King E B, Hartsock J J, O'Leary S J, Salt A N
Department Otolaryngology, University of Melbourne, Melbourne, Vic., Australia.
Audiol Neurootol. 2013;18(5):307-16. doi: 10.1159/000353534. Epub 2013 Sep 5.
Locally applied drugs can protect residual hearing following cochlear implantation. The influence of cochlear implantation on drug levels in the scala tympani (ST) after round window application was investigated in guinea pigs using the marker trimethylphenylammonium (TMPA) measured in real time with TMPA-selective microelectrodes. TMPA concentration in the upper basal turn of the ST rapidly increased during implantation and then declined due to cerebrospinal fluid entering the ST at the cochlear aqueduct and exiting at the cochleostomy. The TMPA increase was found to be caused by the cochleostomy drilling if the burr tip partially entered the ST. TMPA distribution in the second turn was less affected by implantation procedures. These findings show that basal turn drug levels may be changed during implantation and the changes may need to be considered in the interpretation of therapeutic effects of drugs in conjunction with implantation.
局部应用药物可保护人工耳蜗植入后的残余听力。在豚鼠中，使用TMPA选择性微电极实时测量标记物三甲基苯基铵（TMPA），研究了圆窗给药后人工耳蜗植入对鼓阶（ST）中药物水平的影响。植入过程中，ST上基底转中的TMPA浓度迅速升高，随后由于脑脊液经蜗水管进入ST并从蜗窗流出而下降。如果钻头尖端部分进入ST，发现TMPA升高是由蜗窗钻孔引起的。植入程序对第二转中TMPA分布的影响较小。这些发现表明，植入过程中基底转的药物水平可能会发生变化，在解释药物与植入联合治疗效果时可能需要考虑这些变化。
