Contrast-enhanced ultrasound for the preoperative assessment of laryngeal carcinoma: a preliminary study.

BACKGROUND: Contrast-enhanced ultrasound (CEUS) is considered an attractive imaging technique to evaluate tumor microcirculation. However, the validity of CEUS for assessing laryngeal carcinoma is unclear. PURPOSE: To compare the performance of CEUS with conventional US and contrast-enhanced computed tomography (CECT) in the diagnosis and preoperative T-staging of laryngeal carcinoma. MATERIAL AND METHODS: Forty-one consecutive patients with laryngeal carcinoma underwent conventional high-frequency US, CEUS, and CECT before surgery. The CEUS characteristics of laryngeal carcinoma were recorded. The imaging findings of CEUS and conventional US were compared with CECT findings and the postoperative pathological examination. RESULTS: CEUS showed hyperenhancement in 38 cases and isoenhancement in three cases. Homogeneous distribution of contrast agent was found in 20 cases and heterogeneous distribution in 21 cases, of which 16 cases showed local perfusion defects. In the enhanced phase, rapid entry was observed in 37 cases, synchronous entry was observed in two cases, and slow entry was observed in two cases. Rapid exit was observed in 25 cases and slow exit was observed in 16 cases. The pretherapeutic T-staging accuracy was not significantly different between conventional US, CEUS, and CECT (P ≥ 0.500). A high sensitivity and specificity were achieved by CEUS in the evaluation of involvement of thyroid cartilage. CONCLUSION: Compared with conventional US and CECT, CEUS has a reliable initial T-staging accuracy and diagnostic properties for detecting laryngeal cartilage invasion.

Coverage for Gender-Affirming Voice Surgery and Therapy for Transgender Individuals.

OBJECTIVES/HYPOTHESIS: To determine insurance coverage for gender-affirming surgery and voice therapy for individuals who seek to align their voice with their gender identity, and to analyze differences based on state-by-state transgender equality. STUDY DESIGN: Cross-sectional study. METHODS: Policies from the top three commercial insurers per state in 2019 were reviewed. Coverage status was determined by web-based search, telephone interviews, and email inquiries. A state-by-state equality score was calculated based on the number of laws and policies relating to the transgender community. Correlation between number of preauthorized procedures and state equality scores was assessed. RESULTS: Of the 150 insurance companies reviewed, only four (2.7%) held favorable policies, whereas 113 (75.8%) provided no coverage. Endoscopic surgery, open surgery, individual voice therapy, and group voice therapy interventions were equally excluded (n = 93, 62.4%). Coverage was not correlated with laws driving transgender equality (P = .782). CONCLUSIONS: Gender-affirming voice interventions are seldom covered by commercial insurance companies. Despite established medical necessity and years of experience in practice, gender-affirming interventions for voice have not yet been fully considered by third-party payors. Further investigation regarding cost-effectiveness and treatment efficacy is warranted to improve insurance coverage of voice-related gender-affirming care. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E896-E902, 2021.

Extended role of transnasal oesophagoscopy: a review of the literature.

BACKGROUND: Advances in endoscopic technology have allowed transnasal oesophagoscopy to be used for a variety of diagnostic and therapeutic procedures. METHOD: A review of the literature was carried out to look into the extended role of transnasal oesophagoscopy within otolaryngology, using the Embase, Cinahl and Medline databases. RESULTS: There were 16 studies showing that transnasal oesophagoscopy is safe and cost effective and can be used for removal of foreign bodies, tracheoesophageal puncture, laser laryngeal surgery and balloon dilatation. CONCLUSION: This study presents a summary of the literature showing that transnasal oesophagoscopy can be used as a safe and cost-effective alternative or adjunct to traditional rigid endoscopes for therapeutic procedures.

Office-based vs. operating room-performed laryngopharyngeal surgery: a review of cost differences.

