Effect of Electrode Configuration and Impulse Strength on Airway Patency in Neurostimulation for Obstructive Sleep Apnea.

OBJECTIVES/HYPOTHESIS: Hypoglossal nerve stimulation (HNS) has gained increasing interest for the treatment of patients with obstructive sleep apnea (OSA). Drug-induced sleep endoscopy (DISE) can both exclude improper airway collapse patterns and visualize airway changes under stimulation. Stimulation outcome effects depend on the impulse voltage and electric field resulting from the electrode configuration of the implanted device. The effects of various combinations of voltage and electric field on DISE airway patterns in contrast to awake endoscopy are unknown. STUDY DESIGN: Cohort study. METHODS: During therapy adjustment about 6 months after implantation, patients underwent a DISE and awake endoscopy with 100% and 125% of functional voltage in three typical electrode configurations (+ - +, o - o, - - -). All videos were analyzed by two separate persons for the opening of the airway at velum, tongue base, and epiglottis level. RESULTS: Thirty patients showed typical demographic data. The opening effects were visible in all patients, but there were changes between different electrode configurations. Several demographic or therapeutic aspects such as obesity, OSA severity, or prior soft palate surgery were associated with changes arising from different electrode configurations, but none resulted in a consistently better airway opening. CONCLUSIONS: In patients with poor results during the therapy adjustment, electric configuration changes can improve airway patency-an independent variable from increasing voltage. As these effects can only be seen in awake endoscopy or DISE, both endoscopies with live stimulation may be considered in cases with insufficient improvement in apnea-hypopnea index after initiation of HNS therapy. LEVEL OF EVIDENCE: Prospective case series; level 4. Laryngoscope, 131:2148-2153, 2021.

Neonatal Lateral Epiglottic Defects.

INTRODUCTION: Multiple congenital abnormalities of the epiglottis have been reported and iatrogenic injuries to the larynx and subglottis are well known. We present a new pattern of defect not previously reported in the literature. METHODS: Epiglottic abnormalities at two institutions are reviewed. Cases of defects involving the lateral aspect of the epiglottis and aryepiglottic fold are identified. A literature review of known epiglottic defects is performed. RESULTS: Two children possessing lateral notch injuries at the aryepiglottic attachment to the epiglottis are described. Both children have a history of multiple laryngeal instrumentation attempts and prolonged intubation. Both have swallowing difficulties and are gastrostomy dependent. Congenital epiglottic defects include aplasia and midline bifidity, however, no lateral congenital epiglottic defects have been reported. CONCLUSION: Epiglottic defects, while rare, should be part of the differential for children with aspiration and feeding difficulties. A new pattern of defect is described and iatrogenic etiology proposed.

Floppy epiglottis during drug-induced sleep endoscopy: an almost complete resolution by adopting the lateral posture.

PURPOSE: To analyze the presence of a floppy epiglottis (FE) during drug-induced sleep endoscopy in non-apneic snoring patients, non-positional obstructive sleep apnea (OSA) patients (NPP), and position-dependent OSA patients (PP) and to evaluate the impact of maneuvers and body position during drug-induced sleep endoscopy, including jaw thrust and supine and lateral head (and trunk) position. METHODS: Retrospective cohort study. RESULTS: In total, 324 patients were included. In 60 patients (18.5%), a FE was found in supine position: seven non-apneic snoring patients and 53 OSA patients. When performing lateral head rotation only, a FE was present in four patients (NPP, N = 0; PP, N = 4). When patients were tilted to both lateral head and trunk position, a FE was found in only one subject. After applying jaw thrust, a FE was still present in 10 patients. The prevalence of a FE did not differ between NPP and PP. When comparing baseline characteristics between patients with and without a FE in supine position, no significant differences were found. CONCLUSION: A FE appears almost exclusively in supine position. In patients with a FE, positional therapy can be a promising alternative as a standalone treatment, but also as part of combination therapy with for example mandibular advancement devices or less invasive forms of upper airway surgery.

The clinical characteristics of patients with an isolate epiglottic collapse.

