Pharyngeal wall fold influences on the collapsibility of the pharynx
Pharyngeal wall fold influences on the collapsibility of the pharynx
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DOI：
10.1016/j.mehy.2012.05.040
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发表时间：
2012-09-01
影响因子：
4.7
通讯作者：
Kairaitis, Kristina
中科院分区：
文献类型：
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作者：
Kairaitis, Kristina
阻塞性睡眠呼吸暂停（OSA）是一种以睡眠期间反复出现咽部阻塞为特征的疾病。咽是一个中空的肌肉管，内衬上皮，执行呼吸和吞咽的竞争功能，其中需要打开，而吞咽则需要关闭。尚未考虑到管腔尺寸发生这些巨大变化的机械过程，但在其他生物管中，例如食道和支气管，气道变窄和闭合是通过粘膜表面的折叠而发生的。使管塌陷所需的跨壁压力 (P) 与塌陷期间形成的折叠数量 (n) 相关，公式为 P = n(2) - 1，因此在变窄和闭合期间形成的折叠越多，使管塌陷所需的跨壁压力就越大。在生物力学模型中，支气管气道被建模为具有内上皮衬里和外层肌肉的两层管。这些模型预测，折叠数量将随着外层的增厚和硬化而减少，同时伴随着塌陷性的增加。我们假设，与其他生物管类似，咽通过管表面的折叠而变窄和关闭，并且咽也可以建模为 2 层管。我们进一步假设，与健康受试者相比，美国受试者在狭窄和闭合过程中咽壁褶皱较少，并且褶皱数量的减少将导致咽部塌陷性增加。在缺乏肌肉活动的情况下，与健康受试者相比，美国受试者的咽部塌陷度增加，这支持了咽部塌陷的解剖学原因。对美国受试者咽部上皮的组织病理学研究表明，与年龄匹配的受试者相比，上皮表面增厚，粘膜下层水肿，上皮与粘膜下层的束缚丧失。这些变化往往会减少倍数。没有对咽部褶皱的测量，但之前的成像数据支持咽部通过折叠而变窄。这一假设为美国定义了一种新的解剖学风险。它还为美国的治疗提出了一种新的治疗范例，旨在增加狭窄和闭合过程中形成的褶皱。 Crown 版权所有 (C) 2012 由 Elsevier Ltd 出版。保留所有权利。
Obstructive sleep apnoea (OSA) is a disease that is characterised by recurrent pharyngeal obstruction during sleep. The pharynx is a hollow muscular tube lined with epithelium that performs the competing functions of breathing, where it is required to be open and swallowing where it is required to close. The mechanical process by which these large changes in luminal dimensions occur have not been considered, however in other biological tubes such as the oesophagus and the bronchial airways narrowing and closure occurs via folding of the mucosal surface. The transmural pressure (P) required to collapse a tube is related to the number of folds (n) formed during collapse by the equation P = n(2) - 1, so that the more folds formed during narrowing and closure, the greater the transmural pressure required to collapse the tube. In biomechanical models, the bronchial airway is modelled as a 2-layer tube with an inner epithelial lining and an outer layer of muscle. These models predict that fold numbers will be reduced with thickening and stiffening of the outer layer, accompanied by an increase in collapsibility. We hypothesise that, similar to other biological tubes the pharynx narrows and closes via folding of the surface of the tube, and that the pharynx can also be modelled as a 2-layer tube. We further hypothesise that when compared to healthy subjects, subjects with USA will have less pharyngeal wall folds during narrowing and closure, and that this reduction in fold numbers will contribute to an increase in pharyngeal collapsibility. In the absence of muscle activity, subjects with USA have increased pharyngeal collapsibility when compared with healthy subjects, supporting an anatomical contribution to pharyngeal collapse. Histopathological studies of the pharyngeal epithelium in subjects with USA demonstrate that, compared with age matched subjects, there is thickening of the epithelial surface with oedema of the submucosal layer, with a loss of tethering of the epithelium to the submucosal layer. These changes would tend to decrease fold numbers. There are no measurements of pharyngeal folds, however previous imaging data supports that narrowing of the pharynx occurs via folding. This hypothesis defines a novel anatomical risk for USA. It also suggests a new therapeutic paradigm for the treatment of USA, aimed at increasing the folds formed during narrowing and closure. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.