An Experimental Study Of The Influence On Costal Cartilage Reparative Regeneration By Replanting The Small Blocks Of Autogeneic Cartilage

Background Autogeneic costal cartilage was used in the operation of plastics constantly.The operation will influence the development of thoracic cage and cause thoracic deformity in the donor site especially when more costal cartilages were harvested.Some scholars replant the small blocks of autogeneic cartilage into the perichondrial pocket at the donor-site as well as reserve perichondrium and costochondral junction left completely intact in order to decrease incidence rate of thoracic deformity,but there is still no experimental evidence support this practice.Objective To build up an animal model of thoracic cage injuries caused by harvesting abundant costal cartilages and investigate the influence of costal cartilage reparative regeneration by replanting the small blocks of autogeneic cartilage into the perichondrial pocket at the donor-site .Methods Sixteen rarebits (8-10 weeks old, 1.8-2.2kg) were randomly divided into four groups. The 1.5cm in length of costal cartilage defect was made with the perichondrium and costochondral junction left completely intact. The cartilage defect was cloesd by 3 methods including suturation directly, replanting the small blocks of autogeneic cartilage and plugging bioprotein jelly after cartilage replanting. Each experimental group was handled with two methods in two sides of costal cartilage except control group which was breeded with other rarebits in the same condition without any other treatment. All the rarebits were sacrificed in 16 weeks postoperatively. Appearance of thoracic cage and prosthetic tissue were examined macroscopically. Haematoxylin-eosin staining was performed to evaluate the characteristics of prosthetic tissues and biomechanical detection was used to Measure intension of prosthetic tissues. Results The dissection of thoracic cage of rarebit was similar to the human, we can reserve perichondrium intactly and obtain costal cartilages with specified quantity and position easily, the postoperative administration is also convenient,so the rarebit is an ideal animal model of thoracic cage injuries caused by harvesting costal cartilages. All the sixteen rarebits were included in the final analysis. Macroscopic observation: the shape of thoracic cage appeared well without apparent deformities and had no obvious difference between experimental groups. Histological observation: the defect was filled with abundant fibrous tissue in each group. The chipping of cartilage can survive effectively with little proliferation. Biomechanical detection: the intension of prosthetic tissue in the non-replanted group[(193.92±41.41)N]was obviously less than the replanted group[(318.88±28.28)N], bioprotein jelly group[(301.00±39.52) N] and control group[(300.54±38.35) N]respectively (P<0.01). Furthermore, there was no statistical difference between other three groups (P>0.05).Conclusion 1. The rarebit is an ideal animal model of thoracic cage injuries caused by harvesting costal cartilages. 2.Although replanting the chipping of cartilage can't promote reparative regeneration of hyaline cartilage, it can definitively strengthen the intensity of prosthetic tissue, reinforce thoracic stability and decrease the incidence rate of postoperative chest wall deformity indirectly.