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Singapore Medical Journal Aug 2023A retrospective study (2011 to 2018) was conducted to evaluate the management of cholesteatomas with labyrinthine fistulae (LFs), clinical characteristics and...
INTRODUCTION
A retrospective study (2011 to 2018) was conducted to evaluate the management of cholesteatomas with labyrinthine fistulae (LFs), clinical characteristics and postoperative hearing outcomes in a hospital.
METHODS
Demographic data of patients with primary middle ear mastoidectomies for cholesteatoma were extracted. Preoperative high-resolution computed tomography (HRCT) temporal bone and intraoperative findings, and hearing levels preoperatively and postoperatively were evaluated.
RESULTS
Of the middle ear cholesteatomas, 15.6% (n = 14) of ears were complicated by LF. HRCT scans showed 92.9% sensitivity and 94.7% specificity in the identification of LFs. Intraoperative findings of LFs include stapes erosion (78.6%), malleus erosion (78.6%), incus erosion (92.9%), dehiscence of tegmen tympani (28.6%) and tympanic facial canal (64.3%). Compared to the non-LF group, the LF group showed significantly higher incidence of stapes erosion (P < 0.001), tegmen tympani dehiscence (P = 0.016) and semicircular canal dehiscence (P < 0.001). Matrix was removed completely in 85.7% (n = 12) and was left behind in 14.3% (n = 2) of ears. Also, 21.5% (n = 3) had preoperative dead ears. Postoperative hearing results had a mean follow-up time of 2.1 (standard deviation 1.5, range 0.14-4.84) years. In the matrix removal group (n = 9), 77.9% had unchanged hearing levels, 11.1% showed improvement and 11.1% showed decrease in hearing levels. The matrix preservation group (n = 2) had deteriorated hearing levels.
CONCLUSION
Preservation of hearing in LFs is possible with cautious matrix removal. Despite matrix preservation to preserve hearing in large LFs, our patients' hearing deteriorated postoperatively. Longer follow-up of hearing with matrix preservation may show poorer hearing outcomes.
PubMed: 37675676
DOI: 10.4103/singaporemedj.SMJ-2021-377 -
Nature Communications Oct 2023The middle ear ossicles in modern mammals are repurposed from postdentary bones in non-mammalian cynodonts. Recent discoveries by palaeontological and embryonic studies...
The middle ear ossicles in modern mammals are repurposed from postdentary bones in non-mammalian cynodonts. Recent discoveries by palaeontological and embryonic studies have developed different models for the middle ear evolution in mammaliaforms. However, little is known about the evolutionary scenario of the middle ear in early therians. Here we report a detached middle ear preserved in a new eutherian mammal from the Early Cretaceous Jehol Biota. The well-preserved articulation of the malleus and incus suggest that the saddle-shaped incudomallear joint is a major apomorphy of Early Cretaceous eutherians. By contrast to the distinct saddle-like incudomallear articulation in therians, differences between the overlapping versus the half-overlapping incudomallear joints in monotremes and stem mammals would be relatively minor. The middle ear belongs to the microtype by definition, indicating its adaptation to high-frequency hearing. Current evidence indicates that significant evolutionary innovations of the middle ear in modern therians evolved in Early Cretaceous.
Topics: Animals; Biological Evolution; Phylogeny; Eutheria; Mammals; Ear, Middle; Fossils
PubMed: 37884521
DOI: 10.1038/s41467-023-42606-7