4.2.3. Influence of osseous tissue on hearing
This study found that the fusion and fixation of the malleus and incus occurred in five of the seven patients with EC-LSC. Ossicle fusion causes a loss of mixed hearing that is primarily conductive in nature. With the removal of the fused ossicles and the use of appropriate ossicular prostheses (PORP/TORP), the postoperative hearing of patients can be improved to varying extents.
Labyrinthine fistulas are also considered a key influencing factor for postoperative hearing. Geerse et al. found that the sizes of labyrinthine fistulas correlated with postoperative hearing loss.12 Hence, opening the membranous labyrinth resulted in significantly worse postoperative BC threshold and can be seen as a predictive parameter. For the two cases of labyrinthine fistulas considered in this study, the timely discovery and patching of the fistulas during the surgery and the early administration of dexamethasone prevented the postoperative BC threshold levels from changing significantly. This suggests that the methods employed to address the fistulas helped to stabilize the patients’ hearing.