Magnetic Control of the Glottic Opening in an Ex Vivo Sheep Larynx Model: A Preliminary Study.

OBJECTIVE/HYPOTHESIS: So far, a number of techniques have been described for the treatment of bilateral vocal fold paralysis. These techniques were reported to be successful in maintaining an adequate airway but also found to be associated with an increased risk of aspiration, dysphonia, and granulation tissue formation at the operation site. We aimed to investigate the effectiveness of a novel mucosa-sparing technique based on the generation of a magnetic field within the larynx for the tailored lateralization of the ipsilateral vocal fold. STUDY DESIGN: This is an ex vivo experimental study. METHODS: Twenty sheep larynges that were procured from the local slaughterhouse were used as a model. For each specimen, two neodymium (Nd) disc magnets with marked poles were used to create a unilateral attractive magnetic force at the glottic level. Following insertion of the magnets, the level of vocal fold lateralization was assessed under an operating microscope. The results were analyzed for their statistical significance. RESULTS: Before the procedure, the mean value of the glottic openings of all the specimens was 4.985 mm. The postprocedure mean value was 5.640 mm. The mean amount of increase in the glottic openings after the procedure was 0.655 mm. This change was found to be statistically significant (P < 0.05). CONCLUSIONS: A statistically significant increase in the cross-sectional area of the glottic region could be achieved. The mucosal integrity of the laryngeal airway was also preserved. The idea of "magnetic control of the glottic airway" is a novel concept but seems to be a promising option.

In vitro analysis of a novel controlled release system designed for intratympanic administration of N-acetylcysteine: a preliminary report.

The aim of this in-vitro experimental study was to design a novel drug delivery system that may permit controlled release of N-acetylcysteine (NAC) following intratympanic administration. The system was composed of two different solutions that attained a hydrogel form within seconds after getting into contact with each other. The authors performed swelling, pH and temperature tests and analysis of controlled release of NAC from this novel controlled release system. For the structure and porosity analysis of the hydrogel, an environmental scanning electron microscope (SEM) was used. The diameter of designed hydrogel showed an increase when pH was increased. In addition, in comparison to acidic values, the pore diameter of the hydrogel increased significantly especially in physiological level. The increase in the pore diameter was also directly proportional to the increase in temperature. Spectrophotometric analysis showed that the amount of NAC released into the medium was statistically significant (p=0.038, t=-2.18, 95% CI; DF: 27). SEM analysis of the samples revealed a smooth surface topography and numerous porous structures. The authors are of the opinion that the designed hydrogel may be used as an alternative method for intratympanic delivery of NAC for otoprotective purposes. The disadvantages of intratympanic injection of the drug in its liquid form, including leakage through eustachian tube, restraining the patient in an uncomfortable position, necessity for repetitive injections and dose dependent inflammation of the middle ear epithelium, may also be avoided. Further in vivo studies should be conducted to assess its tolerability and effectivity.