PURPOSE: Office-based transnasal flexible endoscopic surgery under topical anesthesia has recently been developed as an alternative for transoral laryngopharyngeal surgery under general anesthesia. The aim of this study was to evaluate differences in health care costs between the two surgical settings. METHODS: PubMed, EMBASE and Cochrane Library were searched for studies reporting on costs of laryngopharyngeal procedures that could either be performed in the office or operating room (i.e., laser surgery, biopsies, vocal fold injection, or hypopharyngeal or esophageal dilation). Quality assessment of the included references was performed. RESULTS: Of 2953 identified studies, 13 were included. Quality assessment revealed that methodology differed significantly among the included studies. All studies reported lower costs for procedures performed in the office compared to those performed in the operating room. The variation within reported hospital and physician charges was substantial. CONCLUSION: Office-based laryngopharyngeal procedures under topical anesthesia result in lower costs compared to similar procedures performed under general anesthesia.

Airway management changes associated with rising radiologic incidence of external laryngotracheal injury.

BACKGROUND: Traumatic laryngeal injuries are uncommon life-threatening injuries that require prompt, rational management of a potentially precarious airway. It is unclear whether the current incidence of laryngotracheal injury is due to enhanced injury detection or increased occurrence. The objective of this study was to evaluate the relations between diagnostic imaging with both initial airway management and surgical treatment in patients with external laryngotracheal injuries (ELTIs) in Alberta. METHODS: In this large-scale population-based analysis, we used regional health databases containing inpatient admissions, emergency department visits and trauma service activations employing International Classification of Diseases diagnostic codes to identify all ELTIs diagnosed from Apr. 1, 1995, to Dec. 31, 2011, in adults (age ≥ 16 yr). We evaluated health records and diagnostic imaging for injury features, airway management, operative interventions and hospital length of stay (LOS). RESULTS: Eighty-nine patients met the inclusion criteria. The incidence of ELTIs increased over time, paralleling a rise in detection during the period incorporating greater computed tomography (CT) use (p = 0.002). Endotracheal tube intubation was performed in 8/30 cases (27%) in the pre-CT era, compared to 38/59 cases (64%) in the post-CT era (p = 0.001); the use of surgical intervention remained consistent. The largest contributors to increased endotracheal tube placements were the emergency department and emergency medical services. No change in survival was detected, but mean LOS among patients admitted for minor, isolated ELTIs increased by 2.3 (95% confidence interval 0.14-4.8) days (p = 0.06), mostly for patients admitted under critical care for mechanical ventilation. CONCLUSION: Management of ELTIs shifted from predominantly conservative airway monitoring to endotracheal tube intubation over the study period in spite of no clinically significant change in injury severity or operative intervention frequency. The location of endotracheal tube placement suggests less comfort with ELTI among first-responder and emergency personnel.

CONTEXTE: Les lésions traumatiques du larynx sont des blessures rares qui peuvent être mortelles et nécessitent une prise en charge rapide et efficiente, en raison de l'état potentiellement précaire des voies respiratoires. On ignore si l'incidence actuelle des lésions laryngo-trachéales est attribuable à une amélioration de la détection ou à une augmentation de la fréquence réelle. Cette étude avait pour but d'évaluer le lien entre l'imagerie diagnostique, et la prise en charge initiale des voies respiratoires ainsi que le traitement chirurgical chez des patients ayant subi des lésions laryngo-trachéales externes (LLTE) en Alberta. MÉTHODES: Dans le cadre de cette analyse de grande envergure basée sur une population, nous avons interrogé des bases de données régionales sur les hospitalisations, les consultations aux services d'urgence et la prestation de services de traumatologie. Nous nous sommes servis des codes diagnostiques de la Classification statistique internationale des maladies pour repérer tous les cas de LLTE diagnostiqués entre le 1er avril 1995 et le 31 décembre 2011 chez des adultes (16 ans et plus). Nous avons examiné les dossiers de santé et les résultats d'imagerie diagnostique pour en extraire des données sur les caractéristiques des lésions, la prise en charge des voies respiratoires, les interventions chirurgicales et la durée de séjour à l'hôpital. RÉSULTATS: Au total, 89 patients répondaient aux critères d'inclusion. L'incidence des LLTE a augmenté au fil du temps; en parallèle, l'utilisation répandue de la tomographie par ordinateur a entraîné une augmentation de la détection de ces lésions (p = 0,002). Une intubation trachéale a été réalisée chez 8/30 patients (27 %) pendant la période prétomographie, et chez 38/59 patients (64 %) pendant la période post-tomographie (p = 0,001); le recours à la chirurgie est demeuré constant. L'augmentation du nombre d'intubations est principalement attribuable aux interventions effectuées par le personnel ambulancier et par les services d'urgence. Aucun changement du taux de survie n'a été enregistré; toutefois, la durée de séjour moyenne des patients hospitalisés en raison de LLTE mineures et isolées a augmenté de 2,3 jours (intervalle de confiance à 95 % : 0,14-4,8; p = 0,06), surtout pour les patients admis aux soins intensifs pour recevoir une ventilation mécanique. CONCLUSION: Durant la période à l'étude, la prise en charge des LLTE est passée d'un suivi essentiellement conservateur des voies respiratoires à la prépondérance de l'intubation trachéale, bien qu'aucun changement significatif n'ait été observé quant à la gravité des lésions ou à la fréquence des interventions chirurgicales. Le contexte où ont lieu les intubations laisse croire que le personnel ambulanciers et les premiers intervenants sont moins à l'aise de prendre en charge les LLTE.

