Faculty Bibliography

OBJECTIVE:Simulation may be a valuable tool in training laryngology office procedures on unsedated patients. However, no studies have examined whether existing awake procedure simulators improve trainee performance in laryngology. Our objective was to evaluate the transfer validity of a previously published 3D-printed laryngeal simulator in improving percutaneous injection laryngoplasty (PIL) competency compared with conventional educational materials with a single-blinded randomized controlled trial. METHODS:Otolaryngology residents with fewer than 10 PIL procedures in their case logs were recruited. A pretraining survey was administered to participants to evaluate baseline procedure-specific knowledge and confidence. The participants underwent block randomization by postgraduate year to receive conventional educational materials either with or without additional training with a 3D-printed laryngeal simulator. Participants performed PIL on an anatomically distinct laryngeal model via trans-thyrohyoid and trans-cricothyroid approaches. Endoscopic and external performance recordings were de-identified and evaluated by two blinded laryngologists using an objective structured assessment of technical skill scale and PIL-specific checklist. RESULTS:Twenty residents completed testing. Baseline characteristics demonstrate no significant differences in confidence level or PIL experience between groups. Senior residents receiving simulator training had significantly better respect for tissue during the trans-thyrohyoid approach compared with control (p < 0.0005). There were no significant differences in performance for junior residents. CONCLUSIONS:In this first transfer validity study of a simulator for office awake procedure in laryngology, we found that a previously described low-cost, high-fidelity 3D-printed PIL simulator improved performance of PIL amongst senior otolaryngology residents, suggesting this accessible model may be a valuable educational adjunct for advanced trainees to practice PIL. LEVEL OF EVIDENCE/METHODS:N/A Laryngoscope, 2023.

3D models of airway lumens were created from CT scans of 19 patients with laryngotracheal stenosis. Computational fluid dynamics (CFD) simulations were completed for each, and results were compared to measured peak inspiratory flow rate, grade of lumen constriction, and measures of airway geometry. Results demonstrate flow resistance and shear stress correlate with degree of lumen constriction and absolute cross-sectional area as well as flow rate. Flow recirculation depends on airway constriction but does not vary with flow rate. Resistance and wall shear stress did not correlate well with functional measures. Flow recirculation did differ between subjects with higher functional measures and subjects with lower functional measures. This analysis provides mathematical models to predict airway resistance, wall shear stress, and flow reversal according lumen constriction and inspiratory flow rate. It suggests aerodynamic factors such as flow recirculation play a role in differences in functional performance between patients with similar airway measures.

OBJECTIVE:To compare outcomes between two standard-of-care anesthesia regimens for operative laryngoscopy: general anesthesia with a neuromuscular blocking agent (NMBA) versus remifentanil and propofol (non-NMBA). METHODS:This was a prospective, single-blinded, randomized controlled trial at a tertiary care center. Patients were randomized to either anesthesia using rocuronium (NMBA) or with remifentanil/propofol infusion alone (non-NMBA). Intraoperative impressions, anesthesia data, and post-operative patient surveys were collected. RESULTS:Sixty-one patients who underwent suspension laryngoscopy from 2020 to 2022 were included (25 female, 36 male, ranging 20-81 years). Thirty patients were enrolled in the NMBA arm and 31 patients in the non-NMBA arm. Heart rate and mean arterial pressure were higher in the NMBA (p < 0.01). Patients in the non-NMBA group were more likely to require vasopressors (p = 0.04, RR = 3.08 [0.86-11.05]). Surgeons were more frequently satisfied with conditions in the NMBA group (86.7%) compared to the non-NMBA group (58.1%, p < 0.01). Procedures were more likely to be paused due to movement in the non-NMBA group (45.1%) compared to the NMBA group (16.6%, p < 0.03, RR = 2.26 [1.02-4.99]). Patients in the non-NMBA group were more likely to endorse myalgia the week after surgery (44%) compared to the NMBA group (8.3%, p < 0.01) and reported higher average pain levels on a 0-10 pain scale (3.7) compared to the paralysis group (2.0). CONCLUSIONS:Anesthesia with rocuronium was associated with better intraoperative conditions and postoperative pain compared to anesthesia with remifentanil/propofol. Remifentanil/propofol were associated with lower blood pressure and suppression of laryngoscopy-associated tachycardia. LEVEL OF EVIDENCE/METHODS:Level 2 Laryngoscope, 2023.

Objective: To compare the effectiveness of disinfection protocols utilizing a ultraviolet (UV) Smart D60 light system with Impeluxâ„¢ technology with a standard Cidex ortho-phthalaldehyde (OPA) disinfection protocol for cleaning flexible fiberoptic laryngoscopes (FFLs). Methods: Two hundred FFLs were tested for bacterial contamination after routine use, and another 200 FFLs were tested after disinfection with one of four methods: enzymatic detergent plus Cidex OPA (standard), enzymatic detergent plus UV Smart D60, microfiber cloth plus UV Smart D60, and nonsterile wipe plus UV Smart D60. Pre- and post-disinfection microbial burden levels and positive culture rates were compared using Kruskal-Wallis ANOVA and Fisher's two-sided exact, respectively. Results: After routine use, approximately 56% (112/200) of FFLs were contaminated, with an average contamination level of 9,973.7 ± 70,136.3 CFU/mL. The standard reprocessing method showed no positive cultures. The enzymatic plus UV, microfiber plus UV, and nonsterile wipe plus UV methods yielded contamination rates of 4% (2/50), 6% (3/50), and 12% (6/50), respectively, with no significant differences among the treatment groups (p > 0.05). The pre-disinfection microbial burden levels decreased significantly after each disinfection technique (p < 0.001). The average microbial burden recovered after enzymatic plus UV, microfiber plus UV, and nonsterile wipe plus UV were 0.40 CFU/mL ± 2, 0.60 CFU/mL ± 2.4, and 12.2 CFU/mL ± 69.5, respectively, with no significant difference among the treatment groups (p > 0.05). Micrococcus species (53.8%) were most frequently isolated, and no high-concern organisms were recovered. Conclusion: Disinfection protocols utilizing UV Smart D60 were as effective as the standard chemical disinfection protocol using Cidex OPA. Level of Evidence: N/A Laryngoscope, 2023.

