Smart Artificial Soft Tissue - Application to a Hybrid Simulator for Training of Laryngeal Pacemaker Implantation.

Surgical simulators are safe and evolving educational tools for developing surgical skills. In particular, virtual and hybrid simulators are preferred due to their detailedness, customization and evaluation capabilities. To accelerate the revolution of a novel class of hybrid simulators, a Smart Artificial Soft Tissue is presented here, that determines the relative position of conductive surgical instruments in artificial soft tissue by inverse resistance mappings without the need for a fixed reference point. This is particularly beneficial for highly deformable structures when specific target regions need to be reached or avoided. The carbon-black-silicone composite used can be shaped almost arbitrarily and its elasticity can be tuned by modifying the silicone base material. Thus, objective positional feedback for haptically correct artificial soft tissue can be ensured. This is demonstrated by the development of a laryngeal phantom to simulate the implantation of laryngeal pacemaker electrodes. Apart from the position-detecting larynx phantom, the simulator uses a tablet computer for the virtual representation of the vocal folds' movements, in accordance with the electrical stimulation by the inserted electrodes. The possibility of displaying additional information about target regions and anatomy is intended to optimize the learning progress and illustrates the extensibility of hybrid surgical simulators.

Electromyography of the posterior cricoarytenoid muscles: a consensus guideline.

PURPOSE: Since the introduction of transcutaneous-transcricoidal needle approaches, electromyography (EMG) of the posterior cricoarytenoid muscle (PCA) became easier to perform and teach. Among the Neurolaryngology working group of the European Laryngological Society, several centers have adopted PCA EMG as part of their routine EMG workup in vocal fold immobility collectively gathering long-term experience. The purpose is to give an update and an extension to already existing guidelines on laryngeal EMG with specific regard to PCA EMG. METHODS: Consensus of all co-authors is based on continuous exchange of ideas and on joint laryngeal EMG workshop experiences over at least 7 years. A Delphi method of consensus development was used, i.e., the manuscript was circulated among the co-authors until full agreement was achieved. RESULTS: Step-by-step instructions on how to perform and interpret PCA EMG are provided. CONCLUSIONS: Further research should include the establishment of normal values for PCA and thyroarytenoid muscle (TA) EMG as well as studies on the nature of some unusual activation pattern commonly seen in chronically lesioned PCA.

Modified vacuum-assisted closure (EndoVAC) therapy for treatment of pharyngocutaneous fistula: Case series and a review of the literature.

BACKGROUND: Pharyngocutaneous fistula is a potential life-threatening complication following head and neck surgery. There is only limited evidence about the efficacy of vacuum-assisted closure (VAC) therapy and endoscopic vacuum-assisted closure (EndoVAC) therapy for the treatment of pharyngocutaneous fistulas. METHODS: In this article, we report on a consecutive case series of six male patients with pharyngocutaneous fistula treated with a modified outside-in EndoVAC technique. We also present a review of the current related literature. RESULTS: EndoVAC therapy alone was successful in five of the six patients (83.3%) with a median duration of EndoVAC therapy of 18.5 days (range: 7 to 32 days) and a median number of EndoVAC sponge changes of 4 (range: 1 to 9 changes). One patient needed additional reconstructive surgery after prior radiochemotherapy and jejunal transfer. No treatment-related complications were observed. CONCLUSION: EndoVAC therapy is an easy-to-perform, safe procedure for the treatment of pharyngocutaneous fistulae.

Objectivation of laryngeal electromyography (LEMG) data: turn number vs. qualitative analysis.

PURPOSE: This paper describes a first attempt to quantify LEMG data based on turn number calculation. The results obtained for both healthy and ailing thyroarytenoid (TA) muscles of patients with unilateral vocal fold immobility (UVFI) were compared with the respective qualitative evaluation concerning volitional activity to determine whether the two types of analyses deliver similar results. METHODS: LEMG data obtained from 44 adults with UVFI were considered for the study. Semiquantitative evaluation of TA volitional activity and turn number were assessed for the ailing and the healthy TA and the difference in percentage was calculated. Paired data were compared with the Wilcoxon signed-rank test. The volitional activity assessment and the turn number evaluation were compared with the Kruskal-Wallis test, and their relationship was tested with the Kendall rank correlation. RESULTS: Datasets of 27 patients were considered compatible with turns/s calculation. The results showed that complete paralysis correlated with no turns; single fiber volitional activity with 62-208 turns/s, strongly decreased volitional activity with 198-501 turns/s; and dense volitional activity with 441-1234 turns/s. On the ailing VF only, the Kruskal-Wallis test showed a statistically significant difference (p = 0.0001), and the Kendall rank correlation a positive relationship (r = 0.853,p ≤ 0.0001) between the volitional activity rating and the turn number assessment. CONCLUSIONS: Our preliminary results showed that turn number evaluation is an effective tool to confirm LEMG qualitative analysis, and that, in combination with laryngostroboscopy and voice assessment, can help improving the accuracy of the diagnosis and prognosis and the effectiveness of the chosen therapy.

