真珠腫性中耳炎に対する外耳道再建型鼓室形成術の聴力成績

Abstract

While the hearing outcome of patients undergoing a tympanoplasty with canal reconstruction is generally thought to be inferior to that of patients undergoing a canal-up tympanoplasty, a direct comparison of these two procedures, performed by the same operator, has not been reported. Consequently, we compared the hearing outcomes of these two techniques and discussed the postoperative complications that could accompany the procedures. Hearing was evaluated in 52 ears with middle ear cholesteatoma. Using the postsurgical hearing result assessment criteria published by the Japanese Society of Otology in 2000, hearing was then evaluated again at least 6 months after surgery. When the data was analyzed according to the type of operation, the success rates (as determined using the above assessment criteria) were 78.6% for type I, 88.5% for modified type III, and 50.0% for modified type IV. The success rate for the modified type III operations was superior to that of the modified type IV operations, and the incidence of a postoperative air-bone gap in the type IV tympanoplasties was significantly larger than that in other groups. Procedures involving external auditory canal surgery can be particularly problematic for the treatment of cholesteatoma. In this series, the same author (KH) performed all the canal-up tympanoplasty procedures that took place during 1990-1996, and all other tympanoplasties, mainly canal reconstruction procedures, that took place during 1998-2001. The success rate was 68.4% (13/19) for the canal-up tympanoplasties, 100% (8/8) for the atticotomies and 76% (19/25) for the canal wall reconstructions. The postoperative success rate in the atticotomy group was significantly higher than the rates of the other groups. Among the canal reconstructive tympanoplasty procedures, a second exploratory surgery was performed in 15/24 cases, and residual cholesteatoma was observed in 3 cases. The major postoperative complications were epitympanic pocket formation (12/24) and taste disturbances, caused by chordal damage (2/24). These findings indicate that tympanoplasties with canal reconstruction improve the hearing outcome, compared with the outcome of canal-up tympanoplasties. However, epitympanic retraction pocket formation, resulting in recurrent cholesteatoma, is a possible complication of both surgical procedures, and new approaches or techniques should be sought to minimize such postoperative changes.