Double lumen endobronchial tube intubation: lessons learned from anatomy.

BACKGROUND: Double lumen endobronchial tubes (DLTs) are frequently used to employ single lung ventilation strategies during thoracic surgical procedures. Placement of these tubes can be challenging even for experienced clinicians. We hypothesized that airway anatomy, particularly of the glottis and proximal trachea, significantly impacts the ease or difficulty in placement of these tubes. METHODS: Images from 24 randomly selected Positron Emission Tomography - Computed Tomography (PET-CT) scans were evaluated for several anatomic aspects of the upper airway, including size and angulation of the glottis and proximal tracheal using calibrated CT measurements and an online digital protractor. The anatomic issues identified were confirmed in cadaveric anatomic models. RESULTS: Proximal tracheal diameter measurements in PET-CT scans demonstrated a mean ± standard deviation of 20.4 ± 2.5 mm in 12 males and 15.5 ± 0.98 mm in 12 females (p < 0.001), and both were large enough to accommodate 39 French and 37 French DLTs in males and females, respectively. Subsequent measurements of the posterior angulation of the proximal trachea revealed a mean angle of 40.8 ± 5.7 degrees with no sex differences. By combining the 24 individual posterior tracheal angles with the 16 angled distal tip measurements DLTs (mean angle 24.9 ± 2.1 degrees), we created a series of 384 patient intubation angle scenarios. This data clearly showed that DLT rotation to a full 180 degrees decreased the mean intubation angle between the DLT and the proximal trachea from a mean of 66.6 ± 5.9 to only 15.8 ± 5.9 degrees. CONCLUSIONS: Rotation of DLTs a full 180 instead of the recommended 90 degrees facilitates DLT intubations.

Dosimetric comparison between carotid-sparing IMRT and 3DCRT in early glottic cancer patients treated with definitive radiation therapy.

BACKGROUND: The purpose of this study was to evaluate the dosimetric benefits of carotid-sparing IMRT (intensity-modulated radiation therapy) over 3DCRT (three-dimensional conformal radiation therapy) in early glottic cancer patients. MATERIAL AND METHODS: Ten patients with histologically proven early-stage squamous cell cancer of glottis (T1N0), treated with definitive radiotherapy, were selected retrospectively for the dosimetric analysis. Patients were originally treated with 3DCRT technique. For comparison purpose, IMRT plans were generated for each patient. Dosimetric comparison was done between two techniques (IMRT and 3DCRT) in terms of PTV (planning target volume) coverage, HI (homogeneity index), CI (conformity index), and doses to right carotid artery, left carotid artery, and spinal cord. RESULTS: V95% for the PTV was higher in IMRT plans (98.26%) as compared to 3DCRT plans (95.12%) (P-value <0.001), whereas V105% for PTV was significantly higher in 3DCRT plans (16.77%) as compared to IMRT plans (0.32%) (P-value 0.11). In terms of both HI and CI, IMRT plans showed better conformity as compared to 3DCRT plans, with statistically significant difference. Both right and left carotid arteries' average mean and maximum doses were significantly lower in IMRT plans as compared to 3DCRT plans (P-value <0.001). IMRT plans resulted in significant carotid-sparing as compared to 3DCRT plans in terms of V35 and V50 (P-value <0.001). CONCLUSION: Carotid-sparing IMRT resulted in better PTV coverage and lower carotid artery dose as compared to 3DCRT in early glottic cancer patients.

Acoustics and aerodynamic effects following glottal and infraglottal medialization in an excised larynx model.

OBJECTIVE: This study aimed to investigate the impact of the implant's vertical location during Type 1 Thyroplasty (T1T) on acoustics and glottal aerodynamics using excised canine larynx model, providing insights into the optimal technique for treating unilateral vocal fold paralysis (UVFP). METHODS: Measurements were conducted in six excised canine larynges using Silastic implants. Two implant locations, glottal and infraglottal, were tested for each larynx at low and high subglottal pressure levels. Acoustic and intraglottal flow velocity field measurements were taken to assess vocal efficiency (VE), cepstral peak prominence (CPP), and the development of intraglottal vortices. RESULTS: The results indicated that the implant's vertical location significantly influenced vocal efficiency (p = 0.045), with the infraglottal implant generally yielding higher VE values. The effect on CPP was not statistically significant (p = 0.234). Intraglottal velocity field measurements demonstrated larger glottal divergence angles and stronger vortices with the infraglottal implant. CONCLUSION: The findings suggest that medializing the paralyzed fold at the infraglottal level rather than the glottal level can lead to improved vocal efficiency. The observed larger divergence angles and stronger intraglottal vortices with infraglottal medialization may enhance voice outcomes in UVFP patients. These findings have important implications for optimizing T1T procedures and improving voice quality in individuals with UVFP. Further research is warranted to validate these results in clinical settings.

