Describing the Cellular Impact of IQOS™ Smoke Extract and Vibration on Human Vocal Fold Fibroblasts.

OBJECTIVES: The isolated or combined effects of vibration and smoke extract (SE) from the IQOS™ "heat-not-burn" technology on human vocal fold fibroblasts (hVFF) were evaluated in an in vitro setting in order to elucidate their influence on vocal fold (patho-) physiology. STUDY DESIGN: Experimental pilot study using intervention with IQOS™-SE in vitro. METHODS: Immortalized hVFF were exposed to IQOS™-SE or control medium under static or vibrational conditions. A phonomimetic bioreactor was used to deliver vibrational patterns to hVFF over a period of 5days. Cytotoxicity was quantified by lactate dehydrogenase assay. Effects on extracellular matrix production, inflammation, fibrogenesis, and angiogenesis were assessed by reverse transcription-quantitative polymerase chain reaction, western blot, enzyme-linked immunosorbent assay, and Magnetic Luminex assays. RESULTS: We observed significant changes induced either by IQOS™-SE exposure alone (matrix metalloproteinase 1, fibronectin, cyclooxygenase (COX)1, interleukin-8 gene expression), or by the combination of IQOS™-SE and vibration (hyaluronidase 2, COX2, interleukin-8 protein levels, vascular endothelial growth factor D). CONCLUSION: Short-term in vitro exposure of hVFF to IQOS™-SE did not result in cytotoxicity and reduced the gene expression of measured inflammation mediators, but had no effect on their protein expression. However, the clinical effects of long-term IQOS™ use are still not known and further research is needed in order to assess, if IQOS™ is in fact less harmful than conventional cigarettes.

Vocal fold fibroblasts and exposure to vibration in vitro: Does sex matter?

Studies have shown that certain vocal fold pathologies are more common in one sex than the other. This is often explained by differences in the composition of the lamina propria and anatomical differences between female and male vocal folds, resulting in e.g. different fundamental frequencies. Here, we investigated a potential sex-specific voice frequency effect in an in vitro setting using vocal fold fibroblasts from one male and one female donor with and without cigarette smoke extract (CSE) addition. After exposure to either male or female vibration frequency with or without CSE, cells and supernatants were harvested. Gene and protein analysis were performed by means of qPCR, western blot, ELISA and Luminex. We found that exposure of cells to both male and female vibration pattern did not elicit significant changes in the expression of extracellular matrix-, inflammation-, and fibrosis-related genes, compared to control cells. The addition of CSE to vibration downregulated the gene expression of COL1A1 in cells exposed to the female vibration pattern, as well as induced MMP1 and PTGS2 in cells exposed to both female and male vibration pattern. The protein expression of MMP1 and COX2 was found to be significantly upregulated only in cells exposed to CSE and female vibration pattern. To conclude, different vibration patterns alone did not cause different responses of the cells. However, the female vibration pattern in combination with CSE had a tendency to elicit/maintain more pro-inflammatory responses in cells than the male vibration pattern.

Bilateral Functional Electrical Stimulation for the Treatment of Presbyphonia in a Sheep Model.

OBJECTIVES: The aim of the study was to increase muscle volume and improve phonation characteristics of the aged ovine larynx by functional electrical stimulation (FES) using a minimally invasive surgical procedure. METHODS: Stimulation electrodes were placed bilaterally near the terminal adduction branch of the recurrent laryngeal nerves (RLN). The electrodes were connected to battery powered pulse generators implanted subcutaneously at the neck region. Training patterns were programmed by an external programmer using a bidirectional radio frequency link. Training sessions were repeated automatically by the implant every other day for 1 week followed by every day for 8 weeks in the awake animal. Another group of animals were used as sham, with electrodes positioned but not connected to an implant. Outcome parameters included gene expression analysis, histological assessment of muscle fiber size, functional analysis, and volumetric measurements based on three-dimensional reconstructions of the entire thyroarytenoid muscle (TAM). RESULTS: Increase in minimal muscle fiber diameter and an improvement in vocal efficiency were observed following FES, compared with sham animals. CONCLUSION: This is the first study to demonstrate beneficial effects in the TAM of FES at molecular, histological, and functional levels. FES of the terminal branches of the RLN reversed the effects of age-related changes and improved vocal efficiency. LEVEL OF EVIDENCE: NA Laryngoscope, 134:848-854, 2024.