Assessment of the feeding Swallowing Impact Survey as a quality of life measure in children with laryngeal cleft before and after repair.

OBJECTIVE: To cross-validate the Feeding Swallowing Impact Survey (FSIS), a quality of life instrument, specifically to a subpopulation of children who aspirate due to laryngeal cleft. INTRODUCTION: The FSIS is a recently validated instrument used to describe caregiver quality of life (QOL) in children with aspiration due to various causes. To cross-validate the FSIS specifically to the subpopulation of children who aspirate due to laryngeal cleft, we tested the hypotheses that caregivers would report significant different scores form baseline if their children improved at the one year mark postintervention due to either successful conservative or surgical measures (discriminant validity) and would not report significant differences in their FSIS reporting if there was no change in their child's aspiration at the one year mark post intervention (convergent validity). METHODS: The FSIS was administered to the caregivers of 35 children (19 male, 16 female; age range: 5-79 months) who aspirate secondary to known laryngeal cleft (diagnosed by suspension laryngoscopy and inspection). All children had a baseline VFSS demonstrating aspiration and documenting what feeding plan to follow and caregivers completed the FSIS at this point as well. All children regardless of whether they were treated by conservative or surgical intervention underwent a follow-up VFSS at the one year post-intervention mark and the caregivers completed a FSIS at this time point as well. RESULTS: Among two distinct sub-populations of children who underwent either successful conservative or surgical treatment for their laryngeal cleft and demonstrated improvement at the one year mark (as defined by a VFSS documented decreased need for thickener by at least one consistency or more) and where we hypothesized that FSIS scores would not be significantly different, the caregivers reported no significant differences in FSIS scores cleft repair (mean FSIS scores 2.45 (SD 0.88)/2.1 (SD 0.94); p = 0.28). Moreover, as another test to convergent validity, for children who underwent either unsuccessful conservative treatment (and subsequently went on to need surgery) or who were not successfully surgically treated for their laryngeal cleft and demonstrated no significant improvement at the one year mark (as defined by a VFSS documented decreased need for thickener by at least one consistency or more), the caregivers reported no significant differences in FSIS scores cleft repair (mean FSIS scores 2.8(SD 0.79)/2.5(SD 0.88); p = 0.69). For divergent validity, two distinct sub-populations of children who underwent either successful or not successful surgical treatment for their laryngeal cleft (demonstrated by either improvement or lack of improvement at the one year mark VFSS as defined by a decreased need for thickener by at least one consistency or more) revealed significant differences in caregiver FSIS scores cleft repair (mean FSIS scores 1.38 (SD 0.32); 32.8 (SD 0.79); p=<0.0002). DISCUSSION: This results of this study provide convergent and divergent validity supporting the cross-validation of the FSIS instrument to be utilized as a validated QOL instrument to evaluate children with aspiration specifically due laryngeal cleft as another tool with which to evaluate the outcomes of medical or surgical interventions for this disorder.

Intraoperative assessment of laryngeal malignancy using elastic light single-scattering spectroscopy: A pilot study.