Recurrent Laryngeal Nerve Stimulator.

Electrical stimulation of the recurrent laryngeal nerve is a safe and promising therapeutic approach with the potentiality to overcome the shortcomings of conventional surgical glottal enlargement. Although aberrant or synkinetic reinnervation is commonly considered an unfavorable condition, particularly for recovery of vocal fold movement, its presence is essential to ensure the effective clinical performance of laryngeal pacemakers. Thus, the effective selection of patients who can profit from laryngeal pacemakers implantation demands the implementation of new diagnostic tools based on tests capable of reliably detecting the presence of viable reinnervation on at least one vocal fold.

Inter-rater reliability of seven neurolaryngologists in laryngeal EMG signal interpretation.

PURPOSE: Laryngeal electromyography (LEMG) has been considered as gold standard in diagnostics of vocal fold movement impairment, but is still not commonly implemented in clinical routine. Since the signal interpretation of LEMG signals (LEMGs) is often a subjective and semi-quantitative matter, the goal of this study was to evaluate the inter-rater reliability of neurolaryngologists on LEMGs of volitional muscle activity. METHODS: For this study, 52 representative LEMGs of 371 LEMG datasets were selected from a multicenter registry for a blinded evaluation by 7 experienced members of the neurolaryngology working group of the European Laryngological Society (ELS). For the measurement of the observer agreement between two raters, Cohen's Kappa statistic was calculated. For the interpretation of agreements of diagnoses among the seven examiners, we used the Fleiss' Kappa statistic. RESULT: When focusing on the categories "no activity", "single fiber pattern", and "strongly decreased recruitment pattern", the inter-rater agreement varied from Cohen's Kappa values between 0.48 and 0.84, indicating moderate to near-perfect agreement between the rater pairs. Calculating with Fleiss' Kappa, a value of 0.61 showed good agreement among the seven raters. For the rating categories, the Fleiss' Kappa value ranged from 0.52 to 0.74, which also showed a good agreement. CONCLUSION: A good inter-rater agreement between the participating neurolaryngologists was achieved in the interpretation of LEMGs. More instructional courses should be offered to broadly implement LEMG as a reliable diagnostic tool in evaluating vocal fold movement disorders in clinical routine and to develop future algorithms for therapy and computer-assisted examination.

Therapy of bilateral vocal fold paralysis: Real world data of an international multi-center registry.

PURPOSE: To collect data on diagnosis, treatment, patient's management, and quality of life in patient with bilateral vocal fold paralysis (BVFP). METHODS: A retrospective, observational, multicenter registry study was performed. Medical records of 326 adults with permanent BVFP (median age: 61 years; 70% female, 60% after thyroid surgery) generated between 2010 and 2017. RESULTS: Median time between BVFP onset and inclusion was 1.2 years. Median post-treatment follow-up was 2 months (range: 0-42). Surgery was treatment of choice in 61.7% of the cases, with a 2-year revision rate of 32.4%. Prior to inclusion, 40.2% of the patients underwent at least one surgery. For tracheotomized patients, decannulation rate was 33.8%. Non-surgical treatments included voice therapy and botulinum toxin injection. Corticosteroid application was the most frequent treatment for post-treatment complications (18%; 1-month after surgery). Older age was an independent predictor for dyspnea (Hazard ratio [HR] = 1.041; CI = 1.005 to 1.079; p = 0.026) and the need for oxygen treatment (HR = 1.098; CI = 1.009 to 1.196; p = 0.031). Current alcohol consumption (HR = 2.565; CI = 1.232 to 5.342; p = 0.012) and a cancer-related etiology (HR = 4.767; CI = 1.615 to 14.067; p = 0.005) were independent factors of higher revision risk. CONCLUSIONS: Surgery for BVFP is currently not standardized but highly variable. Postoperative and BVFP-related complications and revision surgery are frequent. Complications are linked to patients' alcohol drinking habits and BVFP etiology. These results shall be confirmed by the upcoming evaluation of the prospective data of this registry.

