Tsukada Keita, Usami Shin-Ichi
Department of Otolaryngology, Shinshu University School of Medicine, Matsumoto, Japan.
Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto, Japan.
Front Neurol. 2021 Apr 27;12:656592. doi: 10.3389/fneur.2021.656592. eCollection 2021.
The development of less traumatic surgical techniques, such as the round window approach (RWA), as well as the use of flexible electrodes and post-operative steroid administration have enabled the preservation of residual hearing after cochlear implantation (CI) surgery. However, consideration must still be given to the complications that can accompany CI. One such potential complication is the impairment of vestibular function with resulting vertigo symptoms. The aim of our current study was to examine the changes in vestibular function after implantation in patients who received CI using less traumatic surgery, particularly the RWA technique. Sixty-six patients who received CI in our center were examined by caloric testing, cervical vestibular evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) before or after implantation, or both, to obtain data on semicircular canal, saccular and utricular function, respectively. Less traumatic CI surgery was performed by the use of the RWA and insertion of flexible electrodes such as MED-EL FLEX soft, FLEX 28, and FLEX 24 (Innsbruck, Austria). Caloric response and the asymmetry ratio of cVEMP and oVEMP were examined before and after implantation using less traumatic surgical techniques. Compared with before implantation, 93.9, 82.4, and 92.5% of the patients showed preserved vestibular function after implantation based on caloric testing, cVEMP and oVEMP results, respectively. We also examined the results for vestibular function by a comparison of the 66 patients using the RWA and flexible electrodes, and 17 patients who underwent cochleostomy and insertion of conventional or hard electrodes. We measured responses using caloric testing, cVEMP and oVEMP in patients after CI. There were no differences in the frequencies of abnormal caloric and oVEMP results in the implanted ears between the RWA and cochleostomy. On the other hand, the frequency of abnormal cVEMP responses in the implanted ears in the patients who received implantation by cochleostomy was significantly higher than that in the patients undergoing surgery using the RWA. Patients receiving CI using less traumatic surgical techniques such as RWA and flexible electrodes have reduced risk of damage to vestibular function.
创伤较小的手术技术的发展，如圆窗入路（RWA），以及柔性电极的使用和术后类固醇给药，使得人工耳蜗植入（CI）手术后能够保留残余听力。然而，仍必须考虑CI可能伴随的并发症。其中一种潜在并发症是前庭功能受损并导致眩晕症状。我们当前研究的目的是检查采用创伤较小的手术（特别是RWA技术）进行CI植入的患者术后前庭功能的变化。对在我们中心接受CI植入的66例患者在植入前或植入后或两者均进行了冷热试验、颈前庭诱发肌源性电位（cVEMP）和眼VEMP（oVEMP）检查，以分别获取关于半规管、球囊和椭圆囊功能的数据。采用RWA并插入诸如MED-EL FLEX soft、FLEX 28和FLEX 24（奥地利因斯布鲁克）等柔性电极进行创伤较小的CI手术。使用创伤较小的手术技术，在植入前后检查冷热反应以及cVEMP和oVEMP的不对称率。基于冷热试验、cVEMP和oVEMP结果，分别有93.9%、82.4%和92.5%的患者在植入后显示前庭功能得以保留。我们还通过比较66例采用RWA和柔性电极的患者以及17例接受蜗窗造口术并植入传统或硬电极的患者的前庭功能结果进行了研究。我们在CI植入后的患者中使用冷热试验、cVEMP和oVEMP测量反应。RWA组和蜗窗造口术组植入耳中冷热试验和oVEMP异常结果的频率没有差异。另一方面，接受蜗窗造口术植入的患者植入耳中cVEMP异常反应的频率显著高于采用RWA进行手术的患者。采用RWA和柔性电极等创伤较小的手术技术进行CI植入的患者，前庭功能受损的风险降低。
