Tympanoplasty: long-term hearing results with incus grafts.

Abstract

AbstractThe purpose of this study was to analyze long‐term hearing results in 122 tympanoplasties with incus repositioning and in 64 tympanoplasties using a homograft incus. The mean postoperative follow‐up period in the autograft incus group was 56 months (range 18 to 95 months) and in the homograft incus group 54 months (range 28 to 87 months). Results were compared after incus placement between the tympanic membrane‐malleus complex and stapes head and placement between the tympanic membrane‐malleus complex and stapes footplate. In each group, hearing results tended to be better after malleus‐to‐stapes head placement. There was no statistically significant difference in the results achieved when similar incus placements in the two groups were compared. When the data on malleus‐to‐stapes head tympanoplasty (152 patients) and malleus‐to‐stapes footplate tympanoplasty (34 patients) in each group were combined, the results with malleus‐to‐stapes head placements were considerably better (P = 0.01). The best hearing results were not satisfactory, however, with only 54 percent of the malleus‐to‐stapes head placements achieving a socially adequate hearing level and the air‐bone gap being closed to within 15 db on only 32 percent.Hearing results were also analyzed for three subgroups. The autograft and homograft incus groups were combined. The first subgroup consisted of 30 patients who had no additional surgery other than ossicular chain reconstruction; the second subgroup consisted of 53 patients who in addition to ossicular chain reconstruction had closure of the tympanic membrane perforation; the third subgroup consisted of 103 patients who in addition to ossicular chain reconstruction had tympanic membrane perforation repair and mastoidectomy. There was no statistically significant difference in the hearing results among the three subgroups.Eleven percent of the autograft incus group and 13 percent of the homograft incus group initially had excellent hearing results and then, at various times after the operation, developed gradual deterioration in auditory acuity, which eventually resulted in an unsatisfactory hearing level. In revision operations, the most common cause of failure was non‐attachment of the incus to the head of the stapes. Second in frequency was fixation of the ossicular chain by fibrous tissue and impaction of the incus against the posterior bony annular rim. The most serious complication was depression in cochlear reserve, which occurred in 5 percent of the 186 tympanoplasties. This analysis of the long‐term hearing results achieved with incus grafts revealed that the results were far from satisfactory.