Ghadiali Samir N, Swarts J Douglas, Doyle William J
Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Ann Otol Rhinol Laryngol. 2003 Aug;112(8):704-11. doi: 10.1177/000348940311200810.
Several physiological functions, such as regulating middle ear (ME) pressure and clearing ME fluid into the nasopharynx, require an opening of the collapsed eustachian tube (ET). The ability to perform these functions has been related to several mechanical properties of the ET: opening pressure (Popen), compliance (ETC), and hysteresis (eta). These global properties may be influenced by the mechanics of the surrounding tissue and/or the mucosa-air interface. In this study, we investigated the influence of tissue mechanics by paralyzing the right tensor veli palatini (TVP) muscle in 12 cynomolgus monkeys via botulinum toxin injection. A previously developed modified forced-response protocol was used to measure Popen, ETC, and eta under normal conditions and after muscle paralysis. The loss of muscle tone and/or stiffness resulted in a significant decrease in Popen (p < .01) and a significant increase in ETC (p < .01). In addition, muscle paralysis reduced the viscoelastic properties of the TVP muscle and therefore resulted in a significant decrease in eta (p < .05). A comparison with previous measurements on the influence of surface tension mechanics indicates that the ET's compliance is primarily determined by tissue elastic properties. The ET hysteresis, however, is equally affected by viscoelastic tissue properties and surface tension hysteretic properties. Knowledge of how these physical components affect the global mechanical environment may lead to improved treatments for ET dysfunction that target the underlying mechanical abnormality.
一些生理功能，如调节中耳（ME）压力以及将中耳内的液体引流至鼻咽部，需要塌陷的咽鼓管（ET）打开。执行这些功能的能力与咽鼓管的多种力学特性有关：开放压力（Popen）、顺应性（ETC）和滞后现象（eta）。这些整体特性可能会受到周围组织和/或黏膜-空气界面力学的影响。在本研究中，我们通过向12只食蟹猴注射肉毒杆菌毒素使右侧腭帆张肌（TVP）麻痹，以此来研究组织力学的影响。采用先前开发的改良强制反应方案，在正常条件下以及肌肉麻痹后测量Popen、ETC和eta。肌张力和/或刚度的丧失导致Popen显著降低（p < 0.01），ETC显著增加（p < 0.01）。此外，肌肉麻痹降低了TVP肌肉的粘弹性特性，因此导致eta显著降低（p < 0.05）。与先前关于表面张力力学影响的测量结果相比表明，咽鼓管的顺应性主要由组织弹性特性决定。然而，咽鼓管滞后现象同样受到粘弹性组织特性和表面张力滞后特性的影响。了解这些物理成分如何影响整体力学环境，可能会带来针对潜在力学异常的更有效的咽鼓管功能障碍治疗方法。
