Acquired fibrotic atresia of the external auditory canal

BACKGROUND: 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. PATIENTS: 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. RESULTS: 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. CONCLUSIONS: 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.