[Correlation of temporal bone HRCT, SLC26A4 gene and hearing loss in enlarged vestibular aqueduct].

Objective:To explore the correlation between high-resolution computed tomography（HRCT） of temporal bones, SLC26A4 gene mutation and hearing loss in patients with enlarged vestibular aqueduct（EVA）. Methods:The medical records of 257 subjects hospitalized for moderate to severe sensorineural hearing loss in the Department of Otolaryngology Head and Neck Surgery, Hainan General Hospital between May 2018 to 2021 were retrospectively reviewed. All included cases received audiological examination, HRCT scanning of temporal bones and SLC26A4 gene sequencing. According to the Valvassori standard, cases with the diameter from the common peduncle of the semicircular canal to the midpoint of the outer orifice of the vestibular aqueduct（MP） over 1.5 mm, or the diameter of the outer orifice of the vestibular aqueduct（OP） more than 2.0 mm were diagnosed as EVA. There were 22 cases（44 ears） of EVA in the study, aged between 6 months to 17 years old. Based on the hearing changes at birth and during growth, 18 ears of which were classified into the stable hearing group, while the other 26 ears in the unstable group. Moreover, all involved cases were grouped by MP（1.5 to <3.0 mm and ≥3.0 mm） and OP（2.0 to <4.0 mm and ≥4.0 mm）. SPSS 25.0 software was applied in the study. The correlation between hearing loss and MP and OP was analyzed. The results of HRCT of temporal bones and SLC26A4 gene sequencing were compared as well. Results:Though the size of MP and OP was not statistically different between the stable and hearing groups in EVA ears（P>0.05）, it was significantly correlated with the severity of hearing loss（P<0.05）. Of the 22 EVA patients diagnosed by HRCT, 21 were positive for SLC26A4 gene mutation. The positive rate of EVA by SLC26A4 gene sequencing was highly consistent with HRCT（Kappa=0.975）. Conclusion:The size of MP and OP in EVA patients was related to the degree of hearing loss, but not to the stable nature of hearing loss. Temporal bone HRCT scanning and SLC26A4 gene sequencing are highly consistent in the diagnosis of EVA. The latter has no radiation and can be combined with hearing screening for early diagnosis of EVA.目的：探讨前庭水管扩大（EVA）患者颞骨高分辨率CT（HRCT）和SLC26A4基因突变及听力损失之间的相关性。 方法：收集2018年5月—2021年5月海南省人民医院耳鼻咽喉头颈外科257例中度以上听力损失患者的临床资料，所有患者均行常规主客观听力学检查、颞骨HRCT检查及SLC26A4基因检测，按Valvassori标准测量半规管总脚到前庭水管外口中点处直径（MP）超过1.5 mm或前庭水管外口直径（OP）超过2.0 mm，符合EVA的患者22例（44耳），年龄6个月～17岁，根据出生时听力、成长过程中听力变化情况分为听力稳定组（18耳）和不稳定组（26耳）。根据MP大小分为1.5～<3.0 mm组和≥3.0 mm组，根据OP大小分为2.0～<4.0 mm组和≥4.0 mm组。采用SPSS 25.0软件分析EVA患者听力损失与其MP和OP的相关性，同时比较EVA患者颞骨HRCT和SLC26A4基因检测二种诊断方法。 结果：EVA患耳的MP和OP大小在听力稳定组和不稳定组之间差异无统计学意义（P>0.05），MP和OP大小与听力损失程度具有明显相关性（P<0.05）。HRCT诊断的22例EVA患者中SLC26A4基因突变阳性21例，SLC26A4基因检测对EVA的确诊率和HRCT诊断结果具有高度一致性（Kappa=0.975）。 结论：EVA患者MP和OP大小与听力损失程度相关，但与听力损失是否稳定无关。颞骨HRCT检查与SLC26A4基因检测对EVA患者诊断高度一致，后者无辐射，可联合听力筛查用于EVA患者早期诊断。.