Laryngological presentations and patient-reported outcome measures in Ehlers-Danlos syndrome.

OBJECTIVE: This study aimed to characterise the laryngological presentations of Ehlers-Danlos syndrome and conduct a preliminary exploration of patient-reported outcome measures. METHODS: This paper describes a retrospective case series of patients with Ehlers-Danlos syndrome seen by the senior author between 2005 and 2019. A literature review was conducted to summarise the existing findings. RESULTS: Twenty-one patients met the inclusion criteria. All reported symptoms were grouped; this showed that swallowing, voice and hyolaryngeal skeletal complex problems were commonest. Patient-reported outcome measures were available for eight patients, which showed large variations in: the Reflux Severity Index (median = 25.5; range = 0-33), Eating Assessment Tool score (median = 21.5; range = 0-35) and Voice Handicap Index (median = 21.5; range = 0-104). Twelve studies met our literature review inclusion criteria, involving at least 91 patients with laryngological presentations of Ehlers-Danlos syndrome. CONCLUSION: Ehlers-Danlos syndrome patients experience musculoskeletal issues, which in the throat manifest as hyolaryngeal skeletal complex problems. Future studies with larger patient numbers are required to validate laryngological patient-reported outcome measure tools in Ehlers-Danlos syndrome.

Multidisciplinary guidance for safe tracheostomy care during the COVID-19 pandemic: the NHS National Patient Safety Improvement Programme (NatPatSIP).

The COVID-19 pandemic is causing a significant increase in the number of patients requiring relatively prolonged invasive mechanical ventilation and an associated surge in patients who need a tracheostomy to facilitate weaning from respiratory support. In parallel, there has been a global increase in guidance from professional bodies representing staff who care for patients with tracheostomies at different points in their acute hospital journey, rehabilitation and recovery. Of concern are the risks to healthcare staff of infection arising from tracheostomy insertion and caring for patients with a tracheostomy. Hospitals are also facing extraordinary demands on critical care services such that many patients who require a tracheostomy will be managed outside established intensive care or head and neck units and cared for by staff with little tracheostomy experience. These concerns led NHS England and NHS Improvement to expedite the National Patient Safety Improvement Programme's 'Safe Tracheostomy Care' workstream as part of the NHS COVID-19 response. Supporting this workstream, UK stakeholder organisations involved in tracheostomy care were invited to develop consensus guidance based on: expert opinion; the best available published literature; and existing multidisciplinary guidelines. Topics with direct relevance for frontline staff were identified. This consensus guidance includes: infectivity of patients with respect to tracheostomy indications and timing; aerosol-generating procedures and risks to staff; insertion procedures; and management following tracheostomy.

Improving cellular migration in tissue-engineered laryngeal scaffolds.

OBJECTIVE: To modify the non-porous surface membrane of a tissue-engineered laryngeal scaffold to allow effective cell entry. METHODS: The mechanical properties, surface topography and chemistry of polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane were characterised. A laser technique introduced surface perforations. Micro computed tomography generated porosity data. Scaffolds were seeded with cells, investigated histologically and proliferation studied. Incubation and time effects were assessed. RESULTS: Laser cutting perforated the polymer, connecting the substructure with the ex-scaffold environment and increasing porosity (porous, non-perforated = 87.9 per cent; porous, laser-perforated at intensities 3 = 96.4 per cent and 6 = 89.5 per cent). Cellular studies confirmed improved cell viability. Histology showed cells adherent to the scaffold surface and cells within perforations, and indicated that cells migrated into the scaffolds. After 15 days of incubation, scanning electron microscopy revealed an 11 per cent reduction in pore diameter, correlating with a decrease in Young's modulus. CONCLUSION: Introducing surface perforations presents a viable method of improving polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane as a tissue-engineered scaffold.

In vivo implantation of a tissue engineered stem cell seeded hemi-laryngeal replacement maintains airway, phonation, and swallowing in pigs.

