BACKGROUND Currently, the trajectory for insertion of an external ventricular drain (EVD) is mainly determined using anatomical landmarks. However, non-assisted implantations frequently require multiple attempts and are associated with EVD malpositioning and complications. The authors evaluated the feasibility and accuracy of a novel smartphone-guided, angle-adjusted technique for assisted implantations of an EVD (sEVD) in both a human artificial head model and a cadaveric head. METHODS After computed tomography (CT), optimal insertion angles and lengths of intracranial trajectories of the EVDs were determined. A smartphone was calibrated to the mid-cranial sagittal line. Twenty EVDs were placed using both the premeasured data and smartphone-adjusted insertion angles, targeting the center of the ipsilateral ventricular frontal horn. The EVD positions were verified with post-interventional CT. RESULTS All 20 sEVDs (head model, 8/20; cadaveric head, 12/20) showed accurate placement in the ipsilateral ventricle. The sEVD tip locations showed a mean target deviation of 1.73° corresponding to 12 mm in the plastic head model, and 3.45° corresponding to 33 mm in the cadaveric head. The mean duration of preoperative measurements on CT data was 3 min, whereas sterile packing, smartphone calibration, drilling, and implantation required 9 min on average. CONCLUSIONS By implementation of an innovative navigation technique, a conventional smartphone was used as a protractor for the insertion of EVDs. Our ex vivo data suggest that smartphone-guided EVD placement offers a precise, rapidly applicable, and patient-individualized freehand technique based on a standard procedure with a simple, cheap, and widely available multifunctional device.

中文翻译：

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sEVD-智能手机导航的外部心室引流管位置。

背景技术当前，主要使用解剖学界标来确定用于插入外部心室引流（EVD）的轨迹。但是，非辅助植入经常需要进行多次尝试，并伴有EVD错位和并发症。作者评估了一种新型的智能手机引导的角度调整技术在人工头模型和尸体头模型中辅助植入EVD（sEVD）的可行性和准确性。方法计算机断层扫描（CT）后，确定EVD的最佳插入角度和颅内轨迹长度。将智能手机校准至颅中矢状线。使用预先测量的数据和通过智能手机调整的插入角度放置20个EVD，以同侧心室额角的中心为目标。EVD位置已通过介入CT检查。结果所有20个sEVD（头部模型，8/20；尸体头部，12/20）均显示在同侧心室中。sEVD尖端位置在塑料头模型中显示的平均目标偏差为1.73°（对应于12毫米），在尸体头模型中为3.45°（对应于33毫米）。CT数据的术前测量平均持续时间为3分钟，而无菌包装，智能手机校准，钻孔和植入平均需要9分钟。结论通过实施创新的导航技术，传统的智能手机被用作量角器以插入EVD。我们的体外数据表明，智能手机引导的EVD放置可提供精确，快速适用的，