Department of Otolaryngology and Head and Neck Surgery, Beijing Tong Ren Hospital, Capital Medical University, No 1, Dongjiaominxiang, Dongcheng District, Beijing, 100730, China.
Key laboratory of Otolaryngology and Head and Neck Surgery, Ministry of Education, 11th floor, no. 8, Chongwenmen Inner Street, Beijing, 100730, China.
J Otolaryngol Head Neck Surg. 2020 Aug 8;49(1):57. doi: 10.1186/s40463-020-00452-3.
Malformations of the temporal bone present different challenges to the implantation of a transcutaneous active bone conduction device, such as Bonebridge (Med-el, Innsbruck, Austria). This study aims to describe the benefits of high-resolution computed tomography (HRCT) in preoperative assessment and to analyze whether characteristics of the mastoid process, intraoperative compression of the dura or sigmoid sinus, and the use of the Lifts system, lead to differences in audiological performance after implantation.
We examined 110 cases of congenital microtia. The structure of the temporal bone was examined using HRCT and a 3D simulation software program. The mean anteroposterior mastoid bone thickness from the external auditory canal to the sigmoid sinus was measured (a measurement referred to as "AP", hereafter). Sound field threshold (SFT), speech reception threshold (SRT) in noise, and word recognition score (WRS) in quiet, before and after implantation, were also measured. Independent variables were recorded in all patients: mastoid type (well pneumatized or poorly pneumatized), the presence of dural or sigmoid sinus compression, and the use of the Lifts system.
We found that the mean AP in the non-compression group was 16.2 ± 2.3 mm and in the compression group, 13.1 ± 2.9 mm (p < 0.001). We analyzed the hearing improvement of patients grouped by mastoid development, dural or sigmoid sinus compression, and use of the Lifts system, and found that these factors did not interact and that they had no influence on the hearing outcomes (p > 0.05).
The AP dimension in the non-compression group was significantly larger than that in the compression group. This finding combined with the ROC curve analysis revealed the AP dimension was a high-accuracy predictor of potential surgical complications involving the dura and sigmoid sinus compression. Further analysis revealed that there was no interaction between the chosen variables: mastoid type, dural or sigmoid sinus compression, and the use of the Lifts system, and that all of these factors had no significant impact on hearing performance. Bonebridge was shown to produce effective and stable bone conduction and to improve patients' hearing performance.
颞骨畸形给经皮主动骨导装置（如 Bonebridge，Med-el，因斯布鲁克，奥地利）的植入带来了不同的挑战。本研究旨在描述高分辨率计算机断层扫描（HRCT）在术前评估中的益处，并分析乳突形态、术中硬脑膜或乙状窦受压以及使用 Lifts 系统是否会导致植入后听力表现的差异。
我们检查了 110 例先天性小耳畸形患者。使用 HRCT 和 3D 模拟软件程序检查颞骨结构。从外耳道到乙状窦测量前后乳突骨的平均厚度（称为“AP”）。测量植入前后声场阈值（SFT）、噪声下言语接受阈值（SRT）和安静环境下言语识别率（WRS）。所有患者记录了以下独立变量：乳突类型（充气良好或充气不良）、硬脑膜或乙状窦受压、以及使用 Lifts 系统。
我们发现无压迫组的平均 AP 为 16.2±2.3mm，压迫组为 13.1±2.9mm（p<0.001）。我们分析了根据乳突发育、硬脑膜或乙状窦压迫以及使用 Lifts 系统分组的患者的听力改善情况，发现这些因素之间没有相互作用，对听力结果没有影响（p>0.05）。
无压迫组的 AP 尺寸明显大于压迫组。这一发现结合 ROC 曲线分析表明，AP 尺寸是预测硬脑膜和乙状窦受压等潜在手术并发症的高精度指标。进一步分析表明，所选变量之间没有相互作用：乳突类型、硬脑膜或乙状窦压迫以及使用 Lifts 系统，所有这些因素对听力表现均无显著影响。Bonebridge 产生了有效的和稳定的骨导，并改善了患者的听力表现。