Vocal fold paresis: Medical specialists' opinions on standard diagnostics and laryngeal findings.

PURPOSE: There is still no clear consensus on the diagnostic value of specific laryngeal findings in patients with suspected vocal fold paresis (VFP). The aim of the study was to establish expert opinion on criteria for the diagnosis of VFP in Europe. METHODS: A cross-sectional survey using the questionnaire introduced by Wu and Sulica for US American experts was addressed to laryngeal experts in Germany, Austria, and Switzerland and in a second survey wave to members of the European Laryngological Society. RESULTS: 100 respondents returned survey 1 (response rate 47.2%). 26% worked at a university department. 28% regularly used laryngeal electromyography (LEMG). A pathologic test results in LEMG was considered to have the strongest positive predictive value for VFP (79 ± 23%), followed by a decreased vocal fold abduction (70 ± 29%), decreased vocal fold adduction (61 ± 34%), and atrophy of the hemilarynx (61 ± 31%). The multivariate analysis showed the predictive value of LEMG was estimated lower by respondents from non-university hospital (ß = - 16.33; confidence interval (CI) = - 25.63 to - 7.02; p = 0.001) and higher in hospitals with higher frequency of VFP patients per months (ß = 1.57; CI = - 0.98 to 2.16; p < 0.0001). 30 ELS members returned survey 2 (response rate, 8.4%). Their answers were not significantly different to survey 1. CONCLUSIONS: The laryngology experts in Europe rely on LEMG for diagnosis of VFP like the US American experts, but paradoxically only a minority uses LEMG frequently. Next to LEMG, motion abnormities were considered to have the best predictive value for the diagnosis of VFP.

Use of erbium laser in the treatment of persistent post-radiotherapy laryngeal edema: a case report and review of the literature.

BACKGROUND: Post-radiotherapy laryngeal edema may affect the patients' quality of life, leading to repeated treatment attempts, which include massage/physical therapy, inhalations, and/or tracheostomy. CASE PRESENTATION: We report the surgical treatment approach of a 69-year-old patient with severe persistent post-radiotherapy laryngeal edema. After multiple inpatient admissions and failed conservative therapy, we used the erbium laser to treat the arytenoid edema. After repeated procedures, no complications were observed. The patient remained free of symptoms after 30 months of follow-up. CONCLUSIONS: The authors provide an easy-to-perform, safe, and quick surgical technique without non-severe or severe complications. Using this technique repeatedly, complications from excessive thermal damage with CO2 laser or unpleasant solutions such as tracheostomy can be avoided.

Isolated choanal and gut atresias: pathogenetic role of serine protease inhibitor type 2 (SPINT2) gene mutations unlikely.

BACKGROUND: Choanal (CA) and gastrointestinal atresias (GA) are an important feature of syndromic congenital sodium diarrhea (sCSD), a disorder recently associated with mutations in the gene for serine protease inhibitor type 2 (SPINT2). It is, however, not known whether isolated non-syndromic CA and GA themselves might result from SPINT2 mutations. METHODS: We performed a prospective cohort study to investigate 19 CA and/or GA patients without diarrhea ("non-sCSD") for potential sCSD characteristic clinical features and SPINT2 mutations. RESULTS: We found a heterozygous SPINT2 splice mutation (c.593-1G>A), previously demonstrated in sCSD in homozygous form, in only 1 of the 19 patients of the "non-sCSD" cohort. This patient presented with isolated anal atresia and borderline low laboratory parameters of sodium balance. In the remaining 18 non-sCSD CA/GA patients investigated, SPINT2 sequence analysis and clinical markers of sodium homeostasis were normal. None of the 188 healthy controls tested in a regional Tyrolean population harbored the c.593-1G>A mutation, which is also not listed in the ExAc and gnomAD databases. CONCLUSIONS: The finding of only one heterozygous SPINT2 mutation in 19 patients with isolated CA/GA was not statistically significant. Therefore, SPINT2 mutations are an unlikely cause of non-sCSD atresia. Trial registration ISRCTN73824458. Retrospectively registered 28 September 2014.

[The role of laryngeal electromyography in the diagnosis of vocal cord movement disorders]. / A laryngealis electromyographia szerepe a hangszalag-mozgászavarok diagnosztikájában és az alkalmazott kezelés kiválasztásában.