Transoral laser microsurgery for T1 glottic cancer with anterior commissure: Identifying clinical and radiological variables that predict oncological outcome.

PURPOSE: The involvement of the anterior commissure (AC) is regarded to be a risk factor for poor results after transoral laser microsurgery (TLM) for early glottic cancer. The objective of this study was to determine how AC-related clinical and radiological factors affected oncological outcomes in a cohort of patients with T1 stage early glottic carcinoma involving the anterior commissure who were treated with TLM with negative surgical margins. METHODS: Retrospective analysis was performed on clinical, radiological, and follow-up data of patients consecutively treated with TLM at a tertiary academic center between November 2011 and August 2021 for T1 glottic squamous cell carcinoma involving the anterior commissure. Recurrence-free survival (RFS), local control with laser alone (LCL), laryngeal preservation (LP), and overall survival (OS) rates (Kaplan-Meier) were the primary outcome metrics. RESULTS: In our series, 5-year OS probability was 75.1%, RFS was 64.8%, LCL was 73.8%, and LP was 83.4%. OS and RFS were higher in patients with early stages of AC pattern than in patients with advanced stage (p = 0.004, p = 0.034, respectively). Vertical extension ratio was found to be associated with OS and RFS (p = 0.023, p = 0.001, respectively), and thyroid cartilage interlaminar angle with LCL by multiple Cox regression analysis (p = 0.041). CONCLUSION: TLM remains a valuable treatment option for AC involvement. AC3 type involvement and elevated vertical extension ratio were associated with negative prognosis. There have been signs that thyroid cartilage with a narrow angle increases recurrence. Alternative modalities should be kept in mind in the treatment decision of these cases.

Simulation of Multiple Source Vocalization in the Larynx: How True Folds, False Folds, and Aryepiglottic Folds May Interact.

PURPOSE: This study was a modest beginning to determine dominance and entrainment between three soft tissues in the larynx that can be set into flow-induced oscillation and act as sound sources. The hypothesis was that they interact as coupled oscillators with observable bifurcations as energy is exchanged between them. METHODOLOGY: The true vocal folds, the ventricular (false) folds, and the aryepiglottic folds were part of a soft-walled airway that produced airflow for sound production. The methodology was computational, based on a simplified Navier-Stokes solution of convective and compressible airflow in a variable-geometry airway. RESULTS: Three serially connected sources could all produce flow-induced self-oscillation with soft wall tissue and small cross-sectional area. When the glottal cross-sectional areas were similar, bifurcations such as subharmonics, delayed voice onset, and aphonia occurred in the coupled oscillations. CONCLUSIONS: Closely spaced sound sources in the larynx are highly interactive. They appear to entrain to the source that has the combined advantage of small cross-sectional glottal area and proximity to a downstream vocal tract that supports oscillation with acoustic inertance.

Minimal invasive LASER-resection vs. radiotherapy as primary treatment of early glottic cancer. A population-based study with, up to 16 years follow up of survival, rate of laryngectomy and voice function.

