Tang Shan, Melvin Thuy-Anh N, Della Santina Charles C
Department of Otolaryngology, Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Acta Otolaryngol. 2009 May;129(5):481-6. doi: 10.1080/00016480802252243.
Implantation of vestibular prosthesis electrodes in chinchilla semicircular canal ampullae can be accomplished without significant loss of cochlear function; however, the risk of hearing loss with the current surgical technique is high.
To determine if it is possible to implant vestibular prosthesis electrodes into the labyrinth without damaging hearing, and to quantify the extent of hearing loss due to implantation.
The left semicircular canals of six chinchillas were implanted with three bipolar pairs of electrodes using a transmastoid approach. Right ears, which served as controls, were subjected to the same mastoid approach without fenestration and implantation. Auditory brainstem response hearing thresholds to free-field clicks and tone pips at 2, 4, 6, and 8 kHz were measured bilaterally 3-9 weeks after implantation. Hearing thresholds were compared between sides and against data from six normal chinchillas.
Four implanted ears suffered severe hearing loss, with thresholds ranging from 5 to 11 SD above the mean threshold of sham surgery control ears across all tested stimuli. Two implanted ears had preserved hearing, with thresholds remaining within 1 SD of the mean threshold of sham surgery control ears across nearly all stimulus frequencies.
将前庭假体电极植入龙猫半规管壶腹可在不显著丧失耳蜗功能的情况下完成；然而，当前手术技术导致听力损失的风险很高。
确定是否有可能在不损害听力的情况下将前庭假体电极植入内耳迷路，并量化植入导致的听力损失程度。
采用经乳突入路，为六只龙猫的左侧半规管植入三对双极电极。作为对照的右耳采用相同的乳突入路，但不进行开窗和植入操作。在植入后3 - 9周，双侧测量对自由场短声以及2、4、6和8千赫兹纯音短音的听觉脑干反应听力阈值。比较两侧的听力阈值，并与六只正常龙猫的数据进行对比。
四只植入电极的耳朵出现严重听力损失，在所有测试刺激下，其阈值比假手术对照耳的平均阈值高出5至11个标准差。两只植入电极的耳朵听力得以保留，在几乎所有刺激频率下，其阈值均保持在假手术对照耳平均阈值的1个标准差范围内。