The development of the therapeutic possibilities of vocal cord immobility necessitated the parallel renewal of diagnostic methods. In the last years, laryngeal electromyography, which was first introduced more than 70 years ago, has been re-discovered. After reviewing the international literature and their own experience, the authors present the indications, technical requirements, method and, particularly, the evaluation of the results of this procedure. Laryngeal electromyography makes the differentiation between mechanical fixation and immobility with neurological origin of the vocal folds possible. In case of laryngeal paralysis/paresis it also evaluates objectively the severity of neural injury, the prognosis of the disease and the necessity of any glottis-widening procedure. The widespread application of dynamic rehabilitation interventions is not conceivable without the routine application of laryngeal electromyography, so this sensitive diagnostic tool has to be introduced in all laryngological centers. Orv Hetil. 2018; 159(8): 303-311.

Laryngeal pacing for bilateral vocal fold paralysis: Voice and respiratory aspects.

OBJECTIVE: To evaluate the effects of neurostimulation with the laryngeal pacemaker (LP) system in patients with bilateral vocal fold paralysis (BVFP) in terms of voice quality and respiratory function. STUDY DESIGN: Feasibility study, first-in-human, single-arm, open-label, prospective, multicenter study with group-sequential design and 6-month follow-up period, as described in details in our previous publication. METHODS: Nine symptomatic BVFP subjects were unilaterally implanted with the LP system at three study sites in Germany and Austria. Subjective and objective voice function, spirometric parameters other than peak expiratory/inspiratory flow (PEF/PIF), and PEF-meter self-assessment were evaluated pre- and 6 months postimplantation. RESULTS: In general, the LP system did not considerably change the voice quality of the implanted patients. Only the sound pressure level range improved significantly 6 months postimplantation (P = 0.018). The LP system implantation did not affect the glottal closure configuration, the duration of the closed phase, and the mucosal wave of the implanted side. The evaluated spirometric parameters were not significantly affected by laryngeal pacing, whereas PEF meter self-assessment showed a stable and significant (P = 0.028) improvement of the PEF within a week upon activation of the LP system. CONCLUSION: Neurostimulation with the LP system results in an immediate and stable PEF improvement, without negative effects on the voice quality. The PEF meter self-assessment confirmed the spirometry results of the PEF. The stimulated abduction did not affect the glottal closure during phonation. These results should be confirmed in larger and more homogenous patient cohorts. LEVEL OF EVIDENCE: 2b Laryngoscope, 127:1838-1844, 2017.

Laryngeal pacing via an implantable stimulator for the rehabilitation of subjects suffering from bilateral vocal fold paralysis: A prospective first-in-human study.

OBJECTIVES/HYPOTHESIS: To evaluate the performance and safety of the newly developed Laryngeal Pacemaker System (LP System) for the treatment of bilateral vocal fold paralysis (BVFP). STUDY DESIGN: Feasibility, first-in-human, single-arm, open-label, prospective, multicenter study with a group sequential design and a 6-month follow-up period. METHODS: Nine symptomatic BVFP subjects were implanted unilaterally with the LP System. Pre- and 6-month postimplantation evaluations consisted of the 6-Minute Walk Test (6MWT), the Peak Expiratory and Inspiratory Flow (PEF and PIF) evaluation, the PEF meter analysis, the 36-Item Short Form Health Survey (SF-36), the Glasgow Benefit Inventory (GBI), the 12-Item Voice Handicap Index (VHI-12), and the Fiberoptic Endoscopic Evaluation of Swallowing. The safety profile of the LP System was continuously monitored. RESULTS: The LP System implantation was achieved in 8/9 cases. Seven of the nine subjects completed the study. Absolute PEF and PIF values improved significantly 6 months postimplantation (P < .05). 6MWT results showed a non-statistically significant improvement (P = .09). The mental component of the SF-36 showed a significant improvement (P = .043), whereas the other SF-36 components, the GBI, and the VHI-12 results did not changed significantly. The LP System did not affect the voice and swallowing quality and maintained a reliable safety profile for the duration of the study. CONCLUSIONS: This feasibility study showed that the LP System has the potential to become an effective and safe treatment for BVFP subjects without compromising the patients' voice. LEVEL OF EVIDENCE: 2b Laryngoscope, 126:1810-1816, 2016.