BACKGROUND: Early glottic cancer can be treated with laser resection or radiotherapy. In an earlier study, we found that voice function after laser resection was inferior to that after radiotherapy. OBJECTIVES: This study was designed to determine if reduced margins at laser resection improved voice function without impairing oncologic results. METHOD: A total of 268 patients with previously untreated T1-T2 glottic carcinoma were studied. They were primarily treated with either radiotherapy (n = 119) or laser resection (n = 149). Survival, need for additional treatment (radiotherapy and/or total layngectomi) and voice function was compared. RESULT: Median follow up time was 7 years with range 0.5-16.6. There was no difference in the overall survival (p = .065) or disease-specific survival. (p = .126). After radiotherapy 32/119 patients and after laser resection 57/149 patients had recurrence. Total rate of laryngectomy was 24% in the radiotherapy group, and 8% in the laser resection group (p = .001). Voice analysis (T1A) showed more roughness in the radiotherapy group, otherwise no difference. CONCLUSIONS: By reducing the surgical margins, we have achieved a better voice function (T1A) but more patients have needed repeated laser excisions and some have also needed supplementary radiotherapy. The risk of laryngectomy and survival were apparently not affected.

Emotional expressivity in singing. Assessing physiological and acoustic indicators of two opera singers' voice characteristics.

In an earlier study, we analyzed how audio signals obtained from three professional opera singers varied when they sang one octave wide eight-tone scales in ten different emotional colors. The results showed systematic variations in voice source and long-term-average spectrum (LTAS) parameters associated with major emotion "families". For two of the singers, subglottal pressure (PSub) also was recorded, thus allowing analysis of an additional main physiological voice control parameter, glottal resistance (defined as the ratio between PSub and glottal flow), and related to glottal adduction. In the present study, we analyze voice source and LTAS parameters derived from the audio signal and their correlation with Psub and glottal resistance. The measured parameters showed a systematic relationship with the four emotion families observed in our previous study. They also varied systematically with values of the ten emotions along the valence, power, and arousal dimensions; valence showed a significant correlation with the ratio between acoustic voice source energy and subglottal pressure, while Power varied significantly with sound level and two measures related to the spectral dominance of the lowest spectrum partial. the fundamental.

Individualized Dynamic Prediction Model for Patient-Reported Voice Quality in Early-Stage Glottic Cancer.

OBJECTIVE: Early-stage glottic cancer (ESGC) is a malignancy of the head and neck. Besides disease control, preservation and improvement of voice quality are essential. To enable expectation management and well-informed decision-making, patients should be sufficiently counseled with individualized information on expected voice quality. This study aims to develop an individualized dynamic prediction model for patient-reported voice quality. This model should be able to provide individualized predictions at every time point from intake to the end of follow-up. STUDY DESIGN: Longitudinal cohort study. SETTING: Tertiary cancer center. METHODS: Patients treated for ESGC were included in this study (N = 294). The Voice Handicap Index was obtained prospectively. The framework of mixed and joint models was used. The prognostic factors used are treatment, age, gender, comorbidity, performance score, smoking, T-stage, and involvement of the anterior commissure. The overall performance of these models was assessed during an internal cross-validation procedure and presentation of absolute errors using box plots. RESULTS: The mean age in this cohort was 67 years and 81.3% are male. Patients were treated with transoral CO2 laser microsurgery (57.8%), single vocal cord irradiation up to (24.5), or local radiotherapy (17.5%). The mean follow-up was 43.4 months (SD 21.5). Including more measurements during prediction improves predictive performance. Including more clinical and demographic variables did not provide better predictions. Little differences in predictive performance between models were found. CONCLUSION: We developed a dynamic individualized prediction model for patient-reported voice quality. This model has the potential to empower patients and professionals in making well-informed decisions and enables tailor-made counseling.

Profiling the clinical characteristics and surgical efficacy of laryngomalacia in children.

OBJECTIVE: To analyze the clinical characteristics of laryngomalacia in Chinese children and explore the surgical efficacy and factors influencing severe laryngomalacia. METHODS: Children (0-18 years) diagnosed with laryngomalacia in our hospital from January 2016 to January 2022 were enrolled in this study. Clinical data of patients, including general conditions, clinical symptoms, grading and classification, medical comorbidities, surgical efficacy, and the risk factors influencing severe laryngomalacia were retrospectively analyzed. RESULTS: A total of 1810 children were enrolled (male:female; 2.02:1), among which most were infants under 1 year (77.18%). Inspiratory laryngeal stridor (69.56%) was the most common symptom. Most patients had mild laryngomalacia (79.28%), with type IV laryngomalacia being the most common classification (52.27%). Congenital heart disease (37.85%) was the most common medical comorbidity. A total of 168 severe laryngomalacia cases were treated via supraglottoplasty with an effective rate of 83.93%. Notably, preterm birth (OR = 3.868, 95% CI 1.340 ~ 11.168), low birth weight (OR = 4.517, 95% CI 1.477 ~ 13.819) and medical comorbidities (OR = 7.219, 95% CI 2.534 ~ 20.564) were independent risk factors for poor prognosis (P < 0.05). CONCLUSION: Laryngomalacia is common among infants under the age of one, and it is mostly characterized by inspiratory laryngeal stridor with various medical comorbidity. Supraglottoplasty is the first treatment choice for severe laryngomalacia cases with high success rates. However, premature delivery, low birth weight, and medical comorbidities significantly affect the efficacy of surgery.

