颌面部爆炸伤致耳蜗和耳蜗神经损伤的超微结构变化

背景颌面部高速投射伤对耳蜗损伤的研究已有报道,但爆炸伤对耳蜗超微结构的影响尚在研究中.目的探讨颌面部爆炸伤对耳蜗损伤的影响,电镜观察其超微结构改变.设计以实验动物为研究对象,随机对照、观察性研究.单位一所军医大学医院耳鼻咽喉科,口腔颌面外科实验室.材料实验于1995-08/1997-07完成.在第三军医大学新桥医院动物所建立颌面部爆炸伤致伤模型,口腔颌面外科实验室进行标本处理,第三军医大学电镜室进行电镜观察.杂种健康犬15只,雄雌不限,体质量9.5～13.5kg,平均11.3kg,随机分为3组.致伤1组=5只,致伤2组=5只,正常对照组=5只.方法选用8号工程纸壳火引爆雷管致伤10只犬颌面部,造成重型颌面伤,致伤1组、致伤2组分别于伤后1 h和6 h取伤侧耳蜗进行扫描电镜和透射电镜观察.对照组动物麻醉后不致伤,观察指标、标本处理与致伤组相同.结果致伤动物均有耳蜗和耳蜗神经明显超微结构变化,早期主要表现为毛细胞纤毛紊乱,耳蜗神经内结构水肿,线粒体变性,6 h后变性改变广泛存在,纤毛脱落、常见鞘内结构溶解.结论颌面部爆炸伤对耳蜗超微结构损伤严重,但早期仍多为可逆性损伤.

Ultrastructure changes of cochlea and cochlear nerve after maxillofacial blast wound

BACKGROUND: There have been reports about the cochlea injury after high-velocity projectile wounding. The effect on ultrastructure of cochlea after blast was still unclear.OBJECTIVE: To investigate ultrastructural changes of cochlea and cochlear nerve after maxillofacial blast wound.DESIGN:A randomized controlled observational trail with dogs as subjects.SETTING: Otolaryngeal Department and Maxillofacial Surgery Laboratory of the Third Military Medical University of Chinese PLA.MATERIALS: The study was conducted from August 1995 through July 1997. The animal model in maxillofacial blast wound was established in Animal Center of Xinqiao Hospital of the Third Military Medical University of Chinese PLA. Specimens were treated in Maxillofacial Laboratory and observed in Electron Microscope Laboratory. Totally 15 dogs of either sex (weighting 9. 5 - 13.5 kg, mean 11.3 kg ) were randomly divided into three groups with 5 in each group. Two groups served as trauma groups 1 and 2 and the other group as control.METHODS: The maxillary and mandibular regions of 10 dogs in trauma groups were wounded by model 8 cardboard-shelled detonators to establish animal model of maxillofacial blast wound. At the 1st and 6th hour after trauma the wounds were examined and specimens of cochlea and cochlear nerve were dissected out for electron microscopic observation to study the ultrastructural changes. The specimens in the control group were treated the same way as those in the trauma groups except for blast injury.RESULTS: After wounded, the cochlea and cochlear nerve in the early period manifested cilia disorder, edema of the nerve and mitochondrial degeneration. At the 6th hour after trauma there were extensive degeneration in cochlea and cochlear nerve, cilia fallen off hair cells and dissolution of the structures in nerve sheath.CONCLUSION: The ultrastructural changes of cochlea and cochlear nerve are severed as a result of maxillofacial blast wound, but in early period the injury is reversible. So it is very important that early cure should be emphasized in treatment.