OBJECTIVES/HYPOTHESIS: The elastic light single-scattering spectroscopy (ELSSS) system is a new tool for the real-time diagnosis of cancerous lesions. In the current study, we have employed ELSSS to investigate its ability in differentiation between normal and cancerous larynx tissues ex vivo. STUDY DESIGN: Basic science study in assessment of laryngeal malignancy using spectroscopy. METHODS: ELSSS spectra of the larynx tissue were acquired using a single-fiber optical probe. Ex vivo spectroscopic measurements were acquired on 95 laryngeal lesions of 40 patients. Average slopes of the spectra in the wavelength range of 450 to 750 nm were calculated. The signs of the spectral slopes were positive for benign and negative for cancerous larynx tissues. Histopathology results were used as a gold standard to define sensitivity and specificity. RESULTS: The ELSSS system correctly defined 38 out of 41 malignant tissues as cancerous; three of them were misclassified as benign. All benign tissues were correctly classified. Moderate, severely dysplastic, and malignant tissues were correctly classified as cancerous. The system could not classify mild dysplastic tissues either benign or cancerous, whereas nearly half of them were classified as benign and the other half as malignant. The signs of the spectral slopes were used as a discrimination parameter between benign and cancerous (moderate, severely dysplastic, and malignant) lesions with a sensitivity and specificity of 94% and 100%, respectively. CONCLUSIONS: The ELSSS system has the potential to be used as an adjunctive tool in the diagnosis of cancerous laryngeal tissues in real time and noninvasively. This new diagnostic technique may reduce the number of negative biopsies. LEVEL OF EVIDENCE: NA Laryngoscope, 127:611-615, 2017.

Pediatric laryngeal simulator using 3D printed models: A novel technique.

OBJECTIVE: Simulation to acquire and test technical skills is an essential component of medical education and residency training in both surgical and nonsurgical specialties. High-quality simulation education relies on the availability, accessibility, and reliability of models. The objective of this work was to describe a practical pediatric laryngeal model for use in otolaryngology residency training. Ideally, this model would be low-cost, have tactile properties resembling human tissue, and be reliably reproducible. STUDY DESIGN: Pediatric laryngeal models were developed using two manufacturing methods: direct three-dimensional (3D) printing of anatomical models and casted anatomical models using 3D-printed molds. Polylactic acid, acrylonitrile butadiene styrene, and high-impact polystyrene (HIPS) were used for the directly printed models, whereas a silicone elastomer (SE) was used for the casted models. METHODS: The models were evaluated for anatomic quality, ease of manipulation, hardness, and cost of production. A tissue likeness scale was created to validate the simulation model. Fleiss' Kappa rating was performed to evaluate interrater agreement, and analysis of variance was performed to evaluate differences among the materials. RESULTS: The SE provided the most anatomically accurate models, with the tactile properties allowing for surgical manipulation of the larynx. Direct 3D printing was more cost-effective than the SE casting method but did not possess the material properties and tissue likeness necessary for surgical simulation. CONCLUSION: The SE models of the pediatric larynx created from a casting method demonstrated high quality anatomy, tactile properties comparable to human tissue, and easy manipulation with standard surgical instruments. Their use in a reliable, low-cost, accessible, modular simulation system provides a valuable training resource for otolaryngology residents. LEVEL OF EVIDENCE: N/A. Laryngoscope, 127:E132-E137, 2017.

Surgicric 2: A comparative bench study with two established emergency cricothyroidotomy techniques in a porcine model.

BACKGROUND: 'Can't Intubate, Can't Oxygenate' is a rare but life threatening event. Anaesthetists must be trained and have appropriate equipment available for this. The ideal equipment is a topic of ongoing debate. To date cricothyroidotomy training for anaesthetists has concentrated on cannula techniques. However cases reported to the NAP4 audit illustrated that they were associated with a high failure rate. A recent editorial by Kristensen and colleagues suggested all anaesthetists must master a surgical technique. The surgical technique for cricothyroidotomy has been endorsed as the primary technique by the recent Difficult Airway Society 2015 guidelines. METHODS: We conducted a bench study comparing the updated Surgicric 2 device with a scalpel-bougie-tube surgical technique, and the Melker seldinger technique, using a porcine model. Twenty six senior anaesthetists (ST5+) participated. The primary outcome was insertion time. Secondary outcomes included success rate, ease of use, device preference and tracheal trauma. RESULTS: There was a significant difference (P<0.001) in the overall comparisons of the insertion times. The surgical technique had the fastest median time of 62 s. The surgical and Surgicric techniques were significantly faster to perform than the Melker (both P<0.001). The surgical technique had a success rate of 85% at first attempt, and 100% within two attempts, whereas the others had failed attempts. The surgical technique was ranked first by 50% participants and had the lowest grade of posterior tracheal wall trauma, significantly less than the Surgicric 2 (P=0.002). CONCLUSIONS: This study supports training in and the use of surgical cricothyroidotomy by anaesthetists.