Effect of functional electric stimulation on phonation in an ex vivo aged ovine model.

With age, the atrophy of the thyroarytenoid muscle (TAM), and thus atrophy of the vocal folds, leads to decreased glottal closure, increased breathiness, and a loss in voice quality, which results in a reduced quality of life. A method to counteract the atrophy of the TAM is to induce hypertrophy in the muscle by functional electric stimulation (FES). In this study, phonation experiments were performed with ex vivo larynges of six stimulated and six unstimulated ten-year-old sheep to investigate the impact of FES on phonation. Electrodes were implanted bilaterally near the cricothyroid joint. FES treatment was provided for nine weeks before harvesting. The multimodal measurement setup simultaneously recorded high-speed video of the vocal fold oscillation, the supraglottal acoustic signal, and the subglottal pressure signal. Results of 683 measurements show a 65.6% lower glottal gap index, a 22.7% higher tissue flexibility (measured by the amplitude to length ratio), and a 473.7% higher coefficient of determination (R2) of the regression of subglottal and supraglottal cepstral peak prominence during phonation for the stimulated group. These results suggest that FES improves the phonatory process for aged larynges or presbyphonia.

Exploring the Pathophysiology of Reinke's Edema: The Cellular Impact of Cigarette Smoke and Vibration.

OBJECTIVES: To explore the isolated or combined effects of cigarette smoke extract (CSE) and vibration on human vocal fold fibroblasts (hVFF) in an in vitro setting in order to elucidate their influence in the pathophysiology of Reinke's edema (RE). STUDY DESIGN: Immortalized hVFF were exposed to CSE or control medium under static or vibrational conditions. A phonomimetic bioreactor was used to deliver vibrational patterns to hVFF over a period of 5 days. METHODS: Cytotoxicity was quantified using a lactate dehydrogenase assay. We employed reverse transcription-quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and Magnetic Luminex(R) assays (R&D Systems, Minneapolis, MN) to assess the influence on extracellular matrix production, fibrogenesis, inflammation, and angiogenesis. RESULTS: We observed significant changes induced by CSE alone (hyaluronic acid, matrix metalloproteinase 1, Interleukin-8, cyclooxygenase [COX]1, COX2, vascular endothelial growth factor [VEGF]D), as well as settings in which only the combination of CSE and vibration led to significant changes (transforming growth factor beta 1, VEGFA, VEGFC). Also, CSE-induced levels of COX2 were only significantly reduced when vibration was applied. CONCLUSION: We were able to explore the cellular effects of CSE and vibration on hVFF by employing a phonomimetic bioreactor. Whereas cigarette smoke is generally accepted as a risk factor for RE, the role of vibration remained unclear as it is difficult to study in humans. Our data showed that some genes and proteins in the pathophysiological context of RE were only affected when CSE in combination with vibration was applied. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E547-E554, 2021.

In vitro mechanical vibration down-regulates pro-inflammatory and pro-fibrotic signaling in human vocal fold fibroblasts.

