Palva T, Northrop C, Ramsay H
Department of Otolaryngology, University of Helsinki, Finland.
Am J Otol. 2000 Jan;21(1):62-70.
The tissue-fixed amniotic fluid cellular content (AFCC) in the middle ear and mastoid antrum causes foreign body type reactions that may later severely restrict the aeration pathways to the main attic and to Prussak's space.
It was shown by Aschoff 100 years ago that AFCC remained in the neonate ears and caused sterile otitis media. Recent data show that children born through thick meconium are at risk for large quantities of AFCC entering the middle ear cleft, the ensuing inflammatory reaction being related to the amount of AFCC. Spread of AFCC in the neonate occurred along the aeration pathways with corresponding tissue fixation but further systematic data in young infants are lacking.
Five temporal bones of three infants aged 2 to 4 months were embedded in celloidin, serially sectioned at 20 microns, and every 10th section stained with Hematoxylin and eosin and mounted on slides. All slides were studied and relevant details of aeration pathways and all compartments photographed.
The histologic changes were characterized by the development of masses of pseudocystic granulation tissue, with some remnants of the original AFCC, mainly in the form of fragments of hair. The tympanic isthmus was involved to varying extent, maximally to half of its size. Posterior tympanum and the stapes region had masses of fresh granulation tissue, the maturing of which might cause marked indrawing of the posterior pars tensa and further reduction of the tympanic isthmus. Aeration of Prussak's space was severely involved in two bones, favored by the narrow pathway through the posterior pouch. Features of recent acute or secretory otitis media were associated with the early changes caused by AFCC.
The granulation tissue in this age group is immature and its final fate is decided by the nature of the future ear disease. If the AFCC contamination is slight, the granulation tissue after maturing may appear only in the form of thin cords and sheets, a frequent chance finding in ear surgery. Large amount of AFCC may lead to chronic inflammation, which may predispose the child to recurring middle ear infections during infancy. Further histologic and clinical studies in older infants and young children are needed to find out the final outcome after a massive AFCC contamination of the new-born middle ear.
中耳和乳突窦内组织固定的羊水细胞成分（AFCC）会引发异物型反应，这可能会在日后严重限制通向鼓室上隐窝和普鲁萨克间隙的通气路径。
100年前阿绍夫证实，AFCC会残留在新生儿耳内并引发无菌性中耳炎。近期数据表明，通过浓稠胎粪分娩的儿童存在大量AFCC进入中耳裂的风险，随之而来的炎症反应与AFCC的数量有关。AFCC在新生儿体内沿通气路径扩散并伴有相应的组织固定，但缺乏关于幼儿的进一步系统性数据。
将3名2至4个月大婴儿的5块颞骨用火棉胶包埋，切成20微米厚的连续切片，每隔10张切片用苏木精和伊红染色并制成载玻片。研究所有载玻片，拍摄通气路径和所有腔隙的相关细节。
组织学变化的特征是出现大量假囊肿性肉芽组织，伴有一些原始AFCC的残余物，主要呈毛发碎片的形式。鼓室峡部不同程度地受累，最大可达其大小的一半。鼓室后部和镫骨区域有大量新鲜肉芽组织，其成熟可能导致紧张部后份明显内陷，进而使鼓室峡部进一步变窄。在两块颞骨中，普鲁萨克间隙的通气严重受累，通过后袋的狭窄路径有利于这种情况发生。近期急性或分泌性中耳炎特征与AFCC引起的早期变化有关。
该年龄组的肉芽组织不成熟，其最终转归取决于未来耳部疾病的性质。如果AFCC污染轻微，成熟后的肉芽组织可能仅以细索和薄片的形式出现，这在耳部手术中是常见的偶然发现。大量AFCC可能导致慢性炎症，这可能使儿童在婴儿期易反复发生中耳感染。需要对较大婴儿和幼儿进行进一步的组织学和临床研究，以明确新生儿中耳大量AFCC污染后的最终结局。
