扩张器辅助制作多孔硅橡胶耳支架进行耳廓成形术的实验研究

Auricle reconstruction assisted by an expander using porous silicon auricle frame

目的探讨扩张器辅助下制作多孔硅橡胶耳廓成形术支架的可行性。方法应用螺旋CT对1只耳廓中等大小、形态正常的成年男性的头颅进行连续薄层容积扫描，应用Mimics8．1、Geomagicstudio12软件提取耳廓前表面数据，并设计1．4mm厚度的耳支架的三维模型及相对应的金属模具，用医用高分子硅橡胶制成1．4mm厚度的硅橡胶耳支架，用打孔器在硅橡胶耳支架间隔1mm打出直径1mm的孔洞。分别在10只新西兰大白兔背部中线一侧的肉膜与深筋膜之间置入50m1肾形扩张器，注水至160ml后，维持扩张1个月。然后取出扩张器，分别放入厚1．4mm的多孔硅橡胶耳支架，术后观察再造耳廓是否变形、挛缩、外露，共6个月。结果再造耳廓有弹性、可压缩，外观无明显变形、挛缩、外露，耳舟、三角窝、耳轮、对耳轮等耳廓亚单位清晰可辨。结论应用计算机辅助建模设计的1．4mm厚硅橡胶支架可对抗扩张皮瓣的收缩，经进一步实验观察，待条件成熟后，可征招志愿者考虑试用于临床扩张器辅助的耳廓成形术。

Objective To investigate the possibility of auricle reconstruction assisted by an ex- pander using porous silicon auricle frame. Methods An adult male with average sized, normal ears was selected. The spiral CT scan was used to acquire primitive data of his external ear. Mimics 8. 1 and Geomagic studio 12 were used for 3D reconstruction and image processing. Three-dimensional model of auricle 1.4 mm in thickness was created according to the anterior auricular surface data. Fi- nally, a metal model was made according to the 3D model of auricle. By the extrusion method, silicon auricle frame was formed from the metal model. Multiple perforations, 1 mm in diameter and 1 mm in- ternal from each other, were then made by a puncher. 50 ml kidney tissue expanders were implanted between the panniculus carnosus and the fascia through an incision on the backs of 10 New Zealand white rabbits. The expander was inflated with 20 ml saline weekly, to a total of 160 ml. Maintenance of expansion lasted for a month. The expander was then removed through an incision along the ex- pander near the back. Silicon auricle frame was inserted into the pocket. The reconstructed ears were observed for 6 months postoperation. Whether there were deformations, contractures and extrusions were observed. Results The reconstructed ears were elastic and compressible. No deformation, con- tracture or extrusion were observed 6 months postoperation. Scaphoid fossa, triangular fossa, helix, antihelix were legible. Conclusions The silicon frame, 1.4 mm in thickness manufacted by computer aided design, could stand up to contraction of the overlying expanded flap, and it thus is possible to be used for auricle reconstruction assisted by the expander.