Phonomicrosurgery simulation: A low-cost teaching model using easily accessible materials.

OBJECTIVES/HYPOTHESIS: To introduce the use of a new phonomicrosurgical trainer using easily accessible materials, and to establish the effectiveness of the model. STUDY DESIGN: The model uses a grape imbedded in gelatin, a microscope, and microlaryngeal instruments. The study was designed to test baseline differences in training levels, as well as improvement in performance after training with the simulation model. METHODS: Thirty subjects enrolled in the Stanford University School of Medicine otolaryngology training program performed microlaryngeal surgery tasks on a grape. Tasks were designed to model both excision of a vocal fold lesion and vocal fold injection. Anonymized video recordings comparing presimulation and postsimulation training were collected and graded by an expert laryngologist. Both objective comparison of skills and subjective participant surveys were analyzed. RESULTS: Objectively, trainees in all groups made statistically significant improvements across all tested variables, including microscope positioning, creation of a linear incision, elevation of epithelial flaps, excision of a crescent of tissue, vocal fold injection, preservation of remaining tissue, and time to complete all tasks. Subjectively, 100% of participants felt that they had increased comfort with microlaryngeal instruments and decreased intimidation of microlaryngeal surgery after completing the simulation training. This appreciation of skills was most notable and statistically significant in the intern trainees. CONCLUSION: Microlaryngeal surgical simulation is a tool that can be used to train residents to prepare them for phonomicrosurgical procedures at all levels of training. Our low-cost model with accessible materials can be easily duplicated and used to introduce trainees to microlaryngeal surgery or improve skills of more senior trainees. LEVEL OF EVIDENCE: NA Laryngoscope, 126:2528-2533, 2016.

Accuracy assessment and kinematic calibration of the robotic endoscopic microsurgical system.

This paper explores the general stereotactic accuracy of the Robotic Endoscopic Microsurgical System (REMS) by calibrating with a standard optical tracking system. Based on a simple yet effective test protocol, the proposed calibration method combines hand-eye calibration with Bernstein polynomials to improve our kinematic pose accuracy.

Speech-language pathology care and short- and long-term outcomes of laryngeal cancer treatment in the elderly.

OBJECTIVES/HYPOTHESIS: To examine associations between speech-language pathology (SLP) care and pretreatment variables, swallowing and airway impairment, and survival in elderly patients treated for laryngeal cancer. STUDY DESIGN: Retrospective analysis of surveillance, epidemiology, and end results (SEER)-Medicare data. METHODS: We evaluated longitudinal data from 2,370 patients diagnosed with laryngeal cancer from 2004 to 2007 using cross-tabulations, multivariate logistic regression, and survival analysis. RESULTS: Initial treatment with total laryngectomy (odds ratio [OR] = 3.3 [1.6-6.8]), and dysphagia during treatment (OR = 4.0 [2.2-7.2]) were the only significant predictors of SLP care during the initial treatment period. Speech-language pathology care was more likely during the first year (OR = 4.1 [2.7-6.0]) and second year (OR = 1.6 [1.1-2.3]) following initial treatment; however, only 23.7% of patients ever received SLP care. Pretreatment tracheostomy tube placement (OR = 2.8 [1.1-7.0]), initial treatment with total laryngectomy (OR = 3.4 [2.0-5.6]), dysphagia (OR = 7.6 [5.5-10.4]), stricture (OR = 1.9 [1.1-3.1]), interval tracheostomy tube placement (OR = 3.5 [2.4-5.2]), and salvage surgery (OR = 3.1 [1.6-5.8]) were significantly associated with long-term SLP care. After controlling for relevant variables, SLP care was associated with significant relative attenuation of the OR for dysphagia (50%), stricture (26%), weight loss (20%), and pneumonia (21%). Hazards ratio for death, if under SLP care, was 0.83 (0.70-0.99). CONCLUSION: SLP care is underutilized in elderly laryngeal cancer patients and is largely reserved for select patients in anticipation of total laryngectomy or after the onset of impaired airway and swallowing function, but is associated with improved outcomes. These data suggest a need for treatment guidelines that incorporate the routine use of SLP care during the initial treatment period and beyond. LEVEL OF EVIDENCE: 2c.