OBJECTIVE: We analyzed the clinical characteristics of patients with isolated epiglottic collapse (IEC) who had an epiglottic anteroposterior (AP) collapse as the only cause of snoring during drug-induced sleep endoscopy (DISE). METHODS: A retrospective analysis of 334 consecutive DISE examinations was performed. Patients who had only epiglottic AP collapse were designated as the IEC group. There were four age- and sex-matched controls for each case, and these patients were designated as the control group. Demographic factors, polysomnography findings, cephalometry, and awake nasopharyngoscopic findings were analyzed. RESULTS: A total of 11 IEC cases and 44 controls were included. The IEC group had a significantly lower apnea-hypopnea index, higher minimum oxygen saturation level, lower body mass index, and shorter mandible plane to hyoid distance than the controls. However, there were no differences in epiglottic shape or curvature between the two groups. In addition, no IEC was noted during awake endoscopy. Nine (81.8%) epiglottic collapses were resolved with the mouth open and jaw thrust maneuver, which simulated the use of an oral appliance. Six (54.4%) were resolved with head turning, mimicking the lateral sleep position. CONCLUSION: The clinical characteristics of IEC patients differed from the control group, and IEC could not be identified during awake endoscopy. Therefore, patients with severe snoring but AHI < 5 or mild sleep apnea on polysomnographic findings and DISE, should be considered likely to have IEC. In addition, use of an oral appliance is recommended as an effective treatment for IEC.

Adenoma pleomorfo de epiglotis / Pleomorphic adenoma of the epiglottis

No disponible

Comparison of Pharyngeal Airway between Mandibular Setback Surgery Patients (Skeletal Class III) and Nonsurgery Patients (Skeletal Classes I and II).

PURPOSE: We investigated the pharyngeal airway dimensions and their correlations in patients who underwent mandibular setback surgery versus those who did not. MATERIALS AND METHODS: One hundred and sixty cephalometric radiographs (120 patients) were obtained from patients with three skeletal malocclusion classifications: Class I and Class II in the nonsurgery group and Class III in the surgery group (preoperative and postoperative cephalograms). The following dimensions were measured: nasopharyngeal airway (NOP), uvulopharyngeal airway (UOP), shortest distance from the posterior tongue to the pharyngeal wall (TOP), and distance from the epiglottis to the pharyngeal wall (EOP). Paired t test, one-way analysis of variance, and Pearson correlation coefficients were used for statistical analysis. RESULTS: Preoperatively, UOP and TOP of skeletal Class III patients (15.2 mm and 16.6 mm) were significantly larger than those of skeletal Class II (11.5 mm and 12 mm) and Class II (12.3 mm and 12.9 mm) patients, respectively. No differences were observed in EOP between the three skeletal patterns. The hyoid bone of Class III patients was significantly anterior to that of Class I/II patients. Furthermore, UOP had a moderate negative correlation with soft palate length. Postoperatively, no significant difference (UOP, TOP, EOP, soft palate width, and hyoid bone) was found between the skeletal classes. CONCLUSION: Preoperatively, UOP and TOP of skeletal Class III patients were significantly wider than those of skeletal Class I/II patients. Pre- and postoperatively, EOP did not exhibit significant differences among the three skeletal classifications. No differences were found in all postoperative pharyngeal airway dimensions between Class III patients and nonsurgery patients (Class I and Class II).

Is epiglottis surgery necessary for obstructive sleep apnea patients with epiglottis obstruction?

OBJECTIVES/HYPOTHESIS: To examine the effect of epiglottis obstruction during drug-induced sleep endoscopy (DISE) on the surgical results of multilevel sleep surgery without epiglottic intervention. STUDY DESIGN: Cross-sectional study. METHODS: This investigation involved patients diagnosed with severe obstructive sleep apnea (OSA) based on preoperative polysomnography (PSG), who underwent DISE followed by multilevel OSA surgery without epiglottic intervention at Kyung Hee Medical Center (Seoul, South Korea) between March 2013 and July 2016. During DISE, obstruction patterns of the upper airway were evaluated using the velum, oropharynx, tongue base, epiglottis classification method. Follow-up PSG was performed 3 months after surgery to determine the success rate of multilevel surgery without epiglottic intervention. A comparison was done between the group with epiglottis obstruction and the group without epiglottis obstruction. RESULTS: Epiglottis obstruction was observed during DISE in 43.7% of patients. After application of exclusion criteria, 54 subjects were included (27 with and 27 without epiglottis obstruction). DISE revealed an association between epiglottis obstruction and tongue base collapse (P = .02). Comparing pre- and postoperative PSG findings, both groups exhibited improvement postoperatively. The success rate was 44.4% in the epiglottis obstruction group and 40.7% in the non-epiglottis obstruction group (P = .80). There was no difference in surgical success rates between the two groups. CONCLUSIONS: The prevalence of epiglottis obstruction requiring epiglottic surgery was lower than what was found during DISE. Sleep surgeons may consider staged epiglottic surgery in patients with epiglottis obstruction. LEVEL OF EVIDENCE: 3b Laryngoscope, 129:2658-2662, 2019.

