Abstract

OBJECTIVE: The study aimed to understand the causes of chronic otitis media (COM) with unilateral or bilateral cholesteatoma by examining the eustachian tube (ET) and mastoid ventilation from preoperative high-resolution temporal computed tomography (HRTCT) scans.

METHODS: In this retrospective case-control study, COM patients with cholesteatoma who underwent preoperative HRTCT scanning between January 2021 and December 2023 were analyzed. The study included 102 ears of 51 participants (31 males, 20 females; mean age: 35.7±14.0 years; range, 18 to 65 years). The participants were divided into three groups, each with 17 individuals: unilateral COM with cholesteatoma, bilateral COM with cholesteatoma, and a healthy control group. Variables, including Reid plane-ET angle, tubotympanic angle (TTA), ET length, ET tympanic orifice and isthmus widths, and mastoid ventilation type and volume, were examined in CT images.

RESULTS: The mean left TTA (p=0.045) was higher in the unilateral cholesteatoma group compared to the control group (148.88±5.30 and 144.24±6.51, respectively; p=0.045). The bilateral cholesteatoma group exhibited higher values for right and left ET isthmus widths (p=0.015 and p=0.014, respectively). The control group had significantly higher mastoid volumes compared to groups with cholesteatoma (p<0.001). Type 3 mastoid distribution was notably higher in groups with cholesteatoma (p<0.001). In the control group, the mean right and left ET angles were 25.13±3.35° and 24.67±3.38°, respectively.

CONCLUSION: Tubotympanic angle and ET isthmus width may be a potential marker for cholesteatoma. Large-scale studies targeting the anatomy and function of the isthmus in combination with mastoid and ET radiomorphological data and clinical scores using standardized protocols may improve treatment strategies.