Laryngeal functional impairment relating to swallowing, vocalisation, and respiration can be life changing and devastating for patients. A tissue engineering approach to regenerating vocal folds would represent a significant advantage over current clinical practice. Porcine hemi-larynx were de-cellularised under negative pressure. The resultant acellular scaffold was seeded with human bone marrow derived mesenchymal stem cells and primary human epithelial cells. Seeded scaffolds were implanted orthotopically into a defect created in the thyroid cartilage in 8 pigs and monitored in vivo for 2 months. In vivo assessments consisted of mucosal brushing and bronchoscopy at 1, 2, 4, and 8 weeks post implantation followed by histological evaluation post termination. The implanted graft had no adverse effect on respiratory function in 6 of the 8 pigs; none of the pigs had problems with swallowing or vocalisation. Six out of the 8 animals survived to the planned termination date; 2 animals were terminated due to mild stenosis and deep tissue abscess formation, respectively. Human epithelial cells from mucosal brushings could only be identified at Weeks 1 and 4. The explanted tissue showed complete epithelialisation of the mucosal surface and the development of rudimentary vocal folds. However, there was no evidence of cartilage remodelling at the relatively early censor point. Single stage partial laryngeal replacement is a safe surgical procedure. Replacement with a tissue engineered laryngeal graft as a single procedure is surgically feasible and results in appropriate mucosal coverage and rudimentary vocal fold development.

Immediate selective laryngeal reinnervation in vagal paraganglioma patients.

OBJECTIVE: This prospective case series aimed to present the outcomes of immediate selective laryngeal reinnervation. METHODS: Two middle-aged women with vagal paraganglioma undergoing an excision operation underwent immediate selective laryngeal reinnervation using the phrenic nerve and ansa cervicalis as the donor nerve. Multidimensional outcome measures were employed pre-operatively, and at 1, 6 and 12 months post-operatively. RESULTS: The voice handicap index-10 score improved from 23 (patient 1) and 18 (patient 2) at 1 month post-operation, to 5 (patient 1) and 1 (patient 2) at 12 months. The Eating Assessment Tool 10 score improved from 20 (patient 1) and 24 (patient 2) at 1 month post-operation, to 3 (patient 1) and 1 (patient 2) at 12 months. There was slight vocal fold abduction observed in patient one and no obvious abduction in patient two. CONCLUSION: Selective reinnervation is safe to perform following vagal paraganglioma excision conducted on the same side. Voice and swallowing improvements were demonstrated, but no significant vocal fold abduction was achieved.

Developing control algorithms of a voluntary cough for an artificial bioengineered larynx using surface electromyography of chest muscles: A prospective cohort study.

OBJECTIVE: This prospective cohort study investigates the prediction of a voluntary cough using surface electromyography (EMG) of intercostal and diaphragm muscles, to develop control algorithms for an EMG-controlled artificial larynx. SETTING: The Ear Institute, London. MAIN OUTCOME MEASURES: Electromyography onset compared to voluntary cough exhalation onset and to 100 ms (to give the artificial larynx the time to close the bioengineered vocal cords) before voluntary cough exhalation onset, in twelve healthy participants. RESULTS: In the 189 EMG of intercostal muscle-detected voluntary coughs, 172 coughs (91% CI 70-112) were detected before onset of cough exhalation and 128 coughs (67.6% CI 33.7-101.7) 100 ms before onset of cough exhalation. In the 158 EMG of diaphragm muscle-detected voluntary coughs, 149 coughs (94.3% CI 76.3-112.3) were detected before onset of cough exhalation and 102 coughs (64.6% CI 26.6-102.6) 100 ms before onset of cough exhalation. More coughs were detected before onset of cough exhalation when combining EMG activity of intercostal and diaphragm muscles and comparing this to intercostal muscle activity alone (183 coughs [96.8% CI 83.8-109.8] vs 172 coughs, P = .0294). When comparing the mentioned combination to diaphragm muscle activity alone, the higher percentage of detected coughs before cough exhalation onset was not found to be significant (183 coughs vs 149 coughs, P = .295). In addition, more coughs were detected 100 ms before onset of cough exhalation with the mentioned combination of EMG activity and comparing this to intercostal muscles alone (149 coughs [78.8% CI 48.8-108.8] vs 128 coughs, P = .0198) and to diaphragm muscles alone (149 coughs vs 102 coughs, P = .0038). CONCLUSIONS: Most voluntary coughs can be predicted based on combined EMG signals of intercostal and diaphragm muscles, and therefore, these two muscle groups will be useful in controlling the bioengineered vocal cords within the artificial larynx during a voluntary cough.

