Pediatric Percutaneous Cochlear Implantation Clinical Validation & Implementation

描述（由申请人提供）：目前，人工耳蜗（CI）手术需要进入内耳，特别是耳蜗，其中使用电极阵列来刺激听神经，使聋人能够听到声音。全球已经有超过12万个ci。预测表明，多达75万名严重听力损失的美国人可能受益于CI (Mohr, Feldman, Dunbar et al., 2000)，其中许多是儿童。在我们正在进行的美国国立卫生研究院资助的成人项目（R01 DC008408）中，我们已经证明了经皮人工耳蜗植入术（PCI）的可行性。PCI将CI手术减少到从侧颅底到耳蜗的一次钻孔。通过图像引导技术规划和执行钻孔路径，以避免重要的邻近解剖，击中目标-耳蜗的鼓膜。在临床试验中，我们已经在15名成年患者身上验证了这项技术，统计预测表明99.9%的人避免了重要解剖，特别是面神经。在附件中，我们建议将这项技术应用于儿科人群。要做到这一点，就必须修改我们的技术。我们目前的成人技巧包括以下六个步骤：(i)在门诊局部麻醉下，在耳朵周围放置三个骨植入基准标记/锚点，（ii）获得临床适用的CT扫描，（iii）使用CT扫描规划从颅骨表面到耳蜗基底转的手术轨迹，避免重要解剖，（iv）构建微立体定向框架以约束钻头沿着计划的轨迹通过（对于成人研究，框架构建需要48小时），(v)将框架固定在植骨锚上，以及（vi）使用框架确认钻孔轨迹。由于儿童和成人的解剖结构不同，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地图集，这将使我们能够以自动化的方式执行步骤（iii），就像我们目前使用单一地图集对成人所做的那样。由于联邦指南禁止在没有获益前景的情况下对儿童进行风险大于最小的临床研究，因此我们对步骤（ii）和（iv）进行了实质性修改，使CT扫描的获取和微立体定向框架的设计和构建与传统CI手术同时进行，从而将风险降低到指南规定的可接受水平。为了做到这一点，我们做了大量的工作，将术中CT扫描仪纳入我们的方案，并设计、开发和测试了一种新的微立体定向框架，它可以在30分钟内设计和构建，远远低于我们回顾的2256例手术中最短的手术时间。我们还招募了另外两个备受尊敬的CI项目参与研究——男孩镇（奥马哈，东北）和世界上最繁忙的CI中心——汉诺威医院（德国汉诺威），我们与他们有长期合作关系。我们希望这项技术，即经皮人工耳蜗植入术，能使人工耳蜗手术更快、更便宜、更容易，让更多的儿童受益于人工耳蜗的听力康复。

DESCRIPTION (provided by applicant): 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. PUBLIC HEALTH RELEVANCE: In the United States about 20,000 deaf children have benefitted from cochlear implantation, a 2+ hour surgery that involves removal of a portion of the bone behind the external ear to reach the inner ear, the cochlea, and place a wire which stimulates the cochlea allowing hearing. Using image guided surgical techniques-similar to GPS technology used to provide geographic directions-we have shown that a much less invasive surgical approach is possible by tracking and controlling the path of a drill such that the cochlea may be reached by a single drill-we call this technique Percutaneous Cochlear Implantation (PCI) and have demonstrated it in adult patients. We now propose to test and perform PCI in children with our efforts focused on the differences between adults and children (for example, (i) anatomy and (ii) federal regulations governing research) with the proposed benefits of PCI including decreased operative time, decreased surgical cost, standardized surgery, and possibly even improved hearing outcomes.