INTRODUCTION: Voice rest following phonotrauma or phonosurgery has a considerable clinical impact, but clinical recommendations are inconsistent due to inconclusive data. As biopsies of the vocal folds (VF) for molecular biology studies in humans are unethical, we established a new in vitro model to explore the effects of vibration on human vocal fold fibroblasts (hVFF) in an inflammatory and normal state, which is based on previously published models. METHODS: By using a phonomimetic bioreactor we were able to apply predefined vibrational stress patterns on hVFF cultured under inflammatory or normal conditions. Inflammatory and pro-fibrotic stimuli were induced by interleukin (IL)1ß and transforming growth factor (TGF)ß1, respectively. Mechanical stimulation was applied four hours daily, over a period of 72 hours. Outcome measurements comprised assessment of extracellular matrix (ECM)-related components, angiogenic factors, and inflammatory and fibrogenic markers on gene expression and protein levels. RESULTS: Under inflammatory conditions, the inflammatory cytokine IL11, as well as the myofibroblast marker alpha smooth muscle actin (α-SMA) were significantly reduced when additional vibration was applied. The desirable anti-fibrotic ECM component hyaluronic acid was increased following cytokine treatment, but was not diminished following vibration. CONCLUSION: Our experiments revealed the effect of vibrational stress on hVFF in an inflammatory state. Elevated levels of certain pro-inflammatory/pro-fibrotic factors could be mitigated by additional vibrational excitation in an in vitro setting. These findings corroborate clinical studies which recommend early voice activation following an acute event.

Functional Electrical Stimulation for Presbyphonia: A Prospective Randomized Trial.

OBJECTIVES: The aim of this prospective study was to examine the effects of transcutaneous functional electrical stimulation (FES) in a group of elderly women with presbyphonia. STUDY DESIGN: Prospective randomized study. METHODS: Fourteen participants were enrolled prospectively and attributed randomly to two different treatment groups, where one group (n = 7) received 8 weeks of training (5 days a week), whereas the other group (n = 7) received 4 weeks of ineffective stimulation, followed by 4 weeks of effective training. Stimulation protocols were established during baseline examination and confirmed with endoscopy to ensure a glottal reaction. Numerous acoustical, vocal, patient-centered, and respiratory parameters were obtained at several time points. RESULTS: Neither 4 weeks nor 8 weeks of functional electrical transcutaneous stimulation led to changes of vocal, acoustical, or respiratory parameters, apart from patient-centered items (Voice Handicap Index 12, Voice-Related Quality of Life), which improved over time. However, there were no differences between the two arms for both items. CONCLUSIONS: Transcutaneous FES over 4 weeks and 8 weeks did not lead to significantly improved objective voice and acoustical parameters, which could be caused by the fact that the muscles of interest cannot be targeted specifically enough. However, we found a significant improvement of subjective voice perception and voice-related quality of life in both groups. We explain this finding with an observer-expectancy effect secondary to the very time-consuming and elaborate study procedures. LEVEL OF EVIDENCE: 1b Laryngoscope, 130:E662-E666, 2020.

Juvenile Ovine Ex Vivo Larynges: Phonatory, Histologic, and Micro CT Based Anatomic Analyses.

It is well known that the phonatory process changes during the life span. However, detailed investigations on potential factors concerned are rare. To deal with this issue, we performed extended biomechanical, macro anatomical, and histological analyses of the contributing laryngeal structures in ex vivo juvenile sheep models. Altogether twelve juvenile sheep larynges were analyzed within the phonatory experiments. Three different elongation levels and 16 different flow levels were applied to achieve a large variety of phonatory conditions. Vocal fold dynamics and acoustical and subglottal signals could be analyzed for 431 experimental runs. Subsequently, for six juvenile larynges microcomputed tomography following virtual 3D reconstruction was performed. The remaining six juvenile larynges as well as six ex vivo larynges from old sheep were histologically and immunohistologically analyzed. Results for juveniles showed more consistent dynamical behavior compared to old sheep larynges due to vocal fold tissue alterations during the life span. The phonatory process in juvenile sheep seems to be more effective going along with a greater dynamic range. These findings are supported by the histologically detected higher amounts of elastin and hyaluronic acid in the lamina propria of the juvenile sheep. The 3D reconstructions of the thyro-arytenoid muscles (TAM) showed a symmetrical shape. Intraindividual volume and surface differences of the TAM were small and comparable to those of aged sheep. However, TAM dimensions were statistically significant smaller for juvenile larynges. Finally, topographical landmarks were introduced for later comparison with other individuals and species. This work resulted in detailed functional, immunohistological, and anatomical information that was not yet reported. This data will also provide reference information for therapeutic strategies regarding aging effects, e.g. laryngeal muscle treatment by functional electrical stimulation.