Pilot study of a novel vacuum-assisted method for decellularization of tracheae for clinical tissue engineering applications.

Tissue engineered tracheae have been successfully implanted to treat a small number of patients on compassionate grounds. The treatment has not become mainstream due to the time taken to produce the scaffold and the resultant financial costs. We have developed a method for decellularization (DC) based on vacuum technology, which when combined with an enzyme/detergent protocol significantly reduces the time required to create clinically suitable scaffolds. We have applied this technology to prepare porcine tracheal scaffolds and compared the results to scaffolds produced under normal atmospheric pressures. The principal outcome measures were the reduction in time (9 days to prepare the scaffold) followed by a reduction in residual DNA levels (DC no-vac: 137.8±48.82 ng/mg vs. DC vac 36.83±18.45 ng/mg, p<0.05.). Our approach did not impact on the collagen or glycosaminoglycan content or on the biomechanical properties of the scaffolds. We applied the vacuum technology to human tracheae, which, when implanted in vivo showed no significant adverse immunological response. The addition of a vacuum to a conventional decellularization protocol significantly reduces production time, whilst providing a suitable scaffold. This increases clinical utility and lowers production costs. To our knowledge this is the first time that vacuum assisted decellularization has been explored. Copyright © 2015 John Wiley & Sons, Ltd.

Characterization of a biologically derived rabbit tracheal scaffold.

There is a clinical need to provide replacement tracheal tissue for the pediatric population affected by congenital defects, as current surgical solutions are not universally applicable. A potential solution is to use tissue engineered scaffold as the framework for regenerating autologous tissue. Rabbit trachea were used and different detergents (Triton x-100 and sodium deoxycholate) and enzymes (DNAse/RNAse) investigated to create a decellularization protocol. Each reagent was initially tested individually and the outcome used to design a combined protocol. At each stage the resultant scaffold was assessed histologically, molecularly for acellularity and matrix preservation. Immunogenicity of the final scaffold was assessed by implantation into a rat model for 4 weeks. Both enzymes and detergents were required to produce a completely acellular (DNA content 42.78 ng/mg) scaffold with preserved collagen and elastin however, GAG content were reduced (8.78 ± 1.35 vs. 5.5 ± 4.8). Following in vivo implantation the scaffold elicited minimal immune response and showed significant cellular infiltration and vasculogenesis. The luminal aspect of the implanted scaffold showed infiltration of host derived cells, which were positive for pan cytokeratin. It is possible to create biologically derived biocompatible scaffolds to address specific pediatric clinical problems. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2126-2135, 2017.

Caustic ingestion injury of the upper aerodigestive tract in adults.

Adult ingestion of caustic substances is an unusual but serious surgical problem, with injuries likely to be more extensive than those in the corresponding paediatric population. After initial stabilisation and airway management, clinicians are presented with a complex multisystemic problem, frequently requiring a multidisciplinary approach involving several surgical disciplines and associated therapies. A new multidisciplinary team was convened to discuss complex ingestion injury in adults and established techniques were used to bring forward a proposed treatment algorithm. An algorithm may potentially improve clinical efficacy and risk in the management of these complex patients.

Patient perception of a randomised, controlled trial of laryngeal reinnervation versus thyroplasty for unilateral vocal fold paralysis.