Acoustic Characteristics in Epiglottic Cyst.

OBJECTIVE: The purpose of this study was to analyze the acoustic characteristics associated with alternation deformation of the vocal tract due to large epiglottic cyst, and to confirm the relation between the anatomical change and resonant function of the vocal tract. METHODS: Eight men with epiglottic cyst were enrolled in this study. The jitter, shimmer, noise-to-harmonic ratio, and first two formants were analyzed in vowels /a:/, /e:/, /i:/, /o:/, and /u:/. These values were analyzed before and after laryngeal microsurgery. RESULTS: The F1 value of /a:/ was significantly raised after surgery. Significant differences of formant frequencies in other vowels, jitter, shimmer, and noise-to-harmonic ratio were not presented. CONCLUSION: The results of this study could be used to analyze changes in the resonance of vocal tracts due to the epiglottic cysts.

Surgical Intervention for Exercise-Induced Laryngeal Obstruction.

Respiratory distress during exercise can be caused by exercise-induced laryngeal obstruction (EILO). The obstruction may appear at the level of the laryngeal inlet (supraglottic), similar to supraglottic collapse observed in infants with congenital laryngomalacia (CLM). This observation has encouraged surgeons to treat supraglottic EILO with procedures proven efficient for severe CLM. This article summarizes key features of the published experience related to surgical treatment of EILO. Supraglottoplasty is an irreversible procedure with potential complications. Surgery should be restricted to cases where the supraglottic laryngeal obstruction significantly affects the quality of life in patients for whom conservative treatment modalities have failed.

Interobserver Consistency of Drug-Induced Sleep Endoscopy in Diagnosing Obstructive Sleep Apnea Using a VOTE Classification System.

OBJECTIVES: To explore the interobserver consistency of drug-induced sleep endoscopy (DISE) for patients with obstructive sleep apnea syndrome (OSAS) and review the current literature. METHODS: In total, 55 patients with an apnea-hypopnea index >5, as determined by on overnight sleep study, were included in this study, 45 males and 10 females, with an average age of 46.87 ±â€Š10.06 years old (range, 19-71). For all OSAS patients, DISE was performed by the same surgeon, which was recorded digitally. The video recordings of DISE were evaluated independently by 3 experienced surgeons who were asked to note his or her decisions as the pattern, site, and degree of upper airway collapse using a VOTE (velum, oropharynx lateral wall, tongue base, and the epiglottis) classification system. RESULTS: Interobserver consistency in the diagnosis of velum-related obstruction in anteroposterior, lateral, and concentric configurations ranged from poor to good. Only significant interobserver consistency among observers A and B was obtained in the diagnosis of oropharynx-related obstruction in the lateral configuration (concordance 60.0%, kappa: 0.365, P < 0.05). Interobserver consistency in the diagnosis of the tongue-related collapse in an anteroposterior configuration, the epiglottis-related collapse in an anteroposterior and lateral configuration ranged from fair to moderate (all kappa values >0.20, all P values < 0.05). CONCLUSION: Our data suggested that the interobserver consistency of DISE ranged from poor to good. Therefore, further studies with larger numbers of patients are needed to standardize DISE procedures, training, and interpretation.

Predicting epiglottic collapse in patients with obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is characterised by pharyngeal obstruction occurring at different sites. Endoscopic studies reveal that epiglottic collapse renders patients at higher risk of failed oral appliance therapy or accentuated collapse on continuous positive airway pressure. Diagnosing epiglottic collapse currently requires invasive studies (imaging and endoscopy). As an alternative, we propose that epiglottic collapse can be detected from the distinct airflow patterns it produces during sleep.23 OSA patients underwent natural sleep endoscopy. 1232 breaths were scored as epiglottic/nonepiglottic collapse. Several flow characteristics were determined from the flow signal (recorded simultaneously with endoscopy) and used to build a predictive model to distinguish epiglottic from nonepiglottic collapse. Additionally, 10 OSA patients were studied to validate the pneumotachograph flow features using nasal pressure signals.Epiglottic collapse was characterised by a rapid fall(s) in the inspiratory flow, more variable inspiratory and expiratory flow and reduced tidal volume. The cross-validated accuracy was 84%. Predictive features obtained from pneumotachograph flow and nasal pressure were strongly correlated.This study demonstrates that epiglottic collapse can be identified from the airflow signal measured during a sleep study. This method may enable clinicians to use clinically collected data to characterise underlying physiology and improve treatment decisions.

