Strohm M
HNO-Klinik des Diakonissenkrankenhauses Karlsruhe, Stuttgart, Germany.
Laryngorhinootologie. 2002 Jan;81(1):8-13. doi: 10.1055/s-2002-20119.
There are very few communications on this pathologic entity, which is also called "postinflammatory medial meatal fibrosis" (PIMMF), its etiology and the adequate therapy. Apparently the cause is a chronic inflammation (or chronic ekzema) of the medial part of the external meatus or also a long-lasting otorrhea in chronic otitis media. The stratified epithelium of the eardrum and of the adjacent bony meatus is destroyed and replaced by fibrotic tissue. The lateral part of the auditory canal remains open and has the form of the finger of a glove, it may contain granulations, but often it is lined with a smooth stratified epithelium. A severe conductive hearing loss is the result of this anomaly.
During the last 10 years we operated on 46 patients (52 ears) for this pathology: after retroauricular opening, which allows the best control of the anterior tympanomeatal angle, the fibrotic tissue was removed keeping the lamina propria intact. The bony canal was widened, if necessary. The eardrum and the bony canal were covered with split skin graft from the retroauricular region, then the canal filled with an antibiotic package for 3 weeks.
Underneath the fibrotic tissue we detected 3 cholesteatomata of the annular region, so it is important to remember, that the atresia may also cover a dangerous pathology. 6 times a second operation was necessary, besides that, we observed 14 recurrencies. All other patients had a wide epithelialized ear canal, their conductive hearing loss disappeared, and the results were stable over several years. Bacteriological and histological examinations were not helpful to clear up the etiology of this disease.
Surgery is the treatment of choice of the acquired atresia of the external meatus. We suppose that in these patients a individual disposition causes the formation of this excessive fibrosis, which has some similarity with keloid formation.
关于这种病理实体，即“炎症后耳道内侧纤维化”（PIMMF）、其病因及适当治疗的相关报道非常少。显然，病因是外耳道内侧的慢性炎症（或慢性湿疹），或者慢性中耳炎的长期耳漏。鼓膜和相邻骨质耳道的复层上皮被破坏，取而代之的是纤维组织。耳道外侧部分保持开放，呈手套指状，可能含有肉芽组织，但通常内衬光滑的复层上皮。这种异常会导致严重的传导性听力损失。
在过去10年中，我们对46例患者（52耳）进行了针对这种病理情况的手术：在耳后切开后，这样能最佳控制鼓室耳道前角，切除纤维组织，同时保持固有层完整。必要时扩大骨质耳道。用耳后区域的中厚皮片覆盖鼓膜和骨质耳道，然后在耳道内放置抗生素包3周。
在纤维组织下方我们发现了3例环形区域胆脂瘤，所以必须记住，闭锁也可能掩盖一种危险的病理情况。有6例需要二次手术，此外，我们观察到14例复发。其他所有患者的耳道上皮化良好，传导性听力损失消失，且结果在数年中保持稳定。细菌学和组织学检查对明确该疾病的病因并无帮助。
手术是后天性外耳道闭锁的首选治疗方法。我们推测，在这些患者中，个体易感性导致了这种过度纤维化的形成，这与瘢痕疙瘩的形成有一些相似之处。
