0000000000033847
AUTHOR
U. Ecke
Elektrophysiologische Untersuchung zum Einsatz von Streptolysin O und Natrium-Hyaluronat zur Permeabilitätsmodulation der Membran des runden Fensters beim Meerschweinchen
Background: The round window membrane (RWM) acts like a barrier for topically applied substances into the middle ear preventing diffusion into the perilymphatic fluid compartment. Material and Method: In an animal model, modulation of the permeability of the RWM was attempted using Streptolysin-O (SLO) in various concentrations and sodium hyaluronate. Thereafter, the effect of intratympanically applied Lidocain 2% on hearing threshold measured by auditory brainstem response was tested for Lidocain 2 % and Lidocain 2 % in combination with SLO or sodium hyaluronate. Results: The results show that both, SLO and sodium hyaluronate, influence the effect of Lidocain 2 % on hearing thresholds as a…
Der Einsatz eines optischen Navigationssystem in der Nasennebenh�hlenchirurgie
Hintergrund. Fur die moderne Nasennebenhohlenchirurgie stehen heute verschiedene CAS-Systeme zur Verfugung.Das Vector-Vision-Compact®-System stellt erstmals ein speziell fur Nasennebenhohleneingriffe konzipiertes optisches Gerat dar.Seine Praktikabilitat und Zuverlassigkeit wurde in der Nasennebenhohlenchirurgie uberpruft. Patienten und Methode. Das System wurde bei 60 Patienten mit polyposer Pansinusitis verwendet.Die Bestimmung der Systemgenauigkeit erfolgte visuell und wurde mit etablierten Systemen verglichen.Fehlerquellen sowie systembedingte Komplikationen wurden uberpruft. Ergebnisse. Die Systemgenauigkeit betrug 1,9 mm und war anderen Navigationssystemen gleichwertig. In 83,3% aller…
Selective Chemical Vestibulectomy
In an attempt to destroy the peripheral vestibular labyrinth selectively in patients suffering from intractable vertigo as a result of end-stage Meniere’s disease, 25 patients underwent selective chem
Fehlerquellen der Navigation in der lateralen Sch�delbasischirurgie
Die Identifikation moglicher Storfaktoren navigationsunterstutzter Eingriffe an der lateralen Schadelbasis ermoglichen dem Anwender die Vermeidung und Behebung dieser Fehler. Anhand unserer Erfahrungen von 85 navigationsunterstutzten Eingriffen im Bereich der lateralen Schadelbasis werden Fehler der Hard- und Software, der Bildgebung und des -transfers, der Patientenregistrierung, durch den Anwender und solche strategischer Art analysiert. Bei optischen CAS-Systemen fuhrt eine Blockade des Sichtfelds der Kameras zu Funktionsbeschrankungen, wahrend elektromagnetische Systeme durch ferromagnetisch aktive Materialien beeinflusst werden konnen. Die bisherigen Verfahren der Patientenregistrierun…
Possible roles of nitric oxide in the physiology and pathophysiology of the guinea pig cochlea.
Two nitric oxide synthase isoforms (NOS-I and NOS-III) are present in the mammalian cochlea, and many regulatory functions of the inner ear could be mediated by NO. In this study, cochlear potentials and immunohistochemical measures were analyzed by changing the concentration of NO in the guinea pig during intracochlear and intravenous application of an NOS inhibitor and an NO donor. In anesthetized guinea pigs the NOS inhibitor NG-nitro-L-arginine-methylester (L-NAME) was applied by intracochlear perfusion or intravenously. The cochlear potentials and blood pressure were measured during and after the application. Cochleae were removed and prepared for morphological and immunohistochemical …
Real-time simulation of tissue deformation for the nasal endoscopy simulator (NES).
Endonasal sinus surgery requires a great amount of training before it can be adequately performed. The complicated anatomy involved, the proximity of relevant structures, and the variability of the anatomy due to inborn or iatrogenic variations make several complications possible. Today, cadaver dissections are the "gold standard" for surgical training. To overcome the drawbacks of traditional training methods, the Fraunhofer Institute for Computer Graphics is currently developing a highly interactive medical simulation system for nasal endoscopy and endonasal sinus surgery, in cooperation with the Mainz University Hospital. For the simulation of a rhinoscopic procedure, not only are the re…
Intraoperative Navigation in der Chirurgie der Nasennebenhöhlen und der vorderen Schädelbasis
Hintergrund und Fragestellung. Beim Einsatz der computerassistierten Chirurgie im Bereich der Nasennebenhohlen und vorderen Schadelbasis sind einige Fehlerquellen zu beachten, die durch physikalische Gesetze, den technischen Entwicklungs- und individuellen Kenntnisstand des Anwenders bedingt sind. Patienten/Methodik. Anhand unserer Erfahrungen von 436 navigationsunterstutzten Eingriffen werden Hard- und Softwarefehler, Fehler der Bildgebung und des -transfers, Fehler der Patientenregistrierung, Anwenderfehler und strategische Fehler analysiert. Ergebnisse. Bei optischen CAS-Systemen fuhrt die Blockade des Sichtfeldes der Kamera zu Funktionseinschrankungen, wahrend elektromagnetische Systeme…
A Passive-Marker-Based Optical System for Computer-Aided Surgery in Otorhinolaryngology: Development and First Clinical Experiences
Objectives: To develop a new type of optical computer-aided surgery (CAS) device that overcomes some of the restrictions of common systems and to examine its accuracy and usability under laboratory and intraoperative conditions. Study Design: Prospective study using laboratory experiments and intraoperative data collection. Methods: An optical CAS system applying passive optical markers for coordinate determination was developed. Laboratory accuracy measurements were obtained on a Plexiglas model with known coordinates of fiducial markers, before and after predefined table movements. Intraoperative accuracy measurements were recorded from 24 patients undergoing endonasal surgery of the para…
Yamik Sinus Catheter in the Topical Treatment of Patients with Acute Rhinosinusitis after Previous Sinus Surgery
Background The Yamik sinus catheter was designed as a new device for the topical treatment of rhinosinusitis. It creates intermittent positive and negative intranasal pressure after sealing the ipsilateral nostril and choana with two inflatable cuffs. Affecting the nasal cavity and all paranasal sinuses of one side at a time, it is used to evacuate mucous and secretions as well as and to introduce antiseptic, antibacterial, or antifungal solutions. Methods This study was designed to evaluate the effectiveness of the Yamik catheter in cases of acute purulent rhinosinusitis in patients who previously underwent endonasal sinus surgery for chronic rhinosinusitis. Twenty patients were treated at…