Glottis effects on the cough clearance process simulated with a CFD dynamic mesh and Eulerian wall film model.

In this study, we have reproduced the cough clearance process with an Eulerian wall film model. The simulated domain is based on realistic geometry from the literature, which has been improved by adding the glottis and epiglottis. The vocal fold movement has been included due to the dynamic mesh method, considering different abduction and adduction angles and velocities. The proposed methodology captures the deformation of the flexible tissue, considers non-Newtonian properties for the mucus, and enables us to reproduce a single cough or a cough epoch. The cough efficiency (CE) has been used to quantify the overall performance of the cough, considering many different boundary conditions, for the analysis of the glottis effect. It was observed that a viscous shear force is the main mechanism in the cough clearance process, while the glottis closure time and the epiglottis position do not have a significant effect on the CE. The cough assistance devices improve the CE, and the enhancement rate grows logarithmically with the operating pressure. The cough can achieve an effective mucus clearance process, even with a fixed glottis. Nevertheless, the glottis closure substantially improves the CE results.

Airflow Shape Is Associated With the Pharyngeal Structure Causing OSA.

BACKGROUND: OSA results from the collapse of different pharyngeal structures (soft palate, tongue, lateral walls, and epiglottis). The structure involved in collapse has been shown to impact non-CPAP OSA treatment. Different inspiratory airflow shapes are also observed among patients with OSA. We hypothesized that inspiratory flow shape reflects the underlying pharyngeal structure involved in airway collapse. METHODS: Subjects with OSA were studied with a pediatric endoscope and simultaneous nasal flow and pharyngeal pressure recordings during natural sleep. The mechanism causing collapse was classified as tongue-related, isolated palatal, lateral walls, or epiglottis. Flow shape was classified according to the degree of negative effort dependence (NED), defined as the percent reduction in inspiratory flow from peak to plateau. RESULTS: Thirty-one subjects with OSA (mean apnea-hypopnea index score ± SD, 54 ± 27 events/h) who were 50 ± 9 years of age were studied. NED was associated with the structure causing collapse (P < .001). Tongue-related obstruction (n = 13) was associated with a small amount of NED (median, 19; interquartile range [IQR], 14%-25%). Moderate NED was found among subjects with isolated palatal collapse (median, 45; IQR, 39%-52%; n = 8) and lateral wall collapse (median, 50; IQR, 44%-64%; n = 8). The epiglottis was associated with severe NED (median, 89; IQR, 78%-91%) and abrupt discontinuities in inspiratory flow (n = 9). CONCLUSIONS: Inspiratory flow shape is influenced by the pharyngeal structure causing collapse. Flow shape analysis may be used as a noninvasive tool to help determine the pharyngeal structure causing collapse.

Effect of physical stress on drug-induced sleep endoscopy for obstructive sleep apnea.

Drug-induced sleep endoscopy (DISE) is a reliable upper airway evaluation tool, widely used to improve surgical results in patients with obstructive sleep apnea (OSA). Several factors, including sleeping position and depth of sedation, affect DISE findings. This study aimed to evaluate the impact of physical stress on DISE findings. Eighty-five patients with OSA underwent two DISE examinations at the same level of sedation. The "first DISE" (control group) was performed after polysomnography, while the "second DISE" (test group) performed immediately after a treadmill stress test. The two groups were compared for changes in degree and configuration of airway obstruction at the levels of the velum, oropharynx, tongue base, and epiglottis. There were several differences in DISE findings between the control and test groups. DISE findings obtained after the stress test revealed significant narrowing of multiple airway structures; upper airway narrowing was observed at the velum (19/48; 39.6%), oropharynx (31/63; 49.2%), and tongue base (9/61; 14.8%). Changes in configuration of upper airway obstruction were observed only at the level of the velum (33/85; 38.8%). Stress exercise test induces changes in the degree and configuration of upper airways narrowing, which causes surgeons to over or underestimate the obstructive pattern, depending on the clinical circumstance. When counseling patients on the likely value of sleep surgery based on DISE findings, stressful physical activity should be included as a contributing factor in treatment planning.

Quantification of rat supraglottic laryngeal sensation threshold.

OBJECTIVE: Laryngeal adductor response (LAR) to air puff is used as a reliable method in evaluating sensation thresholds (ST) in human laryngeal sensory disorders. This method has been difficult to perform in small subjects such as rodents. The aims of this study were to 1) evaluate ST to air puff under binocular microlaryngoscopy in rats to evaluate laryngeal sensory disorders, 2) determine sensory thresholds at varying target locations, and 3) determine the ideal depth of anesthesia. STUDY DESIGN: Animal study. METHODS: Rats were induced with ketamine/xylazine. The level of anesthesia was monitored by spontaneous glottic closure and corneal reflex testing. Air puffs were delivered to the epiglottis, arytenoid, and piriform sinus at varied pressures with pulse time kept constant. Sensation thresholds were determined by direct visualization of the larynx using a binocular microscope. Topical lidocaine was then applied to the larynx and ST was determined. Trials were repeated in a small subset of animals. RESULTS: Twenty-six trials were performed in 14 rats. Mean STs were 39 ± 9.7 mm Hg at the epiglottis, 48.8 ± 10.5 at the arytenoid, and not detectable at the pyriform sinus. Repeated trials demonstrated consistent results. Lidocaine effectively ablated the LAR in each trial. The LAR was difficult to induce while corneal reflex was absent and was difficult to distinguish from spontaneous glottic closures while under lighter sedation. CONCLUSION: Air pulse stimulation in rats is a simple, reliable, and effective way to determine laryngopharyngeal STs in rats and can be used as an efficient and affordable method for experimentation involving laryngeal sensory disorders. LEVEL OF EVIDENCE: NA. Laryngoscope, 127:E265-E269, 2017.

Acoustic analysis of snoring sounds originating from different sources determined by drug-induced sleep endoscopy.

OBJECTIVE: To discuss the possibility of fundamental frequency (F0) and formant frequency (FF) to generally differentiate the sources of snoring sounds determined by drug-induced sleep endoscopy (DISE). METHODS: A total of 74 snoring subjects underwent DISE and snoring sounds were recorded simultaneously. The noise-suppressed snoring sounds were analyzed and classified into different groups based on the sources of vibration identified by DISE. F0 and FFs were calculated. RESULTS: Totally, 516 snoring sounds from three vibrating sources (the palate, combined the palate and the lateral wall, the lateral wall) of 47 patients were divided into three groups then analyzed. The levels of F0 and FFs for each group follow the order: Group 1 < Group 2 < Group 3. There was statistical difference between Group 1 and other groups in F0 and F2 (p < .05). The area under the receiver-operator curves (AUC) was F0, at 0.727, and the cut-off value was 134.2 Hz; and F2, at 0.654, and the cut-off value was 2028.0 Hz. CONCLUSIONS: F0 and the second formant frequency (F2) are found to be significantly lower in palatal snoring sound. F0 might be a significant in distinguishing palatal snoring sound from non-palatal snoring sound. F2 is more significant than F1 and F3 in identifying the sources of the snoring sounds but is less sensitive than F0.

Effect of Sleeping Position on Upper Airway Patency in Obstructive Sleep Apnea Is Determined by the Pharyngeal Structure Causing Collapse.

Objectives: In some patients, obstructive sleep apnea (OSA) can be resolved with improvement in pharyngeal patency by sleeping lateral rather than supine, possibly as gravitational effects on the tongue are relieved. Here we tested the hypothesis that the improvement in pharyngeal patency depends on the anatomical structure causing collapse, with patients with tongue-related obstruction and epiglottic collapse exhibiting preferential improvements. Methods: Twenty-four OSA patients underwent upper airway endoscopy during natural sleep to determine the pharyngeal structure associated with obstruction, with simultaneous recordings of airflow and pharyngeal pressure. Patients were grouped into three categories based on supine endoscopy: Tongue-related obstruction (posteriorly located tongue, N = 10), non-tongue related obstruction (collapse due to the palate or lateral walls, N = 8), and epiglottic collapse (N = 6). Improvement in pharyngeal obstruction was quantified using the change in peak inspiratory airflow and minute ventilation lateral versus supine. Results: Contrary to our hypothesis, patients with tongue-related obstruction showed no improvement in airflow, and the tongue remained posteriorly located while lateral. Patients without tongue involvement showed modest improvement in airflow (peak flow increased 0.07 L/s and ventilation increased 1.5 L/min). Epiglottic collapse was virtually abolished with lateral positioning and ventilation increased by 45% compared to supine position. Conclusions: Improvement in pharyngeal patency with sleeping position is structure specific, with profound improvements seen in patients with epiglottic collapse, modest effects in those without tongue involvement and-unexpectedly-no effect in those with tongue-related obstruction. Our data refute the notion that the tongue falls back into the airway during sleep via gravitational influences.