Knox Glenn W, Reitan Harlan
Northeast Florida Ear Research Institute, University of Florida, 3663 Crown Point Court, Jacksonville, FL 32257, U.S.A.
Laryngoscope. 2005 Aug;115(8):1340-6. doi: 10.1097/01.mlg.0000172274.73365.11.
The aim of this study was to determine the efficacy of a shape-memory alloy, Nitinol, as a component of an improved stapes prosthesis.
Prospective laboratory and clinical study to develop a Nitinol stapes prosthesis.
Various diameters of Nitinol wire and temperature transition variants were analyzed with regard to ease of deformation, response to heating, and strength. The size and geometry of the closed hook was determined by measurement of 50 incus cadaver bones. Several heat sources for activating the shape memory were evaluated, including electrocautery, lasers, and warm water. Trial surgeries were then performed on human temporal bones in the laboratory. The closure characteristics of the Nitinol loop were studied. Magnetic resonance imaging (MRI) testing at 1.5 Tesla was performed to determine safety during MRI studies. Preliminary human subject trials were then instituted.
In all cases, a low heat condition was ample to activate the shape memory characteristics of the hook and return it to a closed position after it had been opened. Laser power was generally set well below the power needed for removing bone. The Nitinol loop closed snugly around the incus with application to the top of the hook with a low temperature laser setting. Almost any heat source was effective. MRI testing at 1.5 Tesla showed no movement of the prosthesis. Preliminary results in human subjects showed excellent air-bone closure. The Nitinol loop holds uniform contact around the incus.
The Nitinol piston greatly simplifies the stapedectomy procedure by taking the need for a hand operated instrument out of the surgeon's hands. Because of the nature of the Nitinol wire, it can never over-crimp. All these characteristics make the prosthesis advantageous for otosclerosis surgery.
本研究旨在确定形状记忆合金镍钛诺作为改良镫骨假体组件的疗效。
开发镍钛诺镫骨假体的前瞻性实验室和临床研究。
分析了各种直径的镍钛诺丝和温度转变变体在变形难易程度、对加热的反应及强度方面的情况。通过测量50块砧骨尸体骨骼来确定闭合钩的尺寸和几何形状。评估了几种用于激活形状记忆的热源，包括电灼、激光和温水。然后在实验室对人类颞骨进行试验性手术。研究了镍钛诺环的闭合特性。进行了1.5特斯拉的磁共振成像（MRI）测试以确定MRI研究期间的安全性。随后开展了初步人体试验。
在所有情况下，低热条件足以激活钩的形状记忆特性，并使其在打开后恢复到闭合位置。激光功率通常设定得远低于去除骨质所需的功率。在低温激光设置下，将镍钛诺环应用于钩的顶部时，它能紧密地围绕砧骨闭合。几乎任何热源都有效。1.5特斯拉的MRI测试显示假体无移动。人体试验的初步结果显示气骨导差闭合效果极佳。镍钛诺环在砧骨周围保持均匀接触。
镍钛诺活塞将手动器械从外科医生手中移除，极大地简化了镫骨切除术。由于镍钛诺丝的特性，它永远不会过度卷曲。所有这些特性使该假体在耳硬化症手术中具有优势。
