Pathogenesis and developing mechanism of pars flaccida cholesteatoma, and its prevention and surgical treatment

根据胆脂瘤的情况选择合适的手术方法（鼓室成形术）对预防胆脂瘤复发和听力的改善具有重要意义。胆脂瘤的形成和上皮的延伸被认为是恶性循环的延伸，如角质形成细胞和成纤维细胞之间的自分泌或旁分泌系统使上皮过度增殖和分化，上皮迁移受到干扰，炎症持续。在中耳粘膜上皮再生方面，我们成功地制备了培养的中耳粘膜组织，并将其移植到中耳腔内进行动物实验。也就是说，我们将兔三维培养的中耳黏膜移植到中耳腔的另一侧。再生粘膜与正常中耳粘膜在形态和生理上基本一致。

The selection of the proper operation (tympanoplasty) according to the condition of cholesteatoma is important to prevent recurrent cholesteatomas and it contoribute to the hearing improvement. The formation of cholesteatoma and extention of the epithelium are considered to be extended by vicious circle, such as the hyperprpliferation and differentiation of epithelium by autocrine or paracrine system between keratinocytes and fibroblasts, the disturbance of epithelial migration, and continuing of inflammation.Concerning the regeneration of the middle ear mucosal epithelium, we succeeded in preparing the cultured middle ear mucosal tissue and transplantation this tissue to the middle ear cavity in animal study. In other words, we transplanted the rabbit's three-dimensional cultured middle ear mucosa to the opposite side of the middle ear cavity. The regenerated mucosa was similar to the normal middle ear mucosa morphologically and physically animal study.