[Analyses of the factors relevant to revision tympanomastoid surgery]

To analyze factors relevant to revisional tympanomastoid surgery for chronic otitis media(COM).

The clinical data of 159 patients (159 ears), who exhibited either wet ear or relapsed after the initial operation, and were subjected to revisional tympanomastoid surgery, were retrospectively analyzed in this study. Of those 159 consecutive patients, 85 were males and 74 were females, aged 11-64 years, with a median age of 36 years old. The situations in terms of intra-operative findings, surgical procedures, change dressing post-operation, dry ear time, and the improvement of aural ability during the second operation, were recorded and analyzed.

The second surgery found that, of those 159 patients underwent the re-operation, 67 presented with cholesteatoma and 92 had no cholesteatoma. In addition, the inadequate skeletonization and insufficient opening for mastoid cavity accounted for 70.4% (112/159) of all previous operations, the external auditory canal stenosis for 98.7% (157/159), the high facial ridge leading to insufficient drainage for 61.0% (97/159), the lesion in tympanic ostium of Eustachian tube for 34.6% (55/159), the insufficient drainage due to inappropriate post-operating dressing for 5.0% (8/159), the postauricular incision for 30.8% (49/159), and the endaural incision for 69.2% (110/159). As for the re-operation of the canal wall down mastoidectomy, tympanoplasty plus plastic repairing of cavity of concha were performed in 94 cases, the modified Bondy plus plastic repairing of cavity of concha in four cases, the radical mastoidectomy plus plastic repairing of cavity of concha in 59 cases, and the simple cleaning for mastoid cavity in two cases. Since one to two weeks after the revisional operations, the post-operating dressing was performed with aid of microscopy once a week on average. The average dry ear time ranged from 2 to 6 weeks (median=3 weeks). During a period of 6-93 months for the follow-up, all patients presented with dry ears. The epithelialization of the operating cavity was well and the tympanic membranes were integrity. Neither granulation tissue nor cholesteatoma was found to reoccur. Both pure tone hearing thresholds and air-bone gap decreased in 87 cases after the revisional operation, with statistically significant different in comparison to those two parameters before the operation (P<0.05).

The primary causes responsible for the wet ear or reoccurrent cholesteatoma after tympanomastoid surgery may be related to the improper operation procedures and selection of incision, the non-standard operation, inexhaustive removal of pathological tissues, as well as the irregular postoperation change dressing, and other factors.