Airway Diameter Research Articles

V-Type ATPase Mediates Airway Surface Liquid Acidification in Pig Small Airway Epithelial Cells.

In a newborn pig cystic fibrosis (CF) model, the ability of gland-containing airways to fight infection was affected by at least two major host-defense defects: impaired mucociliary transport and a lower airway surface liquid (ASL) pH. In the gland-containing airways, the ASL pH is balanced by CFTR (CF transmembrane conductance regulator) and ATP12A, which, respectively, control HCO3- transport and proton secretion. We found that, although porcine small airway tissue expressed lower amounts of ATP12A, the ASL of epithelial cultures from CF distal small airways (diameter < 200 μm) were nevertheless more acidic (compared with non-CF airways). Therefore, we hypothesized that gland-containing airways and small airways control acidification using distinct mechanisms. Our microarray data suggested that small airway epithelia mediate proton secretion via ATP6V0D2, an isoform of the V0 d subunit of the H+-translocating plasma membrane V-type ATPase. Immunofluorescence of small airways verified the expression of the V0 d2 subunit isoform at the apical surface of Muc5B+ secretory cells, but not ciliated cells. Inhibiting the V-type ATPase with bafilomycin A1 elevated the ASL pH of small airway cultures, in the presence or absence of HCO3-, and decreased ASL viscosity. These data suggest that, unlike large airways, which are acidified by ATP12A activity, small airways are acidified by V-type ATPase, thus identifying V-type ATPase as a novel therapeutic target for small airway diseases.

Phenotypical Characterization of Airway Morphology in Post-Infectious vs Post-Lung Transplantation Bronchiolitis Obliterans

Purpose Post-infectious bronchiolitis obliterans (PIBO) forms a chronic obstructive lung disease in children following a severe viral respiratory infection. Subsequent dysanaptic lung growth, with differential development of the alveolar compartment over the airway compartment, was clinically described, but remains elusive. We therefore performed a detailed 3D airway characterization in PIBO compared to bronchiolitis obliterans syndrome (BOS) after lung transplantation and discarded donor lungs. Methods Explant lungs from matched adult patients who underwent lung transplantation for end-stage PIBO (n=5), redo lung transplantation patients with end-stage BOS (n=5), and discarded donor lungs (n=5) were included. Lungs were air-inflated and frozen in fumes of liquid nitrogen. Ex vivo computed tomography (CT) scans (resolution 700 µm) were obtained and used for radiologic scoring and semi-automated 3D airway segmentation. Next, frozen lungs were sampled on matched locations (n=4/lung) and scanned with microCT (resolution 10 µm). Results Radiologic scoring indicated more airway wall thickening (p=0.079), bronchial dilatation (p=0.087), and pleural thickening (p=0.071) in PIBO vs BOS. The number of airways per generation was similar between groups (p=0.53), but airway diameters were increased in PIBO (generation 6-11) and in BOS lungs (generation 7-10) compared to controls, without differences between PIBO and BOS. Significantly more airways ended in BO lesions in BOS vs PIBO (p=0.016, mean 25.60% vs 12.60%), although the size of the BO lesions was increased in PIBO vs BOS (p=0.032, median 27.23mm³ vs 5.01mm³). Subsequent micro CT assessment revealed a significant lower number of terminal bronchioles (TB) in PIBO (p=0.0009, PIBO: mean 3131 TB/lung, BOS: 8360 TB/lung, controls: 10342 TB/lung), although diameters of TB were similar across groups (p=0.37). In addition, alveolar spaces tended to be larger in PIBO (p=0.070). 3D micro CT analysis confirmed that in BOS, BO lesions are only segmental with preserved TBs, while in PIBO, the airway is completely lost following the obstruction. Conclusion PIBO lungs displayed a more than two-fold decrease in TB compared to BOS, with fewer but larger BO lesions and non-reopening of airways distal from BO. Our findings provide potential pathophysiologic evidence of dysanaptic lung growth in PIBO.