OBJECTIVES: To explore unilateral vocal fold paralysis patients' perception of a proposed randomised, controlled trial of laryngeal reinnervation versus thyroplasty, and to identify patients' concerns regarding their voice. METHODS: Seventeen patients from five voice clinics in London were identified as being eligible for the randomised, controlled trial. Eleven of these patients (9 females and 2 males; age range, 18-65 years) were interviewed using a semi-structured topic guide (they were given a minimum of 2 weeks to read through the study information sheet). The interviews were recorded, transcribed and analysed using thematic analysis. RESULTS: The patients were satisfied with the clarity of the information sheet. Most of them perceived that reinnervation was a more 'attractive' option than thyroplasty. This may have been the result of certain phraseology used in the information sheet and by recruiters. Patients' main concern was reduced voice strength and the effects of this on work and social life. CONCLUSION: Phraseology that needed changing was identified; these changes may optimise the recruitment process for a trial. We propose using the voice handicap index 10 as the primary measure of outcome in the proposed randomised, controlled trial.

Regenerative medicine in otorhinolaryngology.

BACKGROUND: Tissue engineering using biocompatible scaffolds, with or without cells, can permit surgeons to restore structure and function following tissue resection or in cases of congenital abnormality. Tracheal regeneration has emerged as a spearhead application of these technologies, whilst regenerative therapies are now being developed to treat most other diseases within otolaryngology. METHODS AND RESULTS: A systematic review of the literature was performed using Ovid Medline and Ovid Embase, from database inception to 15 November 2014. A total of 561 papers matched the search criteria, with 76 fulfilling inclusion criteria. Articles were predominantly pre-clinical animal studies, reflecting the current status of research in this field. Several key human research articles were identified and discussed. CONCLUSION: The main issues facing research in regenerative surgery are translation of animal model work into human models, increasing stem cell availability so it can be used to further research, and development of better facilities to enable implementation of these advances.

Tissue-Engineered Tracheal Replacement in a Child: A 4-Year Follow-Up Study.

In 2010, a tissue-engineered trachea was transplanted into a 10-year-old child using a decellularized deceased donor trachea repopulated with the recipient's respiratory epithelium and mesenchymal stromal cells. We report the child's clinical progress, tracheal epithelialization and costs over the 4 years. A chronology of events was derived from clinical notes and costs determined using reference costs per procedure. Serial tracheoscopy images, lung function tests and anti-HLA blood samples were compared. Epithelial morphology and T cell, Ki67 and cleaved caspase 3 activity were examined. Computational fluid dynamic simulations determined flow, velocity and airway pressure drops. After the first year following transplantation, the number of interventions fell and the child is currently clinically well and continues in education. Endoscopy demonstrated a complete mucosal lining at 15 months, despite retention of a stent. Histocytology indicates a differentiated respiratory layer and no abnormal immune activity. Computational fluid dynamic analysis demonstrated increased velocity and pressure drops around a distal tracheal narrowing. Cross-sectional area analysis showed restriction of growth within an area of in-stent stenosis. This report demonstrates the long-term viability of a decellularized tissue-engineered trachea within a child. Further research is needed to develop bioengineered pediatric tracheal replacements with lower morbidity, better biomechanics and lower costs.

Development of resorbable nanocomposite tracheal and bronchial scaffolds for paediatric applications.

