Eisenring, ChristianChristianEisenringBurn, FeliceFeliceBurnBaumann, MichelleMichelleBaumannStieglitz, Lennart H.Lennart H.StieglitzKockro, Ralf A.Ralf A.KockroBeck, JürgenJürgenBeckRaabe, AndreasAndreasRaabeOertel, Markus F.Markus F.Oertel2024-10-282024-10-282020-03https://boris-portal.unibe.ch/handle/20.500.12422/184930BACKGROUND 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.enApp External ventricular drain Neuronavigation Smartphone Ventriculostomy600 - Technology::610 - Medicine & healtharticle10.7892/boris.1374273176197510.1007/s00701-019-04131-9