Development and validation of a novel phonomimetic bioreactor.

Vocal fold fibroblasts (VFF) constitute the main cell type of the vocal fold's lamina propria, produce the extracellular matrix and thereby determine the tissue characteristics. To study VFF behavior under in vitro conditions it is important to mimic the dynamic environment of the in vivo state. The aim of our study was to develop and validate a novel phonomimetic bioreactor system mainly based on commercially available components. The use of cell culture dishes with flexible silicone bottoms in combination with a suitable loudspeaker made it possible to expose the cells to various kinds of phonatory stimuli. The fundamental vibration characteristics of silicone membranes were investigated with and without cell culture medium by laser Doppler vibrometry. Human VFF were seeded in flexible-bottomed plates and placed in a custom-made housing containing a loudspeaker. After the cells were exposed to a predefined audio stimulation protocol, cell viability was assessed and gene as well as protein expression levels were compared to static controls. Laser Doppler vibrometry revealed that addition of cell culture medium changed the resonance frequencies of vibrating membranes. Gene expression of hyaluronan synthase 2, collagen III, fibronectin and TGFß-1 was significantly upregulated in VFF exposed to vibration, compared to static control. Vibration also significantly upregulated collagen I gene and protein expression. We present a new type of phonomimetic bioreactor. Compared to previous models, our device is easy to assemble and cost-effective, yet can provide a wide spectrum of phonatory stimuli based on the entire dynamic range of the human voice. Gene expression data of VFF cultured in our phonomimetic bioreactor show a significant effect of vibration on ECM metabolism, which illustrates the efficacy of our device.

Functional Electrical Stimulation Leads to Increased Volume of the Aged Thyroarytenoid Muscle.

OBJECTIVES/HYPOTHESIS: To reverse sarcopenia and increase the volumes of atrophied laryngeal muscles by functional electrical stimulation (FES) using a minimal invasive surgical procedure in an aged ovine model. STUDY DESIGN: Prospective animal study. METHODS: A stimulation electrode was placed unilaterally near the terminal adduction branch of the recurrent laryngeal nerve (RLN) adjacent to the right cricothyroid joint. The electrode was connected to an implant located subcutaneously at the neck region. Predesigned training patterns were automatically delivered by a bidirectional radio frequency link using a programming device and were repeated automatically by the implant every other day over 11 weeks in the awake animal. Outcome parameters comprised volumetric measurements based on three-dimensional reconstructions of the entire thyroarytenoid muscle (TAM), as well as gene expression analyses. RESULTS: We found significant increases of the volumes of the stimulated TAM of 11% and the TAM diameter at the midmembranous parts of the vocal folds of nearly 40%. Based on gene expression, we did not detect a shift of muscle fiber composition. CONCLUSIONS: FES of the terminal branches of the RLN is a secure and effective way to reverse the effects of age-related TAM atrophy and to increase volumes of atrophied muscles. LEVEL OF EVIDENCE: NA Laryngoscope, 128:2852-2857, 2018.

Phonation Analysis Combined with 3D Reconstruction of the Thyroarytenoid Muscle in Aged Ovine Ex Vivo Larynx Models.

OBJECTIVE: The aim of the study was to establish a basic data set of combined functional and anatomical measures of aged sheep larynges using ex vivo models. Combining these two approaches in one and the same larynx is an unmet goal so far yet is important as newer treatment strategies aim to preserve the organ structure and new assessment tools are required. Ovine larynges were used as their dimensions, and muscle fiber type distribution highly resemble the human larynx. STUDY DESIGN: Ex vivo animal study. METHODS: Larynges of six sheep (~9 years of age) were subjected to ex vivo functional phonatory experiments. Phonatory characteristics were analyzed as a function of longitudinal vocal fold (VF) prestress. Anatomical measurements of the same larynges comprised micro-computed tomography scans followed by three-dimensional (3D) reconstructions. Using specially adapted radiological scan protocols with subsequent 3D reconstruction, muscle volumes, surface areas, and anatomical measurements were computed. RESULTS: Increasing longitudinal prestress yielded higher subglottal pressure (PS) for the same airflow. Quantitative differences to previous studies-such as the increased PS and increased phonation threshold pressure-were detected. We achieved excellent visualization of the laryngeal muscles and framework, resulting in accurate 3D reconstructions for quantitative analysis. We found no significant intraindividual volume differences of the thyroarytenoid muscles. CONCLUSION: The established protocol allows precise functional and anatomical measures. The data created provide a reference data set for upcoming therapeutic strategies (eg, growth factor therapy, functional electrical stimulation) that target essential structures of the VFs such as the laryngeal muscles and/or the VF mucosa.

