Spiers Kathryn, Cardamone Tina, Furness John B, Clark Jonathan C M, Patrick James F, Clark Graeme M
a The Australian Synchrotron , Melbourne , Australia.
b Department of Anatomy and Neuroscience , University of Melbourne , Australia.
Cochlear Implants Int. 2016 May;17(3):129-31. doi: 10.1080/14670100.2016.1157943. Epub 2016 Mar 16.
The aim of this study was to analyse the tissue surrounding the University of Melbourne's (UOMs) multi-channel cochlear implant electrode array and cochlear limited replacements, after long-term implantations. In particular, it aimed to identify the particulate material in the fibrous tissue capsule of the arrays implanted in 1978, 1983, and 1998, by using the Australian Synchrotron for X-ray fluorescence microscopy (XFM) to reveal the characteristic spectrum of metal, in particular platinum. This also helped to determine its format and chemical state. Tissue was retrieved following the recipient's death in 2007.
Tissue was fixed and sections taken across the UOM and Cochlear Corporation (CI-22 and CI-24) electrode tracks. These were stained with Masson's trichrome. The Australian Synchrotron enabled XFM to accurately identify platinum from its characteristic fluorescence spectrum.
There was a fibrous tissue capsule (about 100-µm thick) and small regions of calcification around the UOM and CI-22 arrays, but a thinner capsule (40-60-µm thick) around CI-24, and a greater degree of calcification. Dark particulate matter was observed within macrophages and especially in fibrous tissue in proximity to the UOM and CI-22 arrays. This was identified as platinum using X-ray fluorescence. There was also diffusion of platinum into the tissue surrounding the UOM and CI-22 electrodes and fine particles had penetrated the spiral ligament.
The larger particulate matter in the tissue around the UOM and CI-22 arrays suggested that it had flaked off in the manufacturing of the UOM electrodes. The more diffuse spread of platinum in the tissue around the UOM and CI-22 electrodes was likely due to electrolysis, probably from charge imbalance with the bipolar pulses from the UOM implant. This did not occur with the Cochlear CI-24 device. Furthermore, the widespread fine particles of platinum could have also been due to corrosion, especially from the UOM electrodes.
本研究旨在分析墨尔本大学（UOM）多通道人工耳蜗电极阵列及人工耳蜗有限置换物在长期植入后的周围组织。具体而言，其目的是通过利用澳大利亚同步加速器进行X射线荧光显微镜检查（XFM），以识别1978年、1983年和1998年植入的阵列纤维组织包膜中的颗粒物质，从而揭示金属尤其是铂的特征光谱。这也有助于确定其形态和化学状态。组织于2007年受赠者死亡后取出。
组织经固定后，沿UOM和科利耳公司（CI - 22和CI - 24）电极轨迹切片。这些切片用马松三色染色法染色。澳大利亚同步加速器使XFM能够根据铂的特征荧光光谱准确识别铂。
UOM和CI - 22阵列周围有一层纤维组织包膜（约100微米厚）以及小面积钙化区域，但CI - 24周围的包膜较薄（40 - 60微米厚），且钙化程度更高。在巨噬细胞内尤其是靠近UOM和CI - 22阵列的纤维组织中观察到深色颗粒物质。通过X射线荧光鉴定其为铂。铂也扩散到了UOM和CI - 22电极周围的组织中，并且细颗粒已穿透螺旋韧带。
UOM和CI - 22阵列周围组织中较大的颗粒物质表明其在UOM电极制造过程中已剥落。UOM和CI - 22电极周围组织中铂的扩散更为广泛，这可能是由于电解，可能源于与UOM植入物双极脉冲的电荷不平衡。科利耳CI - 24装置未出现这种情况。此外，广泛存在的铂细颗粒也可能是由于腐蚀，尤其是UOM电极的腐蚀。