OBJECTIVE:Objective evaluation of physiological responses using non-invasive methods for the assessment of vocal performance and voice disorders has attracted great interest. This paper, for the first time, aims to implement and evaluate perilaryngeal-cranial functional muscle networks. The study investigates the variations in topographical characteristics of the network and the corresponding ability to differentiate vocal tasks. METHOD/METHODS:Twelve surface electromyography (sEMG) signals were collected bilaterally from six perilaryngeal and cranial muscles. Data were collected from eight subjects (four females) without a known history of voice disorders. The proposed muscle network is composed of pairwise coherence between sEMG recordings. The network metrics include (a) network degree and (b) weighted clustering coefficient (WCC). RESULTS:|=0.12) in differentiating the vocal tasks. CONCLUSION/CONCLUSIONS:Perilaryngeal-cranial functional muscle network was proposed in this paper. The study showed that the functional muscle network could robustly differentiate the vocal tasks while the classic assessment of muscle activation fails to differentiate. SIGNIFICANCE/CONCLUSIONS:For the first time, we demonstrate the power of a perilaryngeal-cranial muscle network as a neurophysiological window to vocal performance. In addition, the study also discovers tasks with the highest network involvement, which may be utilized in the future to monitor voice disorders and rehabilitation.

OBJECTIVES/HYPOTHESIS/OBJECTIVE:We sought to identify changes that occur in spirometric values between surgical interventions in patients with recurrent laryngotracheal stenosis and assess the utility of tracking those changes in predicting the need to return to surgery. METHODS:), peak expiratory flow (PEF), and peak inspiratory flow (PIF), and body mass index (BMI) were tabulated. Calculations were then performed to determine deviations in spirometric measurements from maximums. Comparing the patients who required intervention to those who did not, we used a regression analysis to generate a decision tree based on factors with the strongest predictive power. We then calculated receiver operating characteristic (ROC) curves for all calculated variables. RESULTS:from each patient's maximums had strong predictive power in determining return to surgery. PIF was the only fixed measurement found to have a statistically significant role in predicting return to surgery. BMI did not play a role. CONCLUSION/CONCLUSIONS:For each patient, the deviation from their overall spirometric maximums had the statistically strongest predictive power in determining need to return to surgery. This suggests the importance of the trends in spirometric measures for each individual, and implies these trends have greater import than fixed measures alone. LEVEL OF EVIDENCE/METHODS:IV. Laryngoscope, 2020.

Tracheal stenosis is a health condition in which local narrowing of the upper trachea can cause breathing difficulties and increased incidence of infection, among other symptoms. Occurring most commonly due to intubation of infants, tracheal stenosis often requires corrective surgery. It is challenging to determine the most effective surgical strategy for a given patient as current clinical methods used to assess tracheal stenosis are simplistic and subjective, and are not rigorously based on aerodynamic considerations. This paper summarizes a non-invasive approach based on computational fluid dynamics (CFD) and medical imaging to establish relationships between trachea anatomy and inspiration performance. Though patient-specific CFD analysis has gained recent popularity, an objective of this study is to computationally formulate dimensionless analytical correlations between anatomy and performance that are applicable to any member of a class of patients and that can be interpreted within the context of the Myer-Cotton stenotic airway classification system. These correlations can provide aerodynamics-based insight for the development of more robust stenosis evaluation methods and may allow for time-efficient assessment of corrective surgical strategies.

Conclusion Measurement of the posterior airway space (PAS) using modified barium swallow (MBS) appears to correlate well with CT imaging. This data suggests MBS may be a low-cost alternative imaging modality to assess obstructive sleep apnea patients. Objectives Obstructive sleep apnea research has focused on imaging modalities that supplement polysomnography in evaluation of potential sites of airway obstruction. While several techniques have been used to assess the PAS, many incur significant costs and risks to the patient. This study proposes use of MBS as a simple modality to measure PAS. Advantages include its simplicity, lower radiation, and dynamic tongue base visualization, which may help predict surgical outcomes. It is hypothesized that cephalometric measurements obtained using MBS will correlate well with CT. Methods Thirty-six adult patients who underwent both CT imaging and MBS for head and neck cancer were included. Cephalometric measurements of the PAS were obtained using each imaging modality. Statistical analysis focused on correlating measurements taken using CT and MBS. Results The average PAS measurements were 12.53 ± 1.81 mm and 12.80 ± 1.75 mm by MBS and CT imaging, respectively. In comparing the two modalities, Pearson correlation between CT and MBS measurements revealed significant positive correlations between r = 0.769 and 0.937.