Pediatric Percutaneous Cochlear Implantation Clinical Validation & Implementation

项目摘要/摘要：目前需要接触到内耳，特别是耳蜗骨 植入(CI)手术，其中使用电极阵列来刺激听神经，并允许聋人 去听。全球已放置了超过12万个CI。预测表明，多达75万人 严重听力损失的美国人可能受益于CI(Mohr，Feldman，Dunbar等人，2000)，其中许多人 都是孩子。在我们正在进行的NIH资助的成人项目(R01 DC008408)中，我们已经证明了可行性 经皮人工耳蜗植入术(PCI)。经皮冠状动脉介入术将CI手术减少为从侧方钻进一次 从头骨底部到耳蜗骨。通过图像引导技术规划和执行演练路径，避免了 重要的邻近解剖结构并击中目标--耳蜗鼓阶。在临床试验中，我们已经验证了 这项技术在15名成年患者身上进行，统计数据显示99.9%的人避免了生命解剖， 尤其是面部神经。在附上的意见书中，我们建议将这项技术转化为儿科 人口。要做到这一点，有必要对我们的技术进行修改。我们目前的成人技术包括 以下六个步骤：(I)在耳部周围放置三个植入骨的基准标记/锚 门诊环境中的局部麻醉，(Ii)获得临床适用的CT扫描，(Iii)使用CT扫描 计划从头骨表面到耳蜗基底部的手术轨迹，避免重要的解剖， (Iv)建造一个微立体定向框架，以限制钻头沿计划的轨迹通过(成人 研究，框架建造需要48小时)，(V)将框架固定到植入骨的锚上，以及(Vi) 利用该框架来确认钻探轨迹。由于儿童和成人在解剖学上的不同，我们建议 通过使用儿童CT扫描的大型数据库来修改我们的技术，以产生年龄分层的解剖学数据 地图集将允许我们以自动方式执行第(Iii)步，就像我们目前为成年人所做的那样 一本单独的地图集。因为联邦指南禁止对风险超过最低限度的儿童进行临床研究 在没有使儿童受益的前景的情况下，我们对步骤(2)和(4)进行了重大修改，使这两个步骤都 CT扫描的采集以及微立体定向框架的设计和构造 与传统的CI手术同时进行，从而将风险降低到指南下可接受的水平。 为了做到这一点，我们已经做了大量的工作，将术中CT扫描仪纳入我们的方案中，并 设计、开发和测试了一种新型的微立体定向框架，可以在30分钟内设计和建造 几分钟--远低于我们回顾的2,256例手术的最短手术时间。我们已经招募了两名 参与研究的其他备受尊敬的CI项目-男孩镇(内华达州奥马哈)和最繁忙的CI 世界中心，汉诺威医院(德国汉诺威)，我们与之保持着密切联系 协作。我们希望这项技术--经皮人工耳蜗术--将使CI手术 更快、更便宜、更容易执行，使更多的儿童受益于CI的听力康复。

Project Summary/Abstract: Access to the inner ear, specifically the cochlea, is currently required for cochlear implant (CI) surgery, in which an electrode array is used to stimulate the auditory nerve and allow deaf people to hear. More than 120,000 CIs have been placed worldwide. Projections indicate that up to 750,000 Americans with severe hearing loss may benefit from CI (Mohr, Feldman, Dunbar et al., 2000) many of whom are children. In our ongoing, NIH-funded adult project (R01 DC008408), we have demonstrated the feasibility of percutaneous cochlear implantation (PCI). PCI reduces CI surgery to a single pass of a drill from the lateral skull base to the cochlea. The drill path is planned and executed via image-guided technology so as to avoid vital adjacent anatomy and hit the target-the scala tympani of the cochlea. In clinical trials we have validated the technique on 15 adult patients with statistical projections indicating 99.9% avoidance of vital anatomy, specifically the facial nerve. In the attached submission, we propose to translate this technology to the pediatric population. To do this, modifications to our technique are necessary. Our current adult technique consists of the following six steps: (i) placing three bone-implanted fiducial markers/anchors surrounding the ear under local anesthesia in an out-patient setting, (ii) obtaining a clinically applicable CT scan, (iii) using the CT scan to plan a surgical trajectory from the surface of the skull to the basal turn of the cochlea avoiding vital anatomy, (iv) constructing a microstereotactic frame to constrain a drill to pass along the planned trajectory (for the adult study, frame construction requires 48 hours), (v) affixing the frame to the bone-implanted anchors, and (vi) employing the frame to confirm the drill trajectory. Because children and adults differ anatomically, we propose to modify our technique by using a large database of pediatric CT scans to produce age-stratified anatomical atlases that will allow us to perform step (iii) in an automated fashion, as we are currently doing for adults with a single atlas. Because federal guidelines prohibit clinical studies on children entailing greater than minimal risk without the prospect of benefit for children, we have substantially modified steps (ii) and (iv) such that both the acquisition of the CT scan and the design and construction of the microstereotactic frame occur simultaneously with traditional CI surgery, thus reducing the risk to an acceptable level under the guidelines. To do this, we have done extensive work incorporating intraoperative CT scanner into our protocols and designed, developed, and tested a novel microstereotactic frame which can be designed and constructed in 30 minutes-well below the shortest surgical time in our review of 2,256 surgeries. We have recruited two additional well-respected CI programs to participate in the study-Boys Town (Omaha, NE) and the busiest CI center in the world, Medical Hospital of Hannover (Hannover, Germany) with whom we have a standing collaboration. Our hope is that this technique, percutaneous cochlear implantation, will make CI surgery quicker, cheaper, and easier to perform, allowing more children to benefit from aural rehabilitation with CIs.