BACKGROUND: Congenital tracheal defects and prolonged intubation following premature birth have resulted in an unmet clinical need for tracheal replacement. Advances in stem cell technology, tissue engineering and material sciences have inspired the development of a resorbable, nanocomposite tracheal and bronchial scaffold. METHODS: A bifurcated scaffold was designed and constructed using a novel, resorbable nanocomposite polymer, polyhedral oligomeric silsesquioxane poly(ϵ-caprolactone) urea urethane (POSS-PCL). Material characterization studies included tensile strength, suture retention and surface characteristics. Bone marrow-derived mesenchymal stem cells (bmMSCs) and human tracheobronchial epithelial cells (HBECs) were cultured on POSS-PCL for up to 14 days, and metabolic activity and cell morphology were assessed. Quantum dots conjugated to RGD (l-arginine, glycine and l-aspartic acid) tripeptides and anticollagen type I antibody were then employed to observe cell migration throughout the scaffold. RESULTS: POSS-PCL exhibited good mechanical properties, and the relationship between the solid elastomer and foam elastomer of POSS-PCL was comparable to that between the cartilaginous U-shaped rings and interconnective cartilage of the native human trachea. Good suture retention was also achieved. Cell attachment and a significant, steady increase in proliferation were observed for both cell types (bmMSCs, P = 0·001; HBECs, P = 0·003). Quantum dot imaging illustrated adequate cell penetration throughout the scaffold, which was confirmed by scanning electron microscopy. CONCLUSION: This mechanically viable scaffold successfully supports bmMSC and HBEC attachment and proliferation, demonstrating its potential as a tissue-engineered solution to tracheal replacement.

Reliability of OperaVOX against Multidimensional Voice Program (MDVP).

OBJECTIVE: To evaluate the agreement between OperaVOX and MDVP. DESIGN: Cross sectional reliability study. SETTING: University teaching hospital. METHODS: Fifty healthy volunteers and 50 voice disorder patients had supervised recordings in a quiet room using OperaVOX by the iPod's internal microphone with sampling rate of 45 kHz. A five-seconds recording of vowel/a/was used to measure fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR). All healthy volunteers and 21 patients had a second recording. The recorded voices were also analysed using the MDVP. The inter- and intrasoftware reliability was analysed using intraclass correlation (ICC) test and Bland-Altman (BA) method. Mann-Whitney test was used to compare the acoustic parameters between healthy volunteers and patients. RESULTS: Nine of 50 patients had severe aperiodic voice. The ICC was high with a confidence interval of >0.75 for the inter- and intrasoftware reliability except for the NHR. For the intersoftware BA analysis, excluding the severe aperiodic voice data sets, the bias (95% LOA) of F0, jitter, shimmer and NHR was 0.81 (11.32, -9.71); -0.13 (1.26, -1.52); -0.52 (1.68, -2.72); and 0.08 (0.27, -0.10). For the intrasoftware reliability, it was -1.48 (18.43, -21.39); 0.05 (1.31, -1.21); -0.01 (2.87, -2.89); and 0.005 (0.20, -0.18), respectively. Normative data from the healthy volunteers were obtained. There was a significant difference in all acoustic parameters between volunteers and patients measured by the Opera-VOX (P < 0.001) except for F0 in females (P = 0.87). CONCLUSION: OperaVOX is comparable to MDVP and has high internal consistency for measuring the F0, jitter and shimmer of voice except for the NHR.

Tissue banking in ENT: challenges and methods.

BACKGROUND: Biobanking is the process of storing high quality human biospecimens alongside linked clinical data, for research purposes. The aim is to identify novel biomarkers with prognostic or diagnostic significance. However, the challenges implicit in the collection and storage of human tissue for research have curtailed the impact of this technique to date. AIM: This paper aims to summarise the challenges faced by biobanking within the ENT specialty in the UK, and to present protocols used for the routine collection, freezing and storage of tissue specimens at the Royal National Throat, Nose and Ear Hospital. These protocols could be used to guide other ENT departments (in the UK and worldwide) wishing to initiate the routine collection and storage of tissue samples. Their publication could also help to establish basic standards and ensure consistency in ENT tissue storage. METHODS: Interviews conducted with industry experts, and a literature review of 'best practice' in biobanking. CONCLUSION: The ENT specialty must stay abreast of progress in human tissue research in order to ensure the best possible management of its patients. Our protocol for the routine banking of ENT tissue at the Royal National Throat, Nose and Ear Hospital could be used as a template for other ENT departments (in the UK and worldwide) to encourage widespread implementation of high quality tissue banking.