 5th week the cartilage growth trend was similar to the experimental group but the peak was the 5th week.Conclusions: The autogenous cartilage of young rabbits had grown well in expanded flap.The growth trend of cartilage was a curve:first descend then ascend and last descend.