Correction: Reversing Age Related Changes of the Laryngeal Muscles by Chronic Electrostimulation of the Recurrent Laryngeal Nerve.

[This corrects the article DOI: 10.1371/journal.pone.0167367.].

Reversing Age Related Changes of the Laryngeal Muscles by Chronic Electrostimulation of the Recurrent Laryngeal Nerve.

Age related atrophy of the laryngeal muscles -mainly the thyroarytenoid muscle (TAM)- leads to a glottal gap and consequently to a hoarse and dysphonic voice that significantly affects quality of life. The aim of our study was to reverse this atrophy by inducing muscular hypertrophy by unilateral functional electrical stimulation (FES) of the recurrent laryngeal nerve (RLN) in a large animal model using aged sheep (n = 5). Suitable stimulation parameters were determined by fatiguing experiments of the thyroarytenoid muscle in an acute trial. For the chronic trial an electrode was placed around the right RLN and stimulation was delivered once daily for 29 days. We chose a very conservative stimulation pattern, total stimulation time was two minutes per day, or 0.14% of total time. Overall, the mean muscle fiber diameter of the stimulated right TAM was significantly larger than the non-stimulated left TAM (30µm±1.1µm vs. 28µm±1.1 µm, p<0.001). There was no significant shift in fiber type distribution as judged by immunohistochemistry. The changes of fiber diameter could not be observed in the posterior cricoarytenoid muscle (PCAM). FES is a possible new treatment option for reversing the effects of age related laryngeal muscle atrophy.

Subjective and objective parameters in the evaluation of radiofrequency ablation of the inferior turbinate do not correlate: A pilot study.

Inferior turbinate hypertrophy is a common cause of nasal obstruction. We conducted a prospective study to correlate subjective and objective parameters in assessing the effectiveness of radiofrequency ablation (RFA). Our initial study population was made up of 10 patients who presented with nasal obstruction; 1 patient was lost to follow-up, leaving us with 7 women and 2 men, aged 26 to 65 years (mean: 37.9 ± 12.8), and 16 turbinates (7 bilateral, 1 right, and 1 left). Visual analogue scale (VAS) scores, Nasal Obstruction and Symptom Evaluation (NOSE) questionnaire scores, rhinomanometry results, and CT- and MRI-based volumetry were obtained before RFA and 6 months afterward. For the subjective parameters, the mean pre- and postoperative VAS scores for the 16 turbinates were 6.6 ± 1.6 and 2.8 ± 2.0 (p < 0.001), respectively, and the mean pre- and postoperative NOSE scores in the 9 patients were 15.3 ± 3.1 and 5.8 ± 5.4 (p = 0.003). For the objective parameters, the mean pre- and postoperative rhinomanometry values at 150 Pa were 241.0 ± 141.3 and 265.4 ± 157.3 ml/sec (p = 0.403), and the mean pre- and postoperative volumetry values were 5.3 ± 2.5 and 5.0 ± 2.1 cm(3) (p = 0.551). Note that only the differences in the subjective parameters reached statistical significance. RFA of the inferior turbinates as a treatment for nasal obstruction is safe and easy. However, our study found a discrepancy between the subjective and objective outcomes parameters, as the former showed highly significant improvement and the latter showed only a slight improvement that did not reach statistical significance.

Vivostat®: an autologous fibrin sealant as useful adjunct in endoscopic transnasal CSF-leak repair.

