Experimental And Clinical Study Of Thin Costal Cartilage Used As Lateral Crural Onlay Graft In Correction Of The Cleft Lip Nasal Deformity

Objective:Feasibility of thin costal cartilage with perichondrium and its application in correction of cleft lip nasal deformity as lateral crural onlay graft.Materials and Methods:First,Rib cartilage in vitro experiment: 1.In vitro experiment of Pig Costal Cartilage: Fresh rib cartilages were divided into perichondrium and non-perichondrium groups,and both groups had different thickness and scratch,The cartilaginous slices,which were carved into 20 mm long and 5mm wide,were standardised within the first hour at 5 min intervals and at 2h and 3h respectively.By using Auto CAD software to analyze the image of cartilage,the curvature radius of different cartilage slices is calculated.By analyzing the data,we get the best cartilage specification for the lateral crural onlay graft.2.In Vitro experiment of Human Costal Cartilage: According to the experimental results of pig rib cartilage,the flexion of the human cartilage of the same size was selected to be in accordance with the experiment in vitro.Second,In Vivo experiment of Porcine Costal cartilage: The cartilage slices suitable for thickness and scratch in vitro were compared with the non-scratched group.The samples were divided into two groups: the Scratch Group(A1-A6)and the non-scratch Group(B1-B6),the sculpture was placed for 20 minutes for standardized photography.After the cartilage were implanted into the pig’s ear,the cartilage was taken out for photographing and the data were analyzed statistically.Third,Clinical study on the cartilage support of the large wing with thin rib cartilage: from September 2015 to September 2017,32 patients with cleft lip nasal deformity were treated use thin castal cartilage with perichondrium,13 cases were on the left side,14 cases were on the right side and 5 cases were bilaterally..18 Male,14 female,Median age was 24 years(18-33 years)and the median follow-up time was 8 months(6-20 months).Results:First,In Vitro experiment of Costal Cartilage: 1.The thinner the cartilage,the greater the warping.The relationship between scratch and flexural degree: scratch at 1.0 mm interval> cratch at 2.0 mm interval> without scratch.There was no statistical difference in the degree of warping in 20 minutes 2.The curvature radius of human costal cartilage of the same size is similar to that of pig cartilage.Second,2.In the experiment of pig transplantation,the curvature radius of A and B groups were increased by 4.12% and 4.19% in one month compared with those before implantation;In group A and B,the curvature radius were increased by 4.40% and 4.52%,respectively.There was no significant difference between 1 month and 3 month(P=0.983).Third,Clinical application: The postoperative incision healed in I period.The size and shape of the alar of the patients were stable,without exposure,Hematoma,infection and so on.The highest point of the patient’s nostril to the x-ray distance was(4.65±1.74)mm before operation,(10.26±2.82)mm after operation,and(18.46±2.51)mm before operation and(14.10±2.47)mm after operation,there were significant differences before and after operation(t=-8.423,P<0.001;t=4.973,P<0.001).There was no change of shape in the rib cartilage donor area.Conclusions:In vitro experiments showed that the costal cartilage with perichondrium,1.0 mm thickness,1 mm scratch interval were close to the Lower lateral cartilages,and had sufficient supporting strength.20 min as the standard for the stability time of external bending in this experiment.The results of in vivo test showed that there was a difference between before implantation and one month after implantation,but the extent of the difference was within the permissible range.There was no significant difference between one month and three month after implantation(P=0.983),which meant that the clinic was reliable.The thin costal cartilage with perichondrium was carved in the same way as the lateral support graft,which was applied to cleft lip nasal deformity,it can be used as one of the ideal materials for the cartilage transplantation of the alar cartilage in the cleft lip nasal deformity.