Clark Graeme M, Clark Jonathan, Cardamone Tina, Clarke Maria, Nielsen Prue, Jones Rob, Arhatari Benedicta, Birbilis Nick, Curtain Roger, Xu Jin, Wagstaff Sheryl, Gibson Peter, O'Leary Stephen, Furness John
Cochlear Implants Int. 2014 Sep;15 Suppl 2:S1-15. doi: 10.1179/1754762814Y.0000000087. Epub 2014 Jun 10.
To analyse the temporal bones and implant of the first University of Melbourne's (UOM) patient (MC-1) to receive the multi-channel cochlear prosthesis.
The left cochlea was implanted with the prototype multi-channel cochlear prosthesis on 1 August 1978, and the Cochlear versions CI-22 and CI-24 on 22 June 1983 and 10 November 1998, respectively. MC-1 died in 2007.
Plain X-rays of the temporal bones showed that after the CI-22 had been explanted seven electrode bands remained in situ. Micro-CT scans also revealed a partially united fracture transecting the left implanted and right control cochleae. Histology indicated a total loss of the organ of Corti on both sides, and a tear of the left basilar membrane. In addition, there was a dense fibrous capsule with heterotopic bone surrounding one proximal band of the CI-22 array that restricted its removal. This pathology was associated with dark particulate material within macrophages, probably due to the release of platinum from the electrode bands. Scanning electron microscopy (SEM) showed possible corrosion of platinum and surface roughening. Three-dimensional reconstruction of the cochlear histology demonstrated the position of the electrode tracts (C1-22 and CI-24) in relation to the spiral ganglion, which showed 85-90% loss of ganglion cells.
This study confirms our first histopathological findings that our first free-fitting banded electrode array produced moderate trauma to the cochlea when inserted around the scala tympani of the basal turn. The difficulty in extraction was most likely due to one band being surrounded by an unusually large amount of fibrous tissue and bone, with an electrode band caught due to surface irregularities. Some surface corrosion and a small degree of platinum deposition in the tissue may also help explain the outcome for this long-term cochlear implantation.
分析墨尔本大学（UOM）首例接受多通道人工耳蜗植入患者（MC - 1）的颞骨及植入物情况。
1978年8月1日，患者左侧耳蜗植入了多通道人工耳蜗原型，1983年6月22日和1998年11月10日分别植入了Cochlear公司的CI - 22型和CI - 24型人工耳蜗。MC - 1于2007年去世。
颞骨的普通X线片显示，CI - 22型人工耳蜗取出后，仍有7条电极带留在原位。显微CT扫描还显示，一条部分愈合的骨折线横断左侧植入耳蜗和右侧对照耳蜗。组织学检查表明，两侧的柯蒂氏器均完全丧失，左侧基底膜撕裂。此外，CI - 22型电极阵列的一个近端带周围有致密的纤维囊及异位骨，限制了其取出。这种病理情况与巨噬细胞内的深色颗粒物质有关，可能是由于电极带释放出铂所致。扫描电子显微镜（SEM）显示铂可能存在腐蚀以及表面粗糙。耳蜗组织学的三维重建显示了电极通道（C1 - 22和CI - 24）相对于螺旋神经节的位置，螺旋神经节显示神经节细胞损失85 - 90%。
本研究证实了我们最初的组织病理学发现，即我们首个可自由适配的带状电极阵列在插入蜗底鼓阶周围时，对耳蜗产生了中度创伤。取出困难很可能是由于一条电极带被异常大量的纤维组织和骨包围，且一条电极带因表面不平整而被卡住。组织中的一些表面腐蚀和少量铂沉积也可能有助于解释此次长期人工耳蜗植入的结果。