A case of antenatally undiagnosed laryngeal atresia with tracheo-esophageal fistula with airway obstruction at birth and its management.

Laryngeal atresia is a rare congenital anomaly that is usually diagnosed by antenatal ultrasound, however, if undiagnosed presents with desaturation after birth. A term neonate presented with airway obstruction after birth with multiple failed attempts at intubation and was rescued by proseal laryngeal mask airway (LMA). An esophagoscopy using an Ambuscope utilizing a modified connector assembly revealed an opening on the anterior wall of the esophagus with no esophageal atresia, leading to a diagnosis of H-type tracheo-esophageal fistula (TEF) with laryngeal atresia. The ability to ventilate the neonate via LMA with an absent glottic opening raised the possibility of TEF.

Indirect laryngoscopy is more effective than direct laryngoscopy when tracheal intubation is performed by novice operators: a systematic review, meta-analysis, and trial sequential analysis.

PURPOSE: We sought to perform a systematic review and meta-analysis to determine whether indirect laryngoscopy has an advantage over direct laryngoscopy in terms of the tracheal intubation rate, glottic visualization, and intubation time when used by novice operators. METHODS: We extracted adult prospective randomized trials comparing tracheal intubation with indirect vs direct laryngoscopy in novice operators from electronic databases. We extracted the following data from the identified studies: success rate, glottic visualization, and intubation time. Data from each trial were combined via a random-effects model to calculate the pooled relative risk (RR) or weighted mean difference (WMD) with a 95% confidence interval (CI). We also performed a trial sequential analysis. RESULTS: We included 15 articles (17 trials) comprising 2,290 patients in the systematic review. Compared with the direct laryngoscopy, indirect laryngoscopy improved success rate (RR, 1.15; 95% CI, 1.07 to 1.24; P = 0.0002; I2 = 88%), glottic visualization (RR, 1.76; 95% CI, 1.36 to 2.28; P < 0.001; I2 = 85%), and intubation time (WMD, -9.06 sec; 95% CI, -16.4 to -1.76; P = 0.01; I2 = 98%) in tracheal intubation. Trial sequential analysis showed that the total sample size was sufficient to analyze the success rate and intubation time. CONCLUSION: In this systematic review, we found that the tracheal intubation success rate, glottic visualization, and intubation time were improved when novice operators used indirect laryngoscopy rather than direct laryngoscopy. Trial sequential analysis results indicated that the sample size was sufficient for examining the success rate and intubation time. STUDY REGISTRATION: PROSPERO (CRD42022309045); first registered 4 September 2022.

