Cisneros J C, Brito R de, Martins G S de, Candido N, Ferraz R, Bento R
a Hospital das Clínicas - University of São Paulo , São Paulo , Brazil.
b National Institute of Rehabilitation , Mexico City , Mexico.
Cochlear Implants Int. 2017 Mar;18(2):106-115. doi: 10.1080/14670100.2016.1265190. Epub 2016 Dec 23.
The microgrinding technique is used to study cochlear implant electrode positioning and cochlear trauma. It may be argued that this technique might cause damage to inner cochlear structures even without a cochlear implant insertion and thus it should not be recommended. Most papers do not explain how microgrinding is performed, referring to older papers for its description. Properly describing the technique and re-evaluating its safety may reassure researchers of their findings when studying trauma after cochlear implant insertion.
To accurately describe the microgrinding technique and re-evaluate its safety to assess intracochlear trauma by studying non-implanted temporal bones.
Four fresh temporal bones were removed before 24 hours postmortem and frozen at -20°C. Two were prepared for microgrinding before 24 hours of freezing and the others after 6 months. A descriptive analysis of the microscopic anatomy was performed, as well as a comparison between the bones processed within 24 hours of freezing and the bones frozen for 6 months.
A total of 80 surfaces was evaluated. Preservation of even the most delicate intracochlear and vestibular structures was observed, such as the crista ampullaris, Reissner's and basilar membranes, permitting an adequate micro-anatomical study. Artifacts were rare and did not interfere with the analysis. Bones studied before 24 hours postmortem exhibited better quality than those frozen for 6 months.
The microgrinding technique accurately preserves the inner ear's membranous microscopic anatomy and thus it is useful to study cochlear implant electrode positioning and trauma inside the cochlea. Studies that aim to evaluate inner ear microanatomy should be performed with fresh bones or bones frozen for less than 24 hours since they exhibit a better micro-anatomical quality.
微磨技术用于研究人工耳蜗电极定位和耳蜗创伤。可能有人认为，即使不植入人工耳蜗，该技术也可能对耳蜗内部结构造成损伤，因此不应推荐使用。大多数论文没有解释微磨是如何进行的，而是参考旧论文来描述它。正确描述该技术并重新评估其安全性，可能会让研究人工耳蜗植入后创伤的研究人员对其研究结果更有信心。
准确描述微磨技术并重新评估其安全性，通过研究未植入人工耳蜗的颞骨来评估耳蜗内创伤。
在死后24小时内取出4块新鲜颞骨，在-20°C下冷冻。其中2块在冷冻24小时前准备进行微磨，另外2块在6个月后准备。对微观解剖结构进行描述性分析，并比较冷冻24小时内处理的骨头和冷冻6个月的骨头。
共评估了80个表面。观察到即使是最精细的耳蜗内和前庭结构，如壶腹嵴、Reissner膜和基底膜，也得以保留，从而能够进行充分的微观解剖学研究。伪像很少，不影响分析。死后24小时内研究的骨头比冷冻6个月的骨头质量更好。
微磨技术能准确保留内耳的膜性微观解剖结构，因此对于研究人工耳蜗电极定位和耳蜗内创伤很有用。旨在评估内耳微观解剖结构的研究应使用新鲜骨头或冷冻时间少于24小时的骨头，因为它们的微观解剖质量更好。