An unusual cause of inspiratory stridor in the newborn: congenital pharyngeal teratoma--a case report.

BACKGROUND: Neonatal inspiratory stridor is an important examination finding that requires immediate and adequate evaluation of the underlying etiology. Depending on the severity of the airway obstruction and the presence or absence of associated symptoms such as respiratory distress and feeding problems, early initiation of a complete diagnostic workup can be crucial. The most common cause of neonatal inspiratory stridor is laryngomalacia, however, several differential diagnoses need to be investigated. More rare causes include oral or laryngeal masses. Teratomas of the head and neck region are one of the most unusual causes of respiratory distress during the neonatal period. We present a case of a mature teratoma in the oropharynx presenting with airway obstruction in a newborn infant. CASE PRESENTATION: A four-day-old female Caucasian infant was admitted to the neonatal intensive care unit of our hospital because of inspiratory stridor and profound desaturations while feeding. Diagnostic workup by ultrasound, magnetic resonance imaging and flexible endoscopy revealed a pediculated lesion in the pharyngeal region causing intermittent complete airway obstruction. The mass was surgically removed by transoral laser resection on the seventh day of life. Histological evaluation was consistent with a mature teratoma without any signs of malignancy. The further hospital course was uneventful, routine follow-up examinations at 3, 6 and 9 months of age showed no evidence of tumor recurrence. CONCLUSION: Neonatal stridor is a frequent symptom in the neonatal period and is mostly caused by non-life-threatening pathologies. On rare occasions, however, the underlying conditions are more critical. A careful stepwise diagnostic investigation to rule out these conditions, to identify rare causes and to initiate early treatment is therefore warranted.

Teaching laryngeal electromyography.

To achieve consensus in the methodology, interpretation, validity, and clinical application of laryngeal electromyography (LEMG), a working group on neurolaryngology from the European Laryngological Society (ELS) was founded in 2010. The main task of the working group was to teach key techniques like LEMG procedures. The objective of this study was to collect information on the teaching techniques used and describe them. A multicenter registry was created to analyze the data collected from LEMGs in 14 departments. We screened how often different departments participated in teaching events. Teaching events were classified retrospectively: presentations at conferences and meetings; workshops with hands-on training on patients; workshops with hands-on training on animal models; workshops with hands-on training on anatomic specimens; and supervision by experts to perform LEMG together. Both, supervision to perform LEMG together and the total number of PCA-LEMGs (r = 0.713), as well as supervision to perform LEMG together and the PCA/total-number-of-LEMG ratio (r = 0.814) were correlated significantly (p < 0.05). Similarly, the sum of teaching events was correlated significantly with the total number of PCA-LEMGs (r = 0.605), and so did the sum of teaching events with the PCA/total-number-of-LEMG ratio (r = 0.704). Participation in hands-on training in humans was correlated significantly with the PCA/total-number-of-LEMG ratio (r = 0.640). The data presented herein suggest that multimodal teaching techniques are most effective. To promote multimodal learning an interactive webpage ( http://www.lemg.org) providing videos and animations, and the possibility to discuss cases with other experts was established.

Laryngeal electromyography: a proposal for guidelines of the European Laryngological Society.

Although recognized as a valuable diagnostic tool for more than 60 years, many laryngologists do not routinely use laryngeal electromyography (LEMG). This may be due to a persisting lack of agreement on methodology, interpretation, validity, and clinical application of LEMG. To achieve consensus in these fields, a laryngeal electromyography working group of European neurolaryngologic experts was formed in order to (1) evaluate guidelines for LEMG performance and (2) identify issues requiring further clarification. To obtain an overview of existing knowledge and research, English-language literature about LEMG was identified using Medline. Additionally, cited works not detected in the initial search were screened. Evidence-based recommendations for the performance and interpretation of LEMG and also for electrostimulation for functional evaluation were considered, as well as published reports based on expert opinion and single-institution retrospective case series. To assess the data obtained by this literature evaluation, the working group met five times and performed LEMG together on more than 20 patients. Subsequently, the results were presented and discussed at the 8th Congress of the European Laryngological Society in Vienna, Austria, September 1-4, 2010, and consensus was achieved in the following areas: (1) minimum requirements for the technical equipment required to perform and record LEMG; (2) best practical implementation of LEMG; (3) criteria for interpreting LEMG. Based on this consensus, prospective trials are planned to improve the quality of evidence guiding the proceedings of practitioners.