2.2 | Participants
645 children diagnosed with
bilateral severe or profound sensorineural hearing loss in the Removed
for Blind Peer Review were recruited in this study. Children were
excluded if they had: 1) unable to completed the examination or
evaluation; and 2) evidence of major secondary disabilities such as
white matter diseases, nervous system disease, physical disability.
Accordingly, 500 children were selected and all they completed auditory
evaluation, CT scan of the temporal bone and developmental evaluation.
The CT scan was measured by the same specialized radiologist and the
vestibular aqueduct, inner structure and internal auditory canal were
paid special attention. The vestibular aqueduct was regarded as enlarged
when midpoint diameter of vestibular aqueduct was >1.5 mm
in the axial view in a computed tomography scan (2). LVAS could be
diagnosed when enlarged vestibular aqueduct was a separate anomaly and
those combined with other inner ear malformations were excluded in this
study. Representative examples of CT are shown in FIGURE 1.
According to the results of CT scan, 70 children diagnosed with isolated
enlarged vestibular aqueduct were recruited as LVAS group. Among the
remaining subjects without enlarged vestibular aqueduct, we used
propensity matched analysis (PSM), matching the factors of gender, age
and hearing threshold, at the ration of 1:1, to screen the candidate for
non-LVAS subjects. Finally, 70 gender-, age-, and auditory- matched
children were recruited as non-LVAS group.