University Hospital Carl Gustav Carus, Department of Otorhinolaryngology, Head and Neck Surgery, Ear Research Center Dresden (ERCD).
University Hospital Carl Gustav Carus, Department of Otorhinolaryngology, Head and Neck Surgery, Ear Research Center Dresden (ERCD).
Hear Res. 2023 May;432:108737. doi: 10.1016/j.heares.2023.108737. Epub 2023 Mar 21.
In reconstructive middle ear surgery, acoustic quality has received a high level of attention in recent years. Careful intraoperative selection and positioning of passive middle ear prostheses during tympanoplasty with ossiculoplasty is essential to ensure satisfactory sound transmission and postoperative hearing outcome. The reconstruction quality of the ossicular chain (OC) can be evaluated intraoperatively using a surgical assistance system which is based on a real-time monitoring system (RTM system) that acquires the transmission (middle ear transfer function (METF)) with electromagnetic excitation of the OC. In this experimental study, the METF with electromagnetic excitation of the (reconstructed) OC was compared to usual acoustic excitation and the benefit of the RTM system was investigated for the implantation of partial (PORP) and total (TORP) prostheses.
Laser Doppler vibrometry (LDV) was used to measure the middle ear transfer function (METF) in 18 human temporal bones (TB). The RTM system uses electromagnetic excitation of the OC with a magnet placed on the umbo. Comparatively, measurements with the usual acoustical excitation, using an earphone in the external auditory canal, were performed. The measurements began with the intact OC, followed by real-time monitoring guided OC reconstruction with PORP and TORP. In addition, during the simulation of an intraoperative setting, the influence of the influence of opening (tympanomeatal flap lifted and pushed anteriorly) and closing (tympanomeatal flap folded back) the tympanic membrane on the measurements with the RTM system was determined.
Electromagnetic and acoustic excitation of the intact and the reconstructed OC provided comparable METF. The application of the RTM system significantly improved the quality of the OC reconstruction. The METF increased by up to 10 dB over the entire frequency range during implantation of the PORP with positioning control by the RTM system. When using the TORP, the METF could be improved by up to 15 dB. The opening of the tympanomeatal flap did not affect the measurements with the RTM system at the reconstructed OC.
In this TB study, we demonstrated that the quality of OC reconstruction (improved METF as a benchmark for improved transmission) could be significantly increased by means of a RTM system. Intraoperative studies should now be conducted to investigate to which quantitative extent the intraoperative reconstruction quality can be improved and whether or not this improvement also manifests in an increased (long-term) hearing outcome. This will enable conclusions to be drawn about the contribution of the intraoperative reconstruction quality to the (long-term) hearing outcome in the context of the conglomerate of various factors influencing the postoperative hearing outcome.
在重建性中耳手术中，近年来，人们对声学质量给予了高度关注。在鼓室成形伴听骨链重建术中，仔细选择和定位被动中耳赝复体至关重要，这有助于确保满意的声音传递和术后听力效果。使用手术辅助系统（基于实时监测系统（RTM 系统）的电磁激励听骨链的系统）可在术中评估听骨链（OC）的重建质量，该系统可以获取电磁激励 OC 时的中耳传递函数（中耳传递函数（METF）。在这项实验研究中，将电磁激励的 OC 的 METF 与通常的声学激励进行了比较，并研究了 RTM 系统在植入部分（PORP）和完全（TORP）假体中的益处。
使用激光多普勒测振仪（LDV）测量 18 个人类颞骨（TB）的中耳传递函数（METF）。RTM 系统使用放置在耳屏上的磁铁来电磁激励 OC。相比之下，使用外耳道中的耳机进行了通常的声学激励测量。测量从完整的 OC 开始，然后在实时监测引导下进行 PORP 和 TORP 的 OC 重建。此外，在模拟术中设置的过程中，确定了 RTM 系统测量时鼓膜张开（提起并向前推鼓窦瓣）和闭合（将鼓窦瓣折回）的影响。
电磁和声学激励完整和重建的 OC 提供了可比的 METF。RTM 系统的应用显著提高了 OC 重建的质量。通过 RTM 系统的定位控制，PORP 植入时的 METF 可在整个频率范围内提高 10dB。当使用 TORP 时，METF 可提高 15dB。鼓窦瓣的张开不会影响 RTM 系统在重建 OC 上的测量。
在这项 TB 研究中，我们证明了 RTM 系统可显著提高 OC 重建质量（以提高传输为基准的 METF）。现在应该进行术中研究，以研究术中重建质量可以提高多少定量程度，以及这种提高是否也表现为增加（长期）听力结果。这将使我们能够根据影响术后听力结果的各种因素的组合，得出术中重建质量对（长期）听力结果的贡献的结论。
