镍钛形状记忆合金支架全耳郭再造:扫描电镜对置入后6及12个月周围组织结构变化的验证

背景:迄今已有很多材料代替自体软骨作为全耳郭再造的支架,各种材料均有利弊.虽然已有报道通过组织工程技术在裸鼠体内培育出具有人耳软骨复杂结构的软骨支架,将来可以使用在体外培育出的自体耳郭软骨作为全耳郭再造支架,但目前尚不能临床应用.目的:以镍钛记忆合金丝网作为耳郭再造支架,应用扫描电镜观察支架置入大白兔体内后周围组织的超微结构变化.设计、时间及地点:随机对照动物实验,于2005-04/2007-05在复旦大学附属眼耳鼻喉科医院中心实验室、复旦大学上海医学院电镜室、安徽省立医院病理科完成.材料:12只新西兰大白兔按随机数字表法分成扩张组和未扩张组,每组6只.方法:扩张组先行置入皮肤软组织扩张器皮下,扩张后再置入已制成人耳郭形状的镍钛合金丝网作为全耳郭再造的支架;未扩张组则直接皮下置入支架.主要观察指标:采用扫描电镜观察支架置入后6,12个月支架周围组织超微结构的变化情况.结果:镍钛形状记忆合金支架置入后增生的纤维组织穿透支架两侧形成完整包膜,组织内未见金属腐蚀和金属颗粒脱落等异常改变现象,裸露的镍钛形状记忆合金丝表面光滑,周围的纤维组织增生正常,细胞结构无异常改变,两组之间无明显差别.结论:镍钛形状记忆合金支架置入皮下可以顺利完成纤维血管化过程,周围组织结构未发生明显变化,支架的组织相容性较好.

Total auricular reconstruction using nitinol shape memory alloy stent: Scanning electron microscope verification of surrounding tissue structure changes at 6 and 12 months after implantation

BACKGROUND: Plenty of materials have been used as stent in total auricular reconstruction with varying advantages and disadvantages. The in vitro prepared tissue engineered complex cartilage stent has been not applied in clinic.OBJECTIVE: To observe the ultrastructure changes of surrounding tissues following total auricular reconstruction with nickel-titanium (NiTi) shape memory alloy stent in vivo.DESIGN, TIME AND SETTING: The randomized, controlled, animal experiment was performed in the Central Laboratory of EENT Hospital of Fudan University, Anhui Provincial Hospital and Department of Nuclear Medicine, Huashan Hospital of Fudan University from April 2004 to October 2005.MATERIALS: A total of 12 New Zealand rabbits were randomized divided into the skin-expanded and unexpanded groups, with 6 animals in each group.METHODS: Each animal underwent subcutaneous implantation with a NiTi alloy stent like human auricle. In the skin-expanded group, the stent was implanted after skin expansion, while no treatment in the unexpanded group.MAIN OUTCOME MEASURES: The ultrastructure changes of surrounding tissues were detected by scanning electron microscope at months 6 and 12 after implantation.RESULTS: Structure of nickel-titanium alloy implant stent make fibrovascular ingrowth more easily. The surface of nickel-titanium alloy stent was smooth without corrosion. There was no evidence of infection in the host tissue. Microstructure of Ni-Ti stent wires showed no morphologic and functional changes after subcutaneously implanted in vivo, and the difference between 2 groups had no significance.CONCLUSION: NiTi shape memory alloy stent can smoothly pass the process of fibrovascularization with less complication.According to the examination by SEM, the nickel-titanium stent showed good biocompatibility.