RéSUMé: OBJECTIF: Nous avons cherché à réaliser une revue systématique et une méta-analyse pour déterminer si la laryngoscopie indirecte présente un avantage par rapport à la laryngoscopie directe en termes de taux de succès d'intubation trachéale, de visualisation glottique et de temps d'intubation lorsqu'elle est utilisée par des opératrices et opérateurs novices. MéTHODE: Nous avons extrait des études randomisées prospectives chez l'adulte comparant l'intubation trachéale avec une laryngoscopie indirecte vs directe réalisée par des opérateurs et opératrices novices à partir de bases de données électroniques. Nous avons extrait les données suivantes des études identifiées : taux de succès, visualisation glottique et temps d'intubation. Les données de chaque étude ont été combinées au moyen d'un modèle à effets aléatoires pour le calcul du risque relatif (RR) groupé ou de la différence moyenne pondérée (DMP) avec un intervalle de confiance (IC) de 95 %. Nous avons également réalisé une analyse séquentielle des études. RéSULTATS: Nous avons inclus 15 articles (17 études) portant sur 2290 patient·es dans notre revue systématique. Par rapport à la laryngoscopie directe, la laryngoscopie indirecte a amélioré le taux de succès (RR, 1,15; IC 95 %, 1,07 à 1,24; P = 0,0002; I2 = 88 %), la visualisation glottique (RR, 1,76; IC 95 %, 1,36 à 2,28; P < 0,001; I2 = 85 %), et le temps d'intubation (DMP, −9,06 s; IC 95 %, −16,4 à −1,76; P = 0,01; I2 = 98 %) pour l'intubation trachéale. L'analyse séquentielle des études a montré que la taille totale de l'échantillon était suffisante pour analyser le taux de succès et le temps d'intubation. CONCLUSION: Dans cette revue systématique, nous avons constaté que le taux de succès de l'intubation trachéale, la visualisation glottique et le temps d'intubation étaient améliorés lorsque les opératrices et opérateurs novices utilisaient la laryngoscopie indirecte plutôt que la laryngoscopie directe. L'analyse séquentielle des études a montré que la taille totale de l'échantillon était suffisante pour analyser le taux de succès et le temps d'intubation. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42022309045); première inscription le 4 septembre 2022.

Quantitative Evaluation of Vocal Bowing Following Bilateral Thyroplasty in Age-Related Vocal Atrophy.

OBJECTIVE: Age-related vocal atrophy (ARVA) is associated with vocal fold bowing, persistent glottal gap during phonation, and dysphonia. Bilateral medialization thyroplasty is sometimes performed in patients with ARVA to improve vocal fold closure and voice. We set out to quantify stroboscopic changes in vocal fold bowing, glottal closure, and abduction angle following bilateral thyroplasty and determine how these changes affect voice quality among patients with ARVA. METHODS: Fifteen individuals with ARVA who underwent bilateral medialization thyroplasty were included in this study. Two independent investigators calculated bowing index (BI), normalized glottal gap area (NGGA), and maximum abduction angle from laryngostroboscopic exams using ImageJ™. Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and patient-reported measures were collected before and after thyroplasty. RESULTS: Thyroplasty resulted in a 10-point improvement in overall CAPE-V (Mean dif -10; 95% CI -17, -3.3, p < 0.01) and VHI-10 (mean dif -3.8; 95% CI -9.8, 2.3, p = 0.19, n = 8). NGGA and BI significantly decreased following surgery (mean dif -78; 95% CI -155, -1.5, p = 0.05; and mean dif -2.1; 95% CI -2.4, -0.84, p < 0.01, respectively). BI correlated with CAPE-V scores (r = 0.66, 95% CI 0.22, 0.87, p < 0.01). When considering the normalized combined contributions of both NGGA and BI, there was a stronger correlation in CAPE-V scores (r = 0.87, 95% CI 0.50, 0.97, p < 0.01) compared with either measure alone. CONCLUSIONS: Thyroplasty resulted in a decrease in vocal fold bowing, glottal gap area, and CAPE-V scores in patients with ARVA. Correction of vocal bowing and glottal gap, following bilateral thyroplasty, improved voice measures following surgery. Quantitative evaluation of vocal fold morphology may be valuable when assessing the severity and treatment-response in patients with ARVA following bilateral thyroplasty. Laryngoscope, 134:835-841, 2024.

Reconstruction of Vocal Fold Medial Surface 3D Trajectories: Effects of Neuromuscular Stimulation and Airflow.

