Objective To discuss the formation mechanism of indirect injury of tympanic membrane and its specific clinical manifestations. Methods 20 cases of adult cats were randomly divided into two groups evenly:Gradually pressure group and constant pressure group. All aspects of the situation, such as the injury mechanism of tympanic membrane, the position, size, shape of perforation, condition of bleeding in laceration area,damage of external canal, etc. Results The location of ruptured tympanic membrane:80％ was located in the anterior inferior of parstensamembranaetympani. The size of ruptured eardrums:95％ of the ruptured eardrums was less than 5 mm, and 5 ％ was more than 5 mm in gradually pressure group;40％ was more than 5 mm in constant pressure group,the difference between the two groups was significant. The type of ruptured eardrums:triangular in shape, strip-type and the large size and irregular laceration account for 75％, 20％and 5％ in gradually pressure group,and 15％, 15％ and 70％ in constant pressure group, respectively, the difference between the two groups was significant. The edge was rough in about 95 ％ of tympanic membrane,less bleeding,and no damage. Conclusion The result of the indirect tympanic membrance perforation get close relationship with the power, the individual difference of the tympanic membrance, the structural characteritics of the eardrum. There was a clear difference between the indirect and direct tympanic membrance perforation.%目的 探讨间接性鼓膜裂伤的形成机制及其特有的临床表现.方法 将20只成年猫随机均分为两组,逐渐加压组和恒压组各10只猫20耳.观察间接性鼓膜裂伤的成伤过程,及穿孔的部位、大小、形状,裂伤区出血状态,外耳道损伤情况等.结果 两组猫耳鼓膜破裂部位:80%位于鼓膜紧张部前下.鼓膜破裂大小:逐渐加压组中,95%为＜5 mm的穿孔,仅有5%为＞5 mm的较大鼓膜穿孔;在恒压组中,40%为＞5 mm 的鼓膜穿孔,两组比较差异有统计学意义.鼓膜穿孔类型:逐渐加压组中,75%为三角形、20%为条形裂伤,仅有5%为大而不规则裂伤;在恒压组中,有15%为三角、15%为条形裂伤,70%为鼓膜不规则较大穿孔,两组比较差异有统计学意义.两组猫耳中95%的裂孔边缘粗糙,边缘出血量少,外耳道无损伤.结论 间接性鼓膜裂伤的形成与致伤力大小、鼓膜个体差异、鼓膜自身结构特点密切相关.间接性鼓膜裂伤与直接鼓膜裂伤的形成有着明显差别.
展开▼