The benefit of fibrin glue for reduction of postoperative CSF-leaks after endoscopic skull base surgery is not clearly evident in literature. However, its use is supposed to be beneficial in fixing grafting material. As of today there is no specific data available for otolaryngological procedures. A retrospective data analysis at a tertiary care referral center on 73 patients treated endoscopically transnasally for CSF-leaks at the ENT-department Graz between 2009 and 2012 was performed. Primary closure rate between conventional fibrin glue and autologous fibrin glue were analyzed. The Vivostat(®) system was used in 33 CSF-leak closures and in 40 cases conventional fibrin glue was used. Comparing the two methods the primary closure rate using the autologous Vivostat(®) system was 75.8 and 85.0 % with conventional fibrin glue. The secondary closure the rates were 90.9 % with Vivostat(®) 92.5 % with conventional fibrin glue. The Vivosat(®) system is a useful adjunct in endoscopic CSF-leak closure. Its advantages over conventional fibrin glue are its application system for fixation of grafting material particularly in underlay techniques. Despite this advantage it cannot replace grafting material or is a substitute for proper endoscopic closure which is reflected by the closure rates.

Feasibility of piezoelectric endoscopic transsphenoidal craniotomy: a cadaveric study.

OBJECTIVE: Endoscopic transsphenoidal approach has become the gold standard for surgical treatment of treating pituitary adenomas or other lesions in that area. Opening of bony skull base has been performed with burrs, chisels, and hammers or standard instruments like punches and circular top knives. The creation of primary bone flaps-as in external craniotomies-is difficult.The piezoelectric osteotomes used in the present study allows creating a bone flap for endoscopic transnasal approaches in certain areas. The aim of this study was to prove the feasibility of piezoelectric endoscopic transnasal craniotomies. Study Design. Cadaveric study. METHODS: On cadaveric specimens (N = 5), a piezoelectric system with specially designed hardware for endonasal application was applied and endoscopic transsphenoidal craniotomies at the sellar floor, tuberculum sellae, and planum sphenoidale were performed up to a size of 3-5 cm(2). RESULTS: Bone flaps could be created without fracturing with the piezoosteotome and could be reimplanted. Endoscopic handling was unproblematic and time required was not exceeding standard procedures. CONCLUSION: In a cadaveric model, the piezoelectric endoscopic transsphenoidal craniotomy (PETC) is technically feasible. This technique allows the surgeon to create a bone flap in endoscopic transnasal approaches similar to existing standard transcranial craniotomies. Future trials will focus on skull base reconstruction using this bone flap.

European position paper on the anatomical terminology of the internal nose and paranasal sinuses.

The advent of endoscopic sinus surgery led to a resurgence of interest in the detailed anatomy of the internal nose and paranasal sinuses. However, the official Terminologica Anatomica used by basic anatomists omits many of the structures of surgical importance. This led to numerous clinical anatomy papers and much discussion about the exact names and definitions for the structures of surgical relevance. This European Position Paper on the Anatomical Terminology of the Internal Nose and Paranasal Sinuses was conceived to re-evaluate the anatomical terms in common usage by endoscopic sinus surgeons and to compare this with the official Terminologica Anatomica. The text is a concise summary of all the structures encountered during routine endoscopic surgery in the nasal cavity, paranasal sinuses and at the interface with the orbit and skull base but does not provide a comprehensive text for advanced skull base surgery. It draws on a detailed review of the literature and provides a consensus where several options are available, defining the anatomical structure in simple terms and in English. It is recognised that this is an area of great variation and some indication of the frequency with which these variants are encountered is given in the text and table. All major anatomical points are illustrated, drawing on the expertise of the multi-national and multi-disciplinary contributors to this project.

Subjective and objective vocal parameters in women with polycystic ovary syndrome.