INTRODUCTION: Analysis of medial surface dynamics of the vocal folds (VF) is critical to understanding voice production and treatment of voice disorders. We analyzed VF medial surface vibratory dynamics, evaluating the effects of airflow and nerve stimulation using 3D reconstruction and empirical eigenfunctions (EEF). STUDY DESIGN: In vivo canine hemilarynx phonation. METHODS: An in vivo canine hemilarynx was phonated while graded stimulation of the recurrent and superior laryngeal nerves (RLN and SLN) was performed. For each phonatory condition, vibratory cycles were 3D reconstructed from tattooed landmarks on the VF medial surface at low, medium, and high airflows. Parameters describing medial surface trajectory shape were calculated, and underlying patterns were emphasized using EEFs. Fundamental frequency and smoothed cepstral peak prominence (CPPS) were calculated from acoustic data. RESULTS: Convex-hull area of landmark trajectories increased with increasing flow and decreasing nerve activation level. Trajectory shapes observed included circular, ellipsoid, bent, and figure-eight. They were more circular on the superior and anterior VF, and more elliptical and line-like on the inferior and posterior VF. The EEFs capturing synchronal opening and closing (EEF1) and alternating convergent/divergent (EEF2) glottis shapes were mostly unaffected by flow and nerve stimulation levels. CPPS increased with higher airflow except for low RLN activation and very dominant SLN stimulation. CONCLUSION: We analyzed VF vibration as a function of neuromuscular stimulation and airflow levels. Oscillation patterns such as figure-eight and bent trajectories were linked to high nerve activation and flow. Further studies investigating longer sections of 3D reconstructed oscillations are needed. LEVEL OF EVIDENCE: N/A, Basic Science Laryngoscope, 134:1249-1257, 2024.

3D-4K Exoscope-Assisted CO2 Laser Supraglottoplasty for Severe Laryngomalacia in a Pediatric Patient.

Laryngomalacia is the most frequent congenital laryngeal anomaly. Surgery is possible by means of cold knife, carbon dioxide (CO2 ) laser, microdebrider and coblation, traditionally under microscopic view. We here describe the use of the 3D-4K exoscope assisted CO2 laser supraglottoplasty in tubeless general anesthesia in spontaneous breathing in a 5 month-old patient with severe laryngomalacia. Laryngoscope, 134:1359-1362, 2024.

Histologic Examination of Vocal Fold Mucosal Wave and Vibration.

OBJECTIVES: Despite gross anatomic and histologic differences between human and canine vocal folds, similar wave patterns have been described yet not fully characterized. We reconstructed vocal fold (VF) vibration in a canine hemilarynx and performed histologic examination of the same vocal fold. We demonstrate comparable wave patterns while exploring the importance of certain anatomic architectures. METHODS: An in vivo canine hemilarynx was phonated against a glass prism at low and high muscle activation conditions. Vibration was captured using high-speed video, and trajectories of VF medial surface tattooed landmarks were 3D-reconstructed. The method of empirical eigenfunctions was used to capture the essential dynamics of vibratory movement. Histologic examination of the hemilarynx was performed. RESULTS: Oscillation patterns were highly similar between the in vivo canine and previous reports of ex vivo human models. The two most dominant eigenfunctions comprised over 90% of total variance of movement, representing opening/closing and convergent/divergent movement patterns, respectively. We demonstrate a vertical phase difference during the glottal cycle. The time delay between the inferior and superior VF was greater during opening than closing for both activation conditions. Histological examination of canine VF showed not only a thicker lamina propria layer superiorly but also a distinct pattern of thyroarytenoid muscle fibers and fascicles as described in human studies. CONCLUSIONS: Histologic and vibratory examination of the canine vocal fold demonstrated human vocal fold vibratory patterns despite certain microstructural differences. This study suggests that the multilayered lamina propria may not be fundamental to vibratory patterns necessary for human-like voice production. LEVEL OF EVIDENCE: NA (Basic science study) Laryngoscope, 134:264-271, 2024.

Value and role of surgical margins in transoral laser microsurgery of the larynx, literature review and clinical considerations.

PURPOSE: There is no agreement on the most appropriate post-operative pathway for the management of positive margins after laser cordectomy for early stage glottic tumours (T1-2N0M0). This literature review and meta-analysis aim to evaluate the post-operative treatment with the best oncological results among follow-up, radiotherapy (RT) and surgical second look. The parameters utilized were incidence of recurrence, overall (OS), disease-specific (DSS) and disease-free (DFS) survival and larynx preservation (LP). METHODS: The articles were found through a string typed into PubMed from 2007 to 2022. The studies with detailed oncological results were selected according to inclusion criteria, and then the meta-analysis was carried out. RESULTS: Sixteen studies met the inclusion criteria for 2808 patients. The positive margin was found in 748 patients (26.6%), of which 416 were referred to follow-up, 89 to RT and 242 to a surgical second look. A false positive margin was found in 58/104 patients (56%). The recurrence rate in patients with positive margins was significantly higher (p = 0.003). In OS, DSS, DFS and LP, the odds ratio (OR) value was always greater than 1, assessing the role of the positive margin as a risk factor. CONCLUSIONS: Prospective studies will be necessary to establish the role of positive margin as a prognostic factor. A surgical second look in case of positive margin seems to be the best option for the patient in terms of lower risk of recurrence and better oncological results. Better collaboration between surgeon and pathologist would be desirable to limit the real and false positive margins.

