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Objectives/Hypothesis The differentiated character of changes in the mucous relief of the trachea as induced by air containing pollutants from the wastes of nickel-, mercury-, and cement-producing plants and by Candida albicans occurring in the waste disposal site of a large town are identified. The trachea was chosen because it is the entrance gate for the penetration of polluted air into the lungs. Changes on the trachea influence the character and extent of changes in lungs. Study Design Histological study with Viennese grey strain laboratory rabbits and rats caught directly on an investigated site. Methods We present new results of the functional morphology of the respiratory system as the results of scanning and transmission electron microscopy studies that can reveal character and range of damage of mucosal relief of trachea relevant to the functional dynamics of mucociliary clearance. Under physiological conditions this mechanism allows that only respirable dust particles enter the deep respiratory tract. Results In case of a damaged tracheal relief because of exposure to various aerosols, the functional morphology is changed, which aids in understanding the mechanisms damaging to mucociliary clearance induced by living in heavily polluted areas. Conclusion Understanding of these morphological changes on base of detailed electron microscopic findings sheds new light on elaborating novel diagnostic methods for clinical practice. [ABSTRACT FROM AUTHOR]

Objectives: We demonstrate that computer-assisted frameless stereotactic navigation with the ISG/ELEKTA Viewing Wand system in the petrous bone is routinely possible with sufficient application accuracy. Methods: High-resolution computed tomography imaging is done with a dedicated structure attached to the mouthpiece of the Vogele-Bale-Hohner (VBH) head holder, an integral part of our intraoperative patient fixation. The patient image registration can be reliably performed before surgery in an unsterile environment with the registration structure of the mouthpiece. For intraoperative navigation either the position-sensitive articulated arm or the optical three-dimensional digitizer of the ISG/ELEKTA system is used. Results: In the operations of the petrous bone performed so far, i.e., mastoidectomy, cholesteatoma surgery, and lateral skull base revision surgery, the clinical value of three-dimensional navigation was clearly demonstrated with an application accuracy, constant throughout surgery, mostly limited only by the resolution of the computed tomography. [ABSTRACT FROM AUTHOR]

We report the first intraoperative use of a microdebrider as a stereotactic three-dimensional (3D) navigation instrument in paranasal and frontobasal surgery. The microdebrider uses rotating blades and an integrated suction device for controlled removal of tissue under video-endoscopic view. The ISG Viewing Wand uses the patient's computed tomography/magnetic resonance (CT/MR) data and a 3D reconstruction thereof and a high-precision position-sensitive mechanical arm for intraoperative three-dimensional navigation. We have linked the microdebrider to the Viewing Wand to transform it into a continuously available intraoperative stereotactic localizing device. We discuss the problems related to this extension of the Viewing Wand and demonstrate the practical use in an exemplary polypectomy. [ABSTRACT FROM AUTHOR]

Frameless stereotactic procedures crucially depend on the firmness of immobilization. Once registered, shifting of the patient leads to inaccuracy, and the patient registration has to be realigned. To overcome the drawbacks of conventional invasive fixation for neurosurgery and the widely accepted fixation with surgical tape in ENT, the Vogele-Bale-Hohner (VBH) head holder has been developed. It permits rigid, noninvasive fixation of the head by using an individualized dental cast attached to the upper jaw by vacuum. Oral intubation is uncomplicated. In addition, a special registration device providing well defined reference points can be mounted to the mouthpiece. We report the first promising clinical applications of this device. [ABSTRACT FROM AUTHOR]

We report the intraoperative use of bent probes for 3-dimensional computer-assisted navigation in ENT surgery with the ISG Viewing Wand. Probe calibration is standardized and the new probes comply with the overall application accuracy of the navigation system. The bent probes permit an easy access to the remotest locations of the maxillary and the frontal sinus and are beneficial for application in paranasal sinus surgery. We present our clinical experiences with these probes. [ABSTRACT FROM AUTHOR]

Problem: Three-dimensional models are quite common now, but are still restricted to a 2-dimensional view by a screen or beamer. We use CAVE technology for education of complex anatomical findings and for surgical simulation.Methods: We create models by segmentation of datasets using the “3D-Slicer.” For the small structures in the temporal bone we used an experimental cone-beam Volume CT prototype that offers 160 micron isotropic resolutions. The CAVE is a Virtual Reality Center (VRC) which allows real-time visualization of interactive, complex graphical data in a walkable room. The graphical visualization is achieved by rear-panel beamers on 3 walls and a projection surface on the floor. Multiple users can interact in this virtual surrounding with different types of graphical data by rotating, zooming, or performing any programmable function.Results: Teaching pathologic findings or surgical planning in challenging cases are the most common fields of application. We use this technology for students’ and residents’ learning difficult anatomic findings. By simulating different pathways we can experience the changes of the anatomy or pathology, which is presented in its variations to the surgeons’ view.Conclusion: Using CAVE technology for medical imaging is the next step of 3D visualization. Most advantages are in the field of education because of the possibility for several dozen individuals to see 3D models simultaneously and to interact with real patients’ data (in other words, allowing a “hands-on effect”).Significance: By using virtual reality we presume to optimize the learning curve of students and especially residents, who are in the first training stages of acquiring the skill of surgery. Another possibility of training surgeons is to simulate the surgeons’ view through a microscope, which is harder because of the loss of landmarks. Walking around the model helps to train the “mental eye” and improves the surgical skills of young surgeons.Support: None reported. [Copyright &y& Elsevier]