INTRODUCTION: Despite the relatively high prevalence of the polycystic ovary syndrome (PCOS) affecting up to 15% of all women of reproductive age, only little is known about vocal changes related to this endocrinologic disorder that is characterized by biochemical or clinical hyperandrogenism, impaired cycles, and/or polycystic ovaries. The aim of our study was to describe objective and subjective vocal changes in women with a diagnosed PCOS compared with a control group. MATERIALS AND METHODS: Our study group comprised 34 women-24 cases with confirmed PCOS and 10 controls in whom PCOS was excluded. A complete endocrinologic laboratory status was obtained by all participants; study procedures included a videolaryngostroboscopy, voice recording, and completion of the German version of the Voice Handicap Index. RESULTS: A trend toward lower mean fundamental frequency was detectable, but this failed statistical significance. No differences were found in the objective and subjective voice parameters. CONCLUSION: Elevated serum levels of androgens, as found in women with PCOS, were shown not to have an impact on the subjective and objective voice parameters.

Heat development at nasal endoscopes' tips: danger of tissue damage? A laboratory study.

OBJECTIVES/HYPOTHESIS: The aim of this study was to measure the temperature generated by light sources in conjunction with angulated endoscopes and to analyze whether the heat generated at the endoscopes' tips harbors potential damage to mucosa or highly sensitive structures like the optic nerve or brain when in direct contact, considering a beginning necrosis of human protein starting at 40°C. STUDY DESIGN: Laboratory setting, prospective. METHODS: Brand new 4-mm, 0° and 30° rigid nasal endoscopes were measured each with halogen, xenon, and light-emitting diode (LED) light sources, respectively, at different power levels for tip contact temperature. RESULTS: The highest temperatures were reached with a xenon light source at a maximum of 44.3°C, 65.8°C, and 91.4°C at 33%, 66%, and 100% power levels, respectively, for 4-mm, 0° endoscopes. For 30° endoscopes, temperatures of 47.0°C, 75.1°C, and 95.5°C were measured at 33%, 66%, and 100% power levels (P < .001; 0° vs. 30°), respectively. At 5-mm distance from the tip, temperatures were below body temperature for all light sources (<36°C) at all power settings. Within 2 minutes after switching off light sources, temperatures dropped to room temperature (22°C). CONCLUSIONS: Xenon light sources have the greatest illumination potential; however, at only 33% power level, potentially harmful temperatures can be reached at the tips of the endoscopes. Power LED and halogen have the highest safety; however, only LED has very good illumination. In narrow corridors, direct contact to tissues or vital structures should be avoided, or endoscopes should be cooled during surgical procedures.

Intraoperative medialization of medial rectus muscle as a new endoscopic technique for approaching intraconal lesions.

BACKGROUND: Intraconal tumors of the orbit are rare entities and surgical treatment is challenging. Endoscopic transnasal approaches to the orbit offer a new perspective for surgery, although only few reports exist in literature. This study displays the Graz experience with endoscopic approaches to intraorbital tumors between 2006 and 2010 introducing a novel endoscopic technique for temporary medialization of the medial rectus muscle facilitating access to the orbital cone. METHODS: A retrospective analysis of patients' charts was performed. RESULTS: For approaches to intraconal lesions a special endoscopic temporary medialization technique of the medial rectus muscle through applying transseptal sutures was developed. Six patients (four male and two female patients) have been included in this study presenting with intraconal/intraorbital tumors. Three patients underwent endoscopic surgery for two hemangiomas and one Schwannoma, respectively, and three patients were successfully biopsied endoscopically revealing one malignant melanoma, one malignant lymphoma, and one optic glioma each. Both hemangiomas were completely resected without any deterioration of vision. The Schwannoma was partially resected with postoperative imaging showing no tumor progression within 3 months. No intraoperative complications occurred. Five cases were performed with computer assisted surgery using CT/MR fusion navigation. CONCLUSION: Although technically challenging, the endoscopic approach to the orbit, even for intraconal lesions with medialization of the medial rectus muscle, can be safe and promising for well-selected cases. Good postoperative results and sufficient material acquisition for proper histological examination can be obtained. Advantages are good visualization of the surgical field and avoidance of external scars. Limitations to endoscopic techniques are tumors in the lateral superior and lateral inferior quadrant of the orbit.