Development and Application of Automated Vocal Fold Tracking Software in a Rat Surgical Model.

OBJECTIVE: The rat is a widely used model for studying vocal fold (VF) function after recurrent laryngeal nerve injury, but common techniques for evaluating rat VF motion remain subjective and imprecise. To address this, we developed a software package, called RatVocalTracker1.0 (RVT1.0), to quantify VF motion and tested it on rats with iatrogenic unilateral vocal fold paralysis (VFP). METHODS: A deep neural network was trained to identify the positions of the VFs and arytenoid cartilages (ACs) in transoral laryngoscope videos of the rat glottis. Software was developed to estimate glottic midline, VF displacement, VF velocity, and AC angle. The software was applied to laryngoscope videos of adult rats before and after right recurrent and superior laryngeal nerve transection (N = 15; 6M, 9F). All software calculated metrics were compared before and after injury and validated against manually calculated metrics. RESULTS: RVT1.0 accurately tracked and quantified VF displacement, VF velocity, and AC angle. Significant differences were found before and after surgery for all RVT1.0 calculated metrics. There was strong agreement between programmatically and manually calculated measures. Automated analysis was also more efficient than nearly all manual methods. CONCLUSION: This approach provides fast, accurate assessment of VF motion in rats with minimal labor and allows for quantitative comparison of lateral differences in movement. Through this novel analysis method, we can differentiate healthy movement from unilateral VFP. RVT1.0 is open-source and will be a valuable tool for researchers using the rat model for laryngology research. LEVEL OF EVIDENCE: NA Laryngoscope, 134:340-346, 2024.

Oncological outcomes and failure patterns of laser cordectomy in recurrent glottic cancer.

PURPOSE: Laser cordectomy is a widely accepted treatment modality for selected cases of early glottic cancers, but its role as a salvage treatment remains unclear. We aimed to investigate the oncological outcomes and failure patterns of salvage cordectomy. MATERIALS AND METHODS: This was a retrospective cohort study of patients who underwent cordectomy for early glottic cancer between 2013 and 2022 at a tertiary referral center. The main outcome measures were overall survival, larynx-preservation rate, tracheostomy dependency rate, and disease-free survival. RESULTS: A total of 142 patients (mean age: 63 years, interquartile range [IQR]: 45-72, 123[86.9 %] males) were analyzed. There were 38 (26.8 %) recurrences after a mean of 22 months (IQR: 17-26). Among them, 25 (17.6 %) underwent salvage cordectomy, while 13 (9.1 %) received other salvage treatments (11[7.7 %] (chemo)radiotherapy and 2[1.4 %] total laryngectomy). In comparison to the other salvage treatments, salvage cordectomy demonstrated lower tracheostomy rates (0 vs. 31 %, p = 0.05), comparable 5-year disease-free survival (62 % vs. 54 %, p = 0.4), higher 5-year larynx preservation rate (92 % vs. 54 %, p = 0.02), and improved 5-year overall survival rate (84 % vs. 62 %, p = 0.01). Factors associated with salvage cordectomy failure were age >60 years (odds ratio [OR]: 1.3, 95 % confidence interval [CI]: 1.15-1.53), smoking continuation (OR: 3.73, 95 % CI: 3.5-4.4), heavy smoking (OR: 1.24, 95 % CI:1.07-2.15), and pT1b + (OR: 2.26, 95 % CI: 2.1-2.9). CONCLUSIONS: Salvage cordectomy offers favorable larynx preservation rates and oncological outcomes for recurrent disease amenable to conservative surgery. Smoking, advanced age, and advanced tumor stages are associated with salvage cordectomy failure.