Summary Objectives/hypothesisTo study the hyaluronan occurrence in human vocal folds, with special regards to gender and smoking and to discuss the implications of findings. Study DesignThis is a descriptive/morphologic study. MethodsSixteen cadaveric vocal folds from eight individuals between 58 and 90 years old (six women and two men) were removed and studied morphologically. Three of the individuals had been cigarette smokers.A direct method for hyaluronan histochemistry using a hyaluronan-binding protein probe (HABP) was used to visualize the polysaccharide. Five examiners performed an analysis of the intensities of hyaluronan staining, independently. ResultsWe observed intense hyaluronan staining of the vocal folds of which those from women stained considerably stronger than those from men. Stratified squamous epithelium stained for hyaluronan in all sections, whereas respiratory epithelium only stained weakly or not at all. The highest accumulation of hyaluronan occurred subepithelially in the lamina propria, corresponding to Reinke's space. It was observed that vocal folds from smokers were more intensively stained than those from nonsmokers. 2 ConclusionsHyaluronan is found in all layers of the human vocal fold. Contradictory to earlier studies, hyaluronan was visualized in squamous epithelium, where it may function as an impact protector. The occurrence of hyaluronan in smokers may have implications in the development of vocal fold inflammation and tumor initiation as hyaluronan is an important molecule in these processes.

The HEARO cochlear implantation surgery aims to replace the conventional wide mastoidectomy approach with a minimally invasive direct cochlear access. The main advantage of the HEARO access would be that the trajectory accommodates the optimal and individualized insertion parameters such as type of cochlear access and trajectory angles into the cochlea. To investigate the quality of electrode insertion with the HEARO procedure, the insertion process was inspected under fluoroscopy in 16 human cadaver temporal bones. Prior to the insertion, the robotic middle and inner ear access were performed through the HEARO procedures. The status of the insertion was analyzed on the post-operative image with Siemens Artis Pheno (Siemens AG, Munich, Germany). The completion of the full HEARO procedure, including the robotic inner ear access and fluoroscopy electrode insertion, was possible in all 16 cases. It was possible to insert the electrode in all 16 cases through the drilled tunnel. However, one case in which the full cochlea was not visible on the post-operative image for analysis was excluded. The post-operative analysis of the electrode insertion showed an average insertion angle of 507°, which is equivalent to 1.4 turns of the cochlea, and minimal and maximal insertion angles were recorded as 373° (1 cochlear turn) and 645° (1.8 cochlear turn), respectively. The fluoroscopy inspection indicated no sign of complications during the insertion.

Øre-nese-halsavdelingen Haukeland universitetssjukehus og Klinisk institu 1 Universitetet i Bergen Han har bidra med idé, revisjon av manus og godkjenning av innsendte versjon av manus. Frederik Kragerud Goplen er ph.d., overlege og førsteamanuensis II. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter.Øre-nese-halsavdelingen Haukeland universitetssjukehus Hun har bidra med idé, revisjon av manus og godkjenning av innsendte versjon av manus. Jeane e Hess-Erga er overlege og seksjonsleder. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter.Øre-nese-halsavdelingen Oslo universitetssykehus, Rikshospitalet Han har bidra med idé, revisjon av manus og godkjenning av innsendte versjon av manus. Leif Runar Opheim er overlege og seksjonsleder. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter.Øre-nese-halsavdelingen Akershus universitetssykehus og Klinikk for kirurgiske fag Universitetet i Oslo Han har bidra med idé, revisjon av manus og godkjenning av innsendte versjon av manus. Juha Tapio Silvola er ph.d., overlege, seksjonsleder og professor II. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter.Øre-nese-halsavdelingen St. Olavs hospital Hun har bidra med idé, revisjon av manus og godkjenning av innsendte versjon av manus. Brit Kari Stene er overlege. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter.