Optical Flow Analysis of Paralaryngeal Muscle Movement.

OBJECTIVES: The paralaryngeal muscles are thought to be hyperfunctional with phonation in patients with primary muscle tension dysphonia (pMTD). However, objective, quantitative tools to assess paralaryngeal movement patterns lack. The objectives of this study were to (1) validate the use of optical flow to characterize paralaryngeal movement patterns with phonation, (2) characterize phonatory optical flow velocities and variability of the paralaryngeal muscles before and after a vocal load challenge, and (3) compare phonatory optical flow measures to standard laryngoscopic, acoustic, and self-perceptual assessments. METHODS: Phonatory movement velocities and variability of the paralaryngeal muscles at vocal onsets and offsets were quantified from ultrasound videos and optical flow methods across 42 subjects with and without a diagnosis of pMTD, before and after a vocal load challenge. Severity of laryngoscopic mediolateral supraglottic compression, acoustic perturbation, and ratings of vocal effort and discomfort were also obtained at both time points. RESULTS: There were no significant differences in optical flow measures of the paralaryngeal muscles with phonation between patients with pMTD and controls. Patients with pMTD had significantly more supraglottic compression, higher acoustic perturbations, and higher vocal effort and vocal tract discomfort ratings. Vocal load had a significant effect on vocal effort and discomfort but not on supraglottic compression, acoustics, or optical flow measures of the paralaryngeal muscles. CONCLUSION: Optical flow methods can be used to study paralaryngeal muscle movement velocity and variability patterns during vocal productions, although the role of the paralaryngeal in pMTD diagnostics (e.g., vocal hyperfunction) remains suspect. LEVEL OF EVIDENCE: 2 Laryngoscope, 134:1792-1801, 2024.

Management of Bilateral Vocal Fold Paralysis: A Systematic Review.

OBJECTIVE: To review the current literature about epidemiology, etiologies and surgical management of bilateral vocal fold paralysis (BVFP). DATA SOURCES: PubMED, Scopus, and Cochrane Library. REVIEW METHODS: A systematic review of the literature on epidemiology, etiologies, and management of adult patients with BVFP was conducted through preferred reporting items for systematic reviews and meta-analyses statements by 2 investigators. RESULTS: Of the 360 identified papers, 245 were screened, and of these 55 were considered for review. The majority (76.6%) of BVFP cases are iatrogenic. BVFP requires immediate tracheotomy in 36.2% of cases. Laterofixation of the vocal fold was described in 9 studies and is a cost-effective alternative procedure to tracheotomy while awaiting potential recovery. Unilateral and bilateral posterior transverse cordotomy outcomes were reported in 9 and 7 studies, respectively. Both approaches are associated with a 95.1% decannulation rate, adequate airway volume, but voice quality worsening. Unilateral/bilateral partial arytenoidectomy data were described in 4 studies, which reported lower decannulation rate (83%) and better voice quality outcome than cordotomy. Revision rates and complications vary across studies, with complications mainly involving edema, granuloma, fibrosis, and scarring. Selective posterior cricoarytenoid reinnervation is being performed by more surgeons and should be a promising addition to the BVFP surgical armamentarium. CONCLUSION: Depending on techniques, the management of BVFP may be associated with several degrees of airway improvements while worsened or unchanged voice quality. The heterogeneity between studies, the lack of large-cohort controlled randomized studies and the confusion with posterior glottic stenosis limit the draw of clear conclusion about the superiority of some techniques over others.

Quantification of False Vocal Fold Hyperfunction During Quiet Breathing in Muscle Tension Dysphonia.

BACKGROUND/OBJECTIVES: False vocal fold (FVF) hyperfunction during phonation is thought to be a diagnostic sign of primary muscle tension dysphonia (pMTD). However, hyperfunctional patterns with phonation are also observed in typical speakers. This study tested the hypothesis that FVF posturing during quiet breathing, as measured by the curvature of FVF, could differentiate patients with pMTD from typical speakers. METHODS: Laryngoscopic images were collected prospectively in 30 subjects with pMTD and 33 typical speakers. Images were acquired at the end of expiration and maximal inspiration during quiet breathing, during sustained /i/, and during loud phonation before and after a 30-min vocal loading task. The FVF curvature (degree of concavity/convexity) was quantified using a novel curvature index (CI, >0 for hyperfunctional/convex, <0 for "relaxed"/concave) and compared between the two groups. RESULTS: At end-expiration, the pMTD group adopted a convex FVF contour, whereas the control group adopted a concave FVF contour (mean CI 0.123 [SEM 0.046] vs. -0.093 [SEM 0.030], p = 0.0002) before vocal loading. At maximal inspiration, the pMTD group had a neutral/straight FVF contour, whereas the control group had a concave FVF contour (mean CI 0.012 [SEM 0.038] vs. -0.155 [SEM 0.018], p = 0.0002). There were no statistically significant differences in FVF curvature between groups in either the sustained voiced or loud conditions. Vocal loading did not change any of these relationships. CONCLUSIONS: A hyperfunctional posture of the FVFs during quiet breathing especially at end-expiration may be more indicative of a hyperfunctional voice disorder than supraglottic constriction during voicing. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3449-3454, 2023.

Interim Results of a Phase 1/2 Open-Label Study of INO-3107 for HPV-6 and/or HPV-11-Associated Recurrent Respiratory Papillomatosis.

OBJECTIVE: To evaluate the safety, immunogenicity, and efficacy of INO-3107, a DNA immunotherapy designed to elicit targeted T-cell responses against human papillomavirus (HPV) types 6 and 11, in adult patients with recurrent respiratory papillomatosis (RRP; NCT04398433). METHODS: Eligible patients required ≥2 surgical interventions for RRP in the year preceding dosing. INO-3107 was administered by intramuscular (IM) injection followed by electroporation (EP) on weeks 0, 3, 6, and 9. Patients underwent surgical debulking within 14 days prior to first dose, with office laryngoscopy and staging at screening and weeks 6, 11, 26, and 52. Primary endpoint was safety and tolerability, as assessed by treatment-emergent adverse events (TEAEs). Secondary endpoints included frequency of surgical interventions post-INO-3107 and cellular immune responses. RESULTS: An initial cohort of 21 patients was enrolled between October 2020 and August 2021. Fifteen (71.4%) patients had ≥1 TEAE; 11 (52.4%) were Grade 1, and 3 (14.3%) were Grade 3 (none treatment related). The most frequently reported TEAE was injection site or procedural pain (n = 8; 38.1%). Sixteen (76.2%) patients had fewer surgical interventions in the year following INO-3107 administration, with a median decrease of 3 interventions versus the preceding year. The RRP severity score, modified by Pransky, showed improvement from baseline to week 52. INO-3107 induced durable cellular responses against HPV-6 and HPV-11, with an increase in activated CD4 and CD8 T cells and CD8 cells with lytic potential. CONCLUSION: The data suggest that INO-3107 administered by IM/EP is tolerable and immunogenic and provides clinical benefit to adults with RRP. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3087-3093, 2023.

Characteristics of Idiopathic Subglottic Stenosis in the Elderly.

OBJECTIVE: To compare characteristics of patients ≥65 years presenting with idiopathic subglottic stenosis (iSGS) to patients diagnosed at <65 years. We hypothesize that the groups have similar comorbidities and disease courses. DATA SOURCES: Medical records of patients treated for iSGS at a tertiary care institution from January 2005-September 2022. REVIEW METHODS: Patient demographics, time from symptom onset to diagnosis, medical history and comorbidities, and treatment modalities/intervals were recorded and analyzed. Characteristics of patients ≥65 and <65 years at presentation were compared using Chi-square analysis for non-numeric values and the Mann-Whitney U-test for numeric values. RESULTS: One hundred seven patients with iSGS were identified and 16 (15%) were aged ≥65 years (mean age 72.6, 15 female) at presentation. These patients were compared to 91 patients aged <65 years (mean age = 47.6, 90 female). Patients ≥65 years had higher rates of type 2 diabetes mellitus (T2DM) (p = 0.004) and tobacco use (p = 0.004). There were no significant differences in body mass index, gastroesophageal reflux disease, hormone replacement therapy, time from symptom onset to presentation, or length of operative treatment intervals. CONCLUSION: Patients ≥65 years with iSGS have higher rates of tobacco use, suggesting that alterations in wound healing may play a role in the development of iSGS in this age group. Although rates of T2DM were higher in the elderly group, clinical significance may be limited given the overall higher rate of diabetes mellitus in the elderly population. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:3075-3079, 2023.

Ultrafast Laser Microlaryngeal Surgery for In Vivo Subepithelial Void Creation in Canine Vocal Folds.

BACKGROUND/OBJECTIVES: Tightly-focused ultrafast laser pulses (pulse widths of 100 fs-10 ps) provide high peak intensities to produce a spatially confined tissue ablation effect. The creation of sub-epithelial voids within scarred vocal folds (VFs) via ultrafast laser ablation may help to localize injectable biomaterials to treat VF scarring. Here, we demonstrate the feasibility of this technique in an animal model using a custom-designed endolaryngeal laser surgery probe. METHODS: Unilateral VF mucosal injuries were created in two canines. Four months later, ultrashort laser pulses (5 ps pulses at 500 kHz) were delivered via the custom laser probe to create sub-epithelial voids of ~3 × 3-mm2 in both healthy and scarred VFs. PEG-rhodamine was injected into these voids. Ex vivo optical imaging and histology were used to assess void morphology and biomaterial localization. RESULTS: Large sub-epithelial voids were observed in both healthy and scarred VFs immediately following in vivo laser treatment. Two-photon imaging and histology confirmed ~3-mm wide subsurface voids in healthy and scarred VFs of canine #2. Biomaterial localization within a void created in the scarred VF of canine #2 was confirmed with fluorescence imaging but was not visualized during follow-up two-photon imaging. As an alternative, the biomaterial was injected into the excised VF and could be observed to localize within the void. CONCLUSIONS: We demonstrated sub-epithelial void formation and the ability to inject biomaterials into voids in a chronic VF scarring model. This proof-of-concept study provides preliminary evidence towards the clinical feasibility of such an approach to treating VF scarring using injectable biomaterials. LEVEL OF EVIDENCES: N/A Laryngoscope, 133:3042-3048, 2023.

Ingredients in the Visual Perception of Hypomobile Vocal Fold Motion Impairment.

OBJECTIVES: The clinical determination of vocal fold (VF) hypomobility based on laryngoscopy is subjective. Previous studies point to VF motion anomaly as the most commonly reported factor in the diagnosis of hypomobility. This study tested the hypotheses that VF angular velocities and angular range of motion (ROM) differ between the two VFs in cases of unilateral VF hypomobility. STUDY DESIGN: Retrospective. METHODS: Semi-automated analysis of laryngoscopic videos of 18 subjects diagnosed with unilateral VF hypomobility and 13 subjects with normal VF mobility was performed to quantify/compare the VF angular velocity and ROM between the two VFs during /i/-sniff and laugh. RESULTS: In the hypomobile VF group, 7 out of 15 (47%) videos with /i/-sniff and 5 out of 8 (63%) with laugh had a statistically significant difference in the angular velocities between the VFs in either abduction or adduction. For VF ROM, 8 out of 15 (53%) /i/-sniff videos and 4 out of 8 (50%) with laughter had a statistically significant difference between VFs. In the group without the diagnosis of VF hypomobility, 9 out of 13 subjects (69%) had no difference in VF angular velocity and ROM during either /i/-sniff or laugh. CONCLUSIONS: Differences in VF angular velocity or ROM are measurable in a substantial subset of subjects diagnosed with unilateral VF hypomobility. Clinicians' ability to gauge VF motion goes beyond what can be extracted from frame-by-frame analysis. Other visual cues, in addition to VF angular velocity and ROM, likely contribute to the perception of unilateral VF hypomobility. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:866-874, 2023.

Association of Genre of Singing and Phonotraumatic Vocal Fold Lesions in Singers.

OBJECTIVES/HYPOTHESIS: To determine if (1) the likelihood of presenting with phonotraumatic lesions differs by singing genre in treatment-seeking singers and (2) if the distribution of phonotraumatic lesion types differs by singing genre. STUDY TYPE: Retrospective. METHODS: Records of singers who presented with a voice complaint over the course of 2.5 years (June 2017-December 2019) were reviewed to determine the proportion of those with phonotraumatic lesions as a function of genre (Study 1). Separately, the lesion types and genres of singers diagnosed with phonotraumatic lesions over a 9-year period (July 2011-March 2020) were determined (Study 2). RESULTS: In Study 1, 191 of 712 (26.8%) dysphonic singers were diagnosed with phonotraumatic lesions. Country/folk, gospel/jazz, and musical theater singers were more likely to present with phonotraumatic lesions. In Study 2, in 443 singers with phonotraumatic lesions, polyps and pseudocysts, but not nodules, were found to be distributed unequally across genres (χ2 p = 0.006, p < 0.0001, p = 0.064, respectively). Praise/worship singers had significantly higher proportions of polyps compared to choral singers (OR 4.8 [95% CI 1.9-12.5]) or compared to musical theater singers (OR 7.2 [95% CI 2.5-20.8]). Opera singers had significantly higher proportions of pseudocysts than choral singers (OR 3.1 [95% CI 1.5-6.1]) or musical theater singers (OR 3.7 [95% CI 1.8-7.6]). CONCLUSIONS: The higher incidence of polyps in praise/worship singers likely reflects the more emphatic nature of singing and the tendency for acute injury. The higher incidence of pseudocysts in opera singers may reflect a more chronic nature of injury. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1683-1689, 2023.

Ultrafast laser surgery probe for sub-surface ablation to enable biomaterial injection in vocal folds.

Creation of sub-epithelial voids within scarred vocal folds via ultrafast laser ablation may help in localization of injectable therapeutic biomaterials towards an improved treatment for vocal fold scarring. Several ultrafast laser surgery probes have been developed for precise ablation of surface tissues; however, these probes lack the tight beam focusing required for sub-surface ablation in highly scattering tissues such as vocal folds. Here, we present a miniaturized ultrafast laser surgery probe designed to perform sub-epithelial ablation in vocal folds. The requirement of high numerical aperture for sub-surface ablation, in addition to the small form factor and side-firing architecture required for clinical use, made for a challenging optical design. An Inhibited Coupling guiding Kagome hollow core photonic crystal fiber delivered micro-Joule level ultrashort pulses from a high repetition rate fiber laser towards a custom-built miniaturized objective, producing a 1/e2 focal beam radius of 1.12 ± 0.10 µm and covering a 46 × 46 µm2 scan area. The probe could deliver up to 3.8 µJ pulses to the tissue surface at 40% transmission efficiency through the entire system, providing significantly higher fluences at the focal plane than were required for sub-epithelial ablation. To assess surgical performance, we performed ablation studies on freshly excised porcine hemi-larynges and found that large area sub-epithelial voids could be created within vocal folds by mechanically translating the probe tip across the tissue surface using external stages. Finally, injection of a model biomaterial into a 1 × 2 mm2 void created 114 ± 30 µm beneath the vocal fold epithelium surface indicated improved localization when compared to direct injection into the tissue without a void, suggesting that our probe may be useful for pre-clinical evaluation of injectable therapeutic biomaterials for vocal fold scarring therapy. With future developments, the surgical system presented here may enable treatment of vocal fold scarring in a clinical setting.

Voice Therapy Expectations for Injured Singers.

OBJECTIVES/HYPOTHESIS: Voice therapy is a mainstay treatment modality in the management of phonotrauma in singers. However, the typical duration of therapy an injured singer undergoes is unknown. The primary aims of the study were to determine (1) the number of therapy sessions preceding a decision for surgery and (2) the number of sessions and length of time to achieve improvement in singers who did not undergo surgery. Whether specific singer factors were associated with the length of therapy was also investigated. STUDY DESIGN: Retrospective. METHODS: Records of singers with phonotraumatic vocal fold lesions seen over a 9-year period at a tertiary care voice center were reviewed. RESULTS: Sixty singers who underwent surgery and 183 singers who did not undergo surgery were included in the final analysis. In nearly ¾ of the surgical patients, five or fewer voice therapy sessions were completed prior to the decision for surgery. Singers who did not undergo surgery required on average 3-4 sessions before noting improvement. Over 60% of the non-surgical singers improved within 3 months and 84% were judged to be improved by 6 months. Lesion type, professional/amateur status, formal voice training, and having a current voice teacher/coach were not associated with the length of voice therapy. CONCLUSIONS: The length of voice therapy prior to decision for surgery was limited, and so was the length of therapy leading to initial improvement in singers who did not require surgery. These findings provide a framework for voice therapy expectations and could be reassuring for this unique population.

Profile of Injured Singers: Expectations and Insights.

OBJECTIVES: To discover patterns of phonotraumatic lesions in singers and investigate factors that differentiate those who underwent surgery from those who did not. We hypothesized that 1) lesion type distribution differs by age, sex, singer classification (professional/amateur), and history of formal voice training; 2) the likelihood of surgery is associated with singer classification and voice training. STUDY DESIGN: Retrospective. METHODS: Retrospective review of 438 singers with phonotraumatic lesions over a 9-year period. Lesion type distribution was analyzed with respect to sex, age, singer classification, and voice training. The association of eventual surgery with these factors was also analyzed. RESULTS: Nodules accounted for over half of the cohort (58%), followed by pseudocysts (20%), polyps (14%), and cysts (4%). Nearly two of every three injured female singers, but fewer than one out of every three injured male singers, had nodules. In contrast, over half of the injured males had polyps, whereas only 6% of injured females had polyps. In females, polyps occurred at a later age, and in males, nodules occurred at a younger age compared to other lesion types. Only 14% of the total cohort eventually underwent surgery. Professional singers without formal voice training were almost eight times more likely to have undergone surgery than amateur singers with voice training. CONCLUSIONS: Professional singers were more likely to undergo surgery than amateurs, and formal voice training was associated with a lower likelihood of surgery. The observation that polyps tended to occur in older women may have implications for the pathogenesis of vocal fold polyps. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:2180-2186, 2022.

Combining Voice Rest and Steroids to Improve Diagnostic Clarity in Phonotraumatic Vocal Fold Injury.

OBJECTIVES: (1) To describe a combination voice rest and steroid regimen to clarify ambiguous diagnoses in singers who present with phonotraumatic lesions and (2) to determine which videostroboscopic parameters show the most consistent response to this regimen. STUDY DESIGN: Chart review. METHODS: Singers with phonotraumatic vocal fold lesions seen at a tertiary care voice center over a 10-year period were identified. Those who had uncertain diagnoses on initial presentation, completed a combination regimen including voice rest and steroids, and had follow-up examinations were included in the analysis. The effect of this combination regimen was assessed by ratings of pre- and postregimen videostroboscopy examinations and by auditory perceptual ratings. Whether the combination regimen clarified the diagnosis was noted. RESULTS: Twenty-nine singers were prescribed the combination regimen with the intent to clarify the diagnosis. In 79% (23/29) of these singers, the regimen helped clarify diagnosis, for example, ruling in or ruling out specific lesions, confirming areas of scar, or distinguishing acute from chronic phonotraumatic injury. Stroboscopic exams were improved in 86% (25/29). The most common stroboscopic finding was a reduction in the lesion size (66%). Auditory perceptual ratings improved in 48% (14/29) of patients. CONCLUSIONS: A "cool down" combination of voice rest and steroids can improve diagnostic clarity in a subset of singers with phonotraumatic lesions. This combination regimen can be considered, with both the side effect profile of steroids and possible financial ramifications of strict voice rest in mind, when the initial diagnosis is unclear.

Patterns of Recurrence of Phonotraumatic Vocal Fold Lesions Suggest Distinct Mechanisms of Injury.

OBJECTIVES/HYPOTHESIS: To examine patterns of recurrence of benign phonotraumatic vocal fold lesions over time for insights into pathophysiology. STUDY DESIGN: Case series with mathematical modeling. METHODS: Medical records and stroboscopic exams of adults who underwent microlaryngoscopic resection of phonotraumatic vocal fold lesions over a 13-year period were reviewed for time to recurrence after surgery. Uniform and log-normal probability distributions were fitted to the time to recurrence curves for vocal fold polyps, midfold masses, and pseudocysts. Model fits were compared using the Akaike information criterion corrected, a standard measure of the goodness of fit. Stochastic simulations were used to verify that the mechanistic hypotheses were concordant with the selected probability distributions and empiric data. RESULTS: Of 567 patients who underwent microlaryngoscopic resection, 65 had a recurrence (16 polyps, 14 midfold masses, and 35 pseudocysts). Midfold mass and pseudocyst recurrences were predominantly seen in younger women. Polyps were best fit by a uniform distribution rather than log-normal, whereas midfold masses and pseudocysts were better fit by log-normal rather than uniform. Stochastic simulations suggest that polyps recur sporadically according to a paroxysmal-developmental model, whereas midfold mass and pseudocyst recurrences follow a force-multiplication, damage-accumulation process. CONCLUSIONS: Vocal fold polyps are acute lesions evenly distributed by age and gender that recur uniformly over time, suggesting they arise from sudden tissue reactions to phonotraumatic stress. Pseudocysts and midfold fibrous masses are chronic lesions predominantly found in young women that recur with log-normal distribution over time, suggesting gradual damage accumulation in larynges predisposed to enhanced phonotrauma. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2523-2529, 2021.

Intraoperative Airway Management Considerations for Adult Patients Presenting With Tracheostomy: A Narrative Review.

Tracheotomy is a surgical procedure through which a tracheostomy, an opening into the trachea, is created. Indications for tracheostomy include facilitation of airway management during prolonged mechanical ventilation, treatment of acute upper airway obstruction when tracheal intubation is unfeasible, management of chronic upper airway obstructive conditions, and planned airway management for major head and neck surgery. Patients who have a recent or long-term tracheostomy may present for a variety of surgical or diagnostic procedures performed under general anesthesia or sedation/analgesia. Airway management of these patients can be challenging and should be planned ahead of time. Anesthesia personnel should be familiar with the different components of cuffed and uncuffed tracheostomy devices and their connectivity to the anesthesia circuits. An appropriate airway management plan should take into account the indication of the tracheostomy, the maturity status of the stoma, the type and size of tracheostomy tube, the expected patient positioning, and presence of patient's concurrent health conditions. Management of the patient with a T-tube is highlighted. Importantly, there is a need for multidisciplinary care involving anesthesiologists, surgical specialists, and perioperative nurses. The aim of this narrative review is to discuss the anesthesia care of patients with a tracheostomy. Key aspects on relevant tracheal anatomy, tracheostomy tubes/devices, alternatives of airway management, and possible complications related to tracheostomy are summarized with a recommendation for an algorithm to manage intraoperative tracheostomy tube dislodgement.

Vocal Tradeoffs in Anterior Glottoplasty for Voice Feminization.

OBJECTIVES/HYPOTHESIS: Anterior (Wendler) glottoplasty has become a popular surgery for voice feminization. However, there has been some discrepancy between its theoretical pitch-raising potential and what is actually achievable, and downsides to shortening the glottis have not been fully explored. In addition, descriptions of the surgery are inconsistent in their treatment of the vocal ligament. This study aimed to determine 1) how fundamental frequency (fo ) is expected to vary with length of anterior glottic fixation, 2) the impact of glottic shortening on sound pressure level (SPL), and 3) the effect of including the ligament in fixation. STUDY DESIGN: Computational simulation. METHODS: Voice production was simulated in a fiber-gel finite element computational model using canonical male vocal fold geometry incorporating a three-layer vocal fold composition (superficial lamina propria, vocal ligament, and thyroarytenoid muscle). Progressive anterior glottic fixation (0, 1/8, 2/8, 3/8, etc. up to 7/8 of membranous vocal fold length) was simulated. Outcome measures were fo , SPL, and glottal flow waveforms. RESULTS: fo increased from 110 Hz to 164 Hz when the anterior one-half vocal fold was fixed and continued to progressively rise with further fixation. SPL progressively decreased beyond 1/8 to 1/4 fixation. Inclusion of the vocal ligament in fixation did not further increase fo . Any fixation increased aperiodicity in the acoustic signal. CONCLUSIONS: The optimal length of fixation is a compromise between pitch elevation and reduction in output acoustic power. The simulation also provided a potential explanation for vocal roughness that is sometimes noted after anterior glottoplasty. LEVEL OF EVIDENCE: NA Laryngoscope, 131:1081-1087, 2021.

Impact of Patient Factors and Management Strategies on Outcomes After Transverse Posterior Cordotomy.

OBJECTIVES/HYPOTHESIS: Carbon dioxide laser transverse posterior cordotomy (TPC) aims to improve airway aperture in patients with glottic obstruction. Postoperative complications may worsen airway compromise and necessitate additional interventions. We sought to identify factors impacting outcomes after TPC. STUDY DESIGN: Retrospective chart review. METHODS: Medical records of patients who underwent TPC for glottic airway obstruction at a tertiary-care medical center between 2008 and 2018 were reviewed. Demographics, comorbidities, and intra- and postoperative management strategies were analyzed. RESULTS: Twenty patients who underwent TPC for glottic airway obstruction met inclusion criteria. The mean age was 57 years, and 13 patients were female. Mean follow-up time was 442 days. Seven patients had posterior glottic stenosis, and 13 had bilateral vocal fold paralysis. Twelve patients developed postoperative complications including granuloma formation (four patients), hospital readmission for dyspnea due to glottic edema (five patients), need for revision surgery (nine patients), or failure to decannulate tracheotomy (five patients). Eight patients had an uncomplicated recovery with improved dyspnea, with two patients with tracheotomies decannulated. Patients with a history of smoking tobacco were more likely to experience complications (P = .035). There were no significant differences in outcomes with respect to history of head and neck radiation or gastroesophageal reflux disease. Steroid injection at the surgical site and postoperative medications did not significantly impact outcomes. With respect to granuloma formation, none of the variables analyzed reached significance. CONCLUSIONS: History of tobacco use increases complication rates after TPC. Other patient comorbidities and intra- and postoperative management strategies do not impact outcomes. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1066-1070, 2021.

Scattering properties and femtosecond laser ablation thresholds of human and canine vocal folds at 776-nm wavelength.

Ultrafast laser ablation may provide a treatment for vocal fold (VF) scarring. Optical properties of VFs must be known prior to clinical implementation to select appropriate laser surgery conditions. We present scattering lengths of epithelium ℓs , ep, superficial lamina propria ℓs , SLP, and ablation thresholds Fth of human and canine VF tissues. Our experimental approach involves an image-guided, laser-ablation-based method that allows for simultaneous determination of ℓs and Fth in these multilayered tissues. Studying eight canine samples, we found ℓs , ep = 75.3 ± 5.7 µm, ℓs , SLP = 26.1 ± 1.2 µm, Fth , ep = 1.58 ± 0.06 J / cm2, and Fth , SLP = 1.55 ± 0.17 J / cm2. Studying five human samples, we found ℓs , ep = 42.8 ± 3.3 µm and Fth , ep = 1.66 ± 0.10 J / cm2. We studied the effects of cumulative pulse overlap on ablation threshold and found no significant variations beyond 12 overlapping pulses. Interestingly, our studies about the effect of sample storage on the scattering properties of porcine VF show a 60% increase in ℓs , ep for fresh porcine VF when compared to the same sample stored in isotonic solution. These results provide guidelines for clinical implementation by enabling selection of optimal laser surgery parameters for subsurface ablation of VF tissues.

Reducing sedation time for thyroplasty with arytenoid adduction with sequential anesthetic technique.

OBJECTIVE: To determine the extent to which a sequential anesthetic technique 1) shortens time under sedation for thyroplasty with arytenoid adduction (TP-AA), 2) affects the total operative time, and 3) changes the voice outcome compared to TP-AA performed entirely under sedation/analgesia. STUDY DESIGN: Case-control study. METHODS: A new sequential anesthetic technique of performing most of the TP-AA surgery under general anesthesia (GA), followed by transition to sedation/analgesia (SA) for voice assessment, was developed to achieve smooth emergence from GA. Twenty-five TP-AA cases performed with the sequential GA-SA technique were compared with 25 TP-AA controls performed completely under sedation/analgesia. The primary outcome measure was the time under sedation. Voice improvement, as assessed by Consensus Auditory-Perceptual Evaluation of Voice, and total operative time were secondary outcome measures. RESULTS: With the conventional all-SA anesthetic, the duration of SA was 209 ± 26.3 minutes. With the sequential GA-SA technique, the duration of SA was 79.0 ± 18.9 minutes, a 62.3% reduction (P < 0.0001). There was no significant difference in the total operative time (209.5 vs. 200.9 minutes; P = 0.42) or in voice outcome. This sequential anesthetic technique has been easily adopted by multiple anesthesiologists and nurse anesthetists at our institution. CONCLUSION: TP-AA is effectively performed under sequential GA-SA technique with a significant reduction in the duration of time under sedation. This allows the surgeon to perform the technically more challenging part of the surgery under GA, without having to contend with variability in patient tolerance for laryngeal manipulation under sedation. LEVEL OF EVIDENCE: 3b. Laryngoscope, 127:2813-2817, 2017.

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation.

OBJECTIVES/HYPOTHESIS: Patients with unilateral vocal fold paralysis (UVFP) are commonly told to wait 12 months for spontaneous recovery. This study aims to 1) determine the time to vocal recovery in UVFP, 2) use that data to develop a neurophysiologically plausible model for recovery, and 3) use the model to generate meaningful predictions for patient counseling. STUDY DESIGN: Case series with de novo mathematical modeling. METHODS: Patients with UVFP who could pinpoint a discrete onset of vocal improvement were identified. The time-to-recovery data were modeled by assuming an "early" recovery group with neuropraxia and a "late" recovery group with more severe nerve injury. For the late group, a two-stage model was developed to explain the time to recovery: regenerating axons must cross the site of injury in stage 1 (probabilistic), followed by unimpeded regrowth to the larynx in stage 2 (deterministic). RESULTS: Of 727 cases of UVFP over a 7-year period, 44 reported spontaneous recovery with a discrete onset of vocal improvement. A hybrid distribution incorporating the two stages (exponentially modified Gaussian) accurately modeled the time-to-recovery data (R2 = 0.918). The model predicts 86% of patients with recoverable UVFP will recover within 6 months, with 96% recovering within 9 months. Earlier vocal recovery is associated with recovery of vocal fold motion and younger age. CONCLUSIONS: Waiting 12 months for spontaneous recovery is probably too conservative. Repair across the site of injury, and not regrowth to larynx, is likely the rate-determining step in reinnervation, consistent with other works on peripheral nerve regeneration. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2585-2590, 2017.

Factors Influencing Likelihood of Voice Therapy Attendance.

Objective To identify factors associated with the likelihood of attending voice therapy among patients referred for it in the CHEER (Creating Healthcare Excellence through Education and Research) practice-based research network infrastructure. Study Design Prospectively enrolled cross-sectional study. Setting CHEER network of community and academic sites. Methods Data were collected on patient-reported demographics, voice-related diagnoses, voice-related handicap (Voice Handicap Index-10), likelihood of attending voice therapy (VT), and opinions on factors influencing likelihood of attending VT. The relationships between patient characteristics/opinions and likelihood of attending VT were investigated. Results A total of 170 patients with various voice-related diagnoses reported receiving a recommendation for VT. Of those, 85% indicated that they were likely to attend it, regardless of voice-related handicap severity. The most common factors influencing likelihood of VT attendance were insurance/copay, relief that it was not cancer, and travel. Those who were not likely to attend VT identified, as important factors, unclear potential improvement, not understanding the purpose of therapy, and concern that it would be too hard. In multivariate analysis, factors associated with greater likelihood of attending VT included shorter travel distance, age (40-59 years), and being seen in an academic practice. Conclusions Most patients reported plans to attend VT as recommended. Patients who intended to attend VT reported different considerations in their decision making from those who did not plan to attend. These findings may inform patient counseling and efforts to increase access to voice care.