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.