Lesser T H, Williams K R, Skinner D W
Department of Otolaryngology, University Hospital of Wales, Heath Park, Cardiff.
Clin Otolaryngol Allied Sci. 1988 Oct;13(5):375-80. doi: 10.1111/j.1365-2273.1988.tb00769.x.
This paper deals with grommet induced tympanosclerosis. In the first part, patients from a controlled trial of the treatment of bilateral glue ear using unilateral grommet insertion are reviewed 15 years later. Tympanosclerosis due to grommet insertion is summated using computer graphics. Two areas of maximal tympanosclerosis are found, anteriorly and posteriorly midway between the annulus and the umbo. These maximal areas join inferiorly in the classical horse shoe shape. In an attempt to identify reasons for this distribution, the structure of the lamina propria is reviewed, and the changes that occur in tympanosclerosis considered. With this in mind, the tympanic membrane is modelled using finite element methodology to determine the areas of maximal shear stresses. These are found to be in the same position as tympanosclerosis. Such stresses would be increased by the weight of a grommet in situ. These stresses will damage the fibrils interconnecting between the fibrous layers of the lamina propria and this may lead to tympanosclerosis. This raises the question of whether a lighter grommet would decrease the incidence of grommet-induced tympanosclerosis.
本文探讨鼓膜通气管引发的鼓室硬化症。第一部分回顾了15年前一项使用单侧鼓膜通气管插入术治疗双侧胶耳的对照试验中的患者情况。利用计算机图形技术总结了由鼓膜通气管插入导致的鼓室硬化症情况。发现了两个鼓室硬化症最严重的区域，分别位于鼓膜环和鼓膜脐之间的前中部和后中部。这些最严重的区域在下方连接成典型的马蹄形。为了找出这种分布的原因，回顾了固有层的结构，并考虑了鼓室硬化症中发生的变化。基于此，使用有限元方法对鼓膜进行建模，以确定最大剪应力区域。发现这些区域与鼓室硬化症的位置相同。通气管在原位的重量会增加此类应力。这些应力会损害固有层纤维层之间相互连接的纤维，这可能导致鼓室硬化症。这就提出了一个问题，即更轻的鼓膜通气管是否会降低鼓膜通气管引发的鼓室硬化症的发生率。