[Significance of certain experiments relevant to airflow parameters in assessment of voice function].

OBJECTIVE: To investigate the role of airflow parameters of some specific examinations in voice function assessment. METHODS: The s/z ratio, pulmonary function and phonatory aerodynamic parameters were measured in subjects with benign vocal fold lesions and with normal voice. The effect of treatment in subjects with benign vocal fold lesions was evaluated with the phonatory aerodynamic parameters. RESULTS: The value of s/z ratio in the disease group was higher than that in the normal group (P<0.05). The value of PEF was significantly different between the disease group and the normal group for male (P<0.05). MFR, MPT, PTF, SGP, PTP, VE were significantly different between the disease group and the normal group (P<0.05). MFR, MPT, PTF, SGP, PTP of the disease group after surgery for both sex were significantly different from before surgery (P<0.05). The disease group was subdivided into two groups through stroboscopic examination before and one month after surgery: the worse group (with some functional laryngeal abnormality, or organic abnormality except benign vocal fold lesion) and the better group. PTF, PTP, SGP, VE were significantly different between the worse group and the normal voice group. There was almost no significant difference for aerodynamic parameters between the better group and the normal voice group (P>0.05). There was no significant difference between the worse group after 8 weeks'voice training and the normal voice group (P>0.05). CONCLUSIONS: s/z ratio, aerodynamic parameters (MFR, MPT, SGP, PTF, PTP, VE) are valuable for the diagnosis and assessment of the voice disorders. Aerodynamic parameters are sensitive to the change of glottal function during the treatment. Voice training can increase the glottal function of patients after laryngeal microsurgery.

Computed tomographic assessment of the causal factors of unsuccessful medialization thyroplasty.

CONCLUSION: The present results demonstrate that a small implant size, undercorrection of the vocal fold, antero-posterior implant malposition, and the use of expanded polytetrafluoroethylene (ePTFE) are the primary factors that cause a poor outcome of medialization thyroplasty (MT). OBJECTIVES: To assess the postoperative laryngeal condition using computed tomography (CT) in patients with unilateral vocal fold paralysis who underwent MT alone, and to identify the primary causal factors in terms of the surgical procedures that affect the outcomes of MT. METHODS: Twenty-two patients who underwent MT alone were divided into two groups based on either the maximal phonation time or the perceived vocal breathiness. Two laryngologists assessed the postoperative laryngeal CT images during sustained vowel phonation and judged whether there were abnormalities of the arytenoid cartilage position, window position, implant size, and implant position, as well as the degree of correction of the vocal fold. As implant material, a silicone block, ePTFE, and hydroxyapatite had been inserted in 2, 9, and 11 patients, respectively. Comparisons of the prevalence of abnormalities in the abovementioned factors between the different outcomes and between the types of material used for the implant were performed. RESULTS: Twelve patients with a poor outcome and 10 with a good outcome showed 36 and 18 abnormal findings identified by either of the two laryngologists, respectively. In the poor outcome group, a smaller implant size and undercorrection of the vocal fold showed both high kappa values and a significantly higher prevalence than those in the good outcome group (p < 0.001 and p < 0.05), respectively. The comparison between material types demonstrated that the sheet-like material (ePTFE) group exhibited a significantly higher prevalence of undercorrection than the block-like material group (p < 0.05).

Development of a time-dependent numerical model for the assessment of non-stationary pharyngoesophageal tissue vibrations after total laryngectomy.

