在根治术或改良根治术等开放手术采用表面进路(耳内或后上)时,必须保证术腔深部的通风良好,这只须借耳道成形术或改良的耳甲成形术即可做到。皮肤表面需要通风,否则可能转化形成胆脂瘤。换言之,它与 V(气流体积,由耳道耳甲成形术决定)、S(与气流接触的皮肤表面积)有关。对易发生胆脂瘤的患者 V 值要较一般人大些,以保证皮肤更好的通风。可借封闭术式减少 S 值,也可借耳道耳甲成形术增加 V 值。多数病例术腔不太大,采用小皮瓣三瓣耳道成形 In open surgery such as radical mastectomy or modified radical mastectomy (otic or posterior), ventilation must be ensured in the deep part of the lumen, which can only be achieved by ear canal angioplasty or modified otosurgery To The skin surface needs ventilation, otherwise it may turn into the formation of cholesteatoma. In other words, it is related to V (volume of air flow, determined by otorhinolaryngoplasty), S (surface area of ​​the skin in contact with airflow). V-value for patients prone to cholesteatoma than the average person to ensure better ventilation of the skin. Can be closed by reducing the S value, but also can increase the V value by ear canal forming. The majority of cases of surgery is not too large, with three flap ear canal forming