Häusler Rudolf, Stieger Christof, Bernhard Hans, Kompis Martin
Department of ENT, Head, Neck Surgery, Inselspital, University of Berne, Berne, Switzerland.
Audiol Neurootol. 2008;13(4):247-56. doi: 10.1159/000115434. Epub 2008 Feb 7.
A new implantable hearing system, the direct acoustic cochlear stimulator (DACS) is presented. This system is based on the principle of a power-driven stapes prosthesis and intended for the treatment of severe mixed hearing loss due to advanced otosclerosis. It consists of an implantable electromagnetic transducer, which transfers acoustic energy directly to the inner ear, and an audio processor worn externally behind the implanted ear. The device is implanted using a specially developed retromeatal microsurgical approach. After removal of the stapes, a conventional stapes prosthesis is attached to the transducer and placed in the oval window to allow direct acoustical coupling to the perilymph of the inner ear. In order to restore the natural sound transmission of the ossicular chain, a second stapes prosthesis is placed in parallel to the first one into the oval window and attached to the patient's own incus, as in a conventional stapedectomy. Four patients were implanted with an investigational DACS device. The hearing threshold of the implanted ears before implantation ranged from 78 to 101 dB (air conduction, pure tone average, 0.5-4 kHz) with air-bone gaps of 33-44 dB in the same frequency range. Postoperatively, substantial improvements in sound field thresholds, speech intelligibility as well as in the subjective assessment of everyday situations were found in all patients. Two years after the implantations, monosyllabic word recognition scores in quiet at 75 dB improved by 45-100 percent points when using the DACS. Furthermore, hearing thresholds were already improved by the second stapes prosthesis alone by 14-28 dB (pure tone average 0.5-4 kHz, DACS switched off). No device-related serious medical complications occurred and all patients have continued to use their device on a daily basis for over 2 years.
本文介绍了一种新型可植入式听力系统——直接声学耳蜗刺激器（DACS）。该系统基于动力驱动镫骨假体的原理，旨在治疗因晚期耳硬化症导致的重度混合性听力损失。它由一个可植入的电磁换能器和一个佩戴在植入耳后方外部的音频处理器组成，电磁换能器可将声能直接传输至内耳。该装置通过一种专门开发的耳后微手术方法进行植入。在去除镫骨后，将一个传统的镫骨假体连接到换能器上，并放置在卵圆窗处以实现与内耳外淋巴的直接声学耦合。为了恢复听骨链的自然声音传导，如同在传统镫骨切除术中一样，将第二个镫骨假体与第一个平行放置在卵圆窗内，并连接到患者自身的砧骨上。四名患者植入了研究性DACS装置。植入前，植入耳的听力阈值在78至101分贝之间（气导，纯音平均值，0.5 - 4千赫），在相同频率范围内气骨导差为33 - 44分贝。术后，所有患者在声场阈值、言语清晰度以及日常情况主观评估方面均有显著改善。植入两年后，使用DACS时，在75分贝安静环境下单音节词识别分数提高了45 - 100个百分点。此外，仅第二个镫骨假体就使听力阈值提高了14 - 28分贝（纯音平均值0.5 - 4千赫，DACS关闭）。未发生与装置相关的严重医疗并发症，所有患者已持续日常使用该装置超过两年。
