The Clinical Application Of 3-Dimensional Rib Cartilage Computed Tomography On Adult Auricle Reconstruction

PurposeTo study the clinical value of three-dimensional CT about rib cartilage on auricle reconstruction of adult congenital microtia with autogenous rib cartilage, including providing the basis for the preoperative evaluation and surgical design, assisting in harvesting rib cartilage and assisting in carving three-dimensional ear scaffold.Clinical Materials and Methods1. Research Objects Between January 2014 and December 2014,46 adult patients with congenital microtia had been through auricle reconstruction surgery in auricular reconstruction center Ⅱ of Plastic Surgery Hospital, CAMS. Among 46 patients (34 male,12 female),16 cases were on left side,27 cases were on right side,3 cases were bilateral. Age ranged 18 to 41 years old.2. Research Methods2.1 Machine parameters and methods of measurement Using 64 layer spiral CT for high-resolution scan of rib cartilage. Scanning parameters: the spacing 0.6 mm,120KV, rotation time 0.75r/sec and reconstruction volume lmm. After scanning, all of the original cross-sectional images were used to get thin layer reconstruction. Then the reconstructed images were imported into workstation to generate a three-dimensional reconstruction image of rib cartilage. Import Original of extremitas sternalis. The content of intraoperative measurement included the number, length, width of costochondral junction, width of rib end and width of extremitas sternalis. Rib cartilage would be scored by the rib cartilage criteria during carving ear scaffold.2.3 Statistical AnalysisUse statistical analysis software SPSS17.0 for windows to carry out T test between two groups, and Variance analysis between multiple groups. If the test results P<0.05, then the difference is of statistical significance.Results1. There were 20 cases (43.48%) with bilateral asymmetry of the sixth, seventh, eighth rib cartilage. Meanwhile, there were 14 patients (30.43%) with significantly calcified rib cartilages. There was 1 case (2.17%) with rib cartilage fracture during harvesting rib cartilage. There were 2 cases (4.35%) with mild chest deformity.2. Comparing length of the 7th rib cartilage of left and right side, the 6th,7th rib cartilage’s costochondral junction width and extremitas sternalis width of both sides, the test result P<0.05, then the difference is of statistical significance. The difference of the 6th rib cartilage’s CT value between both sides is of statistical significance. The difference of the 7th rib cartilage’s CT value between both sides is of statistical significance. But there was no statistically significant difference between both 8th rib cartilages’ CT value.3. The difference is of statistical significance between the preoperative and intraoperative measurement data, length of the 6th,7th rib cartilage. But there was no statistically significant difference between between other the preoperative measurement data and intraoperative one.4. There was no statistically significant difference among those groups divided by age. The difference of rib cartilage CT value between genders was of statistical significance. Rib cartilage CT values of female patients were larger than male patients.5. CT values and scores of rib cartilages were negatively correlated. There was no statistically significant difference among the 6th,7th rib cartilage’s CT value. There was no statistically significant difference among the 6th,7th rib cartilage’s scores.ConclusionPreoperative three-dimensional CT reconstruction of bilateral rib cartilage can accurately show the rib size, shape, curvature, direction and calcification. There are distinct advantages about this technique, such as preoperative assessment of rib cartilage and surgical method design, precisely guiding the surgery of rib cartilage taken and giving assistance on caving ear scaffold. Three-dimensional CT measurement can provide reliable evidence of preoperative evaluation for adult patients with microtia malformation. Meanwhile, it can reduce the blindness of auricle reconstruction rib cartilages taken and improve the stability of fine ear scaffold. Rib cartilage 3D CT reconstruction technique should be promoted in the clinical treatment of ear reconstruction.