Laryngeal cancer due to, e.g., extensive smoking and/or alcohol consumption can necessitate the excision of the entire larynx. After such a total laryngectomy, the voice generating structures are lost and with that the quality of life of the concerning patients is drastically reduced. However, the vibrations of the remaining tissue in the so called pharyngoesophageal (PE) segment can be applied as alternative sound generator. Tissue, scar, and geometric aspects of the PE-segment determine the postoperative substitute voice characteristic, being highly important for the future live of the patient. So far, PE-dynamics are simulated by a biomechanical model which is restricted to stationary vibrations, i.e., variations in pitch and amplitude cannot be handled. In order to investigate the dynamical range of PE-vibrations, knowledge about the temporal processes during substitute voice production is of crucial interest. Thus, time-dependent model parameters are suggested in order to quantify non-stationary PE-vibrations and drawing conclusions on the temporal characteristics of tissue stiffness, oscillating mass, pressure, and geometric distributions within the PE-segment. To adapt the numerical model to the PE-vibrations, an automatic, block-based optimization procedure is applied, comprising a combined global and local optimization approach. The suggested optimization procedure is validated with 75 synthetic data sets, simulating non-stationary oscillations of differently shaped PE-segments. The application to four high-speed recordings is shown and discussed. The correlation between model and PE-dynamics is ≥ 97%.

Resource utilization and national demographics of laryngotracheal trauma in children.

IMPORTANCE: Pediatric laryngotracheal trauma is rare but can carry considerable morbidity and health care resource expenditure. However, the true cost of these injuries has not been thoroughly investigated. OBJECTIVE: To use a national administrative pediatric database to identify normative data on pediatric laryngotracheal trauma, specifically with regard to cost and resource utilization. DESIGN AND PARTICIPANTS: Retrospective medical record review using the Kids' Inpatient Database (KID) 2009. Inclusion criteria were admissions with International Classification of Diseases, Ninth Revision, Clinical Modification, codes for fractures or open wounds of the larynx and trachea. MAIN OUTCOMES AND MEASURES: Among many data analyzed were demographic information and admission characteristics, including length of stay, diagnoses, procedures performed, and total charges. RESULTS: There were 106 admissions that met inclusion criteria. Patient mean (SE) age was 15.9 (0.45) years, and 79% were males. The mean (SE) length of stay (LOS) was 8.4 (1.1) days; more than 50% of patients had a LOS longer than 4 days. The mean number of diagnoses per patient was 6.9 (0.6); other traumatic injuries included pneumothorax (n = 18). More than 75% of patients underwent more than 2 procedures during their admission; 60.2% underwent a major operative procedure. The most common procedures performed were laryngoscopy (n = 54) and operative repair of the larynx and/or trachea (n = 32). Tracheostomy was performed in only 30 patients. The mean (SE) total charge was $90,879 ($11,419), and one-third of patients had total charges more than $100,000. CONCLUSIONS AND RELEVANCE: Pediatric laryngotracheal trauma remains a relatively rare clinical entity. These injuries primarily affect older children and are associated with long hospitalizations, multiple procedures, and high resource utilization.

A novel computerized surgeon-machine interface for robot-assisted laser phonomicrosurgery.

OBJECTIVES/HYPOTHESIS: To introduce a novel computerized surgical system for improved usability, intuitiveness, accuracy, and controllability in robot-assisted laser phonomicrosurgery. STUDY DESIGN: Pilot technology assessment. METHODS: The novel system was developed involving a newly designed motorized laser micromanipulator, a touch-screen display, and a graphics stylus. The system allows the control of a CO2 laser through interaction between the stylus and the live video of the surgical area. This empowers the stylus with the ability to have actual effect on the surgical site. Surgical enhancements afforded by this system were established through a pilot technology assessment using randomized trials comparing its performance with a state-of-the-art laser microsurgery system. Resident surgeons and medical students were chosen as subjects in performing sets of trajectory-following exercises. Image processing-based techniques were used for an objective performance assessment. A System Usability Scale-based questionnaire was used for the qualitative assessment. RESULTS: The computerized interface demonstrated superiority in usability, accuracy, and controllability over the state-of-the-art system. Significant ease of use and learning experienced by the subjects were demonstrated by the usability score assigned to the two compared interfaces: computerized interface = 83.96% versus state-of-the-art = 68.02%. The objective analysis showed a significant enhancement in accuracy and controllability: computerized interface = 90.02% versus state-of-the-art = 75.59%. CONCLUSIONS: The novel system significantly enhances the accuracy, usability, and controllability in laser phonomicrosurgery. The design provides an opportunity to improve the ergonomics and safety of current surgical setups.