Use of micro‐CT to determine tracheobronchial airway geometries in three strains of mice used in inhalation toxicology as disease models

Aerosol dosimetry estimates for mouse strains used as models for human disease are not available, primarily because of the lack of tracheobronchial airway morphometry data. By using micro‐CT scans of in‐situ prepared lung casts, tracheobronchial airway morphometry for four strains of mice were obtained: Balb/c, AJ, C57BL/6, and Apoe−/−. The automated tracheobronchial airway morphometry algorithms for airway length and diameter were successfully verified against previously published manual and automated tracheobronchial airway morphometry data derived from two identical in‐situ Balb/c mouse lung casts. There was also excellent agreement in tracheobronchial airway length and diameter between the automated and manual airway data for the AJ, C57BL/6, and Apoe−/− mice. Differences in branch angle measurements were partially due to the differences in definition between the automated algorithms and manual morphometry techniques. Unlike the manual airway morphometry techniques, the automated algorithms were able to provide a value for inclination to gravity for each airway. Inclusion of an inclination to gravity angle for each airway along with airway length, diameter, and branch angle make the current automated tracheobronchial airway data suitable for use in dosimetry programs that can provide dosimetry estimates for inhaled material. The significant differences in upper tracheobronchial airways between Balb/c mice and between C57BL/6 and Apoe−/− mice highlight the need for mouse strain‐specific aerosol dosimetry estimates.

Topical application of mitomycin C as an adjunct in treating subglottic stenosis

Topical application of mitomycin C is best used as an adjunct in airway surgeries together with combination of other modalities of endoscopic techniques such as excision, balloon dilatation and laser treatment in treating subglottic stenosis. We present a case of a 12-year-old boy who acquired Cotton–Myer grade 3 subglottic stenosis 6 months post endotracheal intubation. The stenotic segment was treated with cautery-assisted excision followed by balloon dilatation and topical application of mitomycin C at the raw area. The patient recovered well with improvement of airway diameter, no more symptoms, no more events of restenosis and without the need for multiple procedures.

Deficiency of Biogenic Amines Modulates the Activity of Hypoglossal Nerve in the Reserpine Model of Parkinson's Disease.

The underlying cause of respiratory impairments appearing in Parkinson’s disease (PD) is still far from being elucidated. To better understand the pathogenesis of respiratory disorders appearing in PD, we studied hypoglossal (HG) and phrenic (PHR) motoneuron dysfunction in a rat model evoked with reserpine administration. After reserpine, a decrease in the baseline amplitude and minute HG activity was noted, and no depressive phase of the hypoxic ventilatory response was observed. The pre-inspiratory time of HG activity along with the ratio of pre-inspiratory time to total respiratory cycle time and the ratio of pre-inspiratory to inspiratory amplitude were significantly reduced during normoxia, hypoxia, and recovery compared to sham rats. We suggest that the massive depletion of not only dopamine, but above all noradrenaline and serotonin in the brainstem observed in our study, has an impact on the pre-inspiratory activity of the HG. The shortening of the pre-inspiratory activity of the HG in the reserpine model may indicate a serious problem with maintaining the correct diameter of the upper airways in the preparation phase for inspiratory effort and explain the development of obstructive sleep apnea in some PD patients. Therapies involving the supplementation of amine depletion other than dopamine should be considered.

Ultrathin Silicone Stent Placement for Adult Patients

Various types and shapes of silicone stents for treating airway stenosis are now available. The use of ultrathin silicone stents is reasonable in cases where the airway diameter is too small to insert a standard-sized stent even after bronchoscopic dilation. However, they have not been used in adult patients and the optimal insertion technique has not been established. We report an adult patient with a post-tuberculous left main bronchial obstruction that was successfully managed by ultrathin silicone stents placed using both a flexible, thin bronchoscope and a rigid bronchoscope.

Effects of Mandibular Distraction Osteogenesis on Three-Dimensional Upper Airway Anatomy in Newborns Affected by Isolated Pierre Robin Sequence.

Effective airway management is critical to Pierre Robin Sequence treatment. The goal of this study is to assess the three-dimensional changes in airway size and shape in 117 newborns with isolated Pierre Robin sequence who underwent mandibular distraction osteogenesis. During the study period (11/29/2016 to 11/26/2019), 117 newborns affected by isolated Pierre Robin sequence met the inclusion criteria for the present study. All 117 included patients underwent linear distraction. Demographic variables were recorded and analyzed. Cone-beam computed tomography were performed before and after mandibular distraction osteogenesis. A systemic quantitative three-dimensional analysis of size and shape of upper airway was performed. The mean age was 71 day (range 12 to 213). The mean weight was 3.9 kg (range 2.3-6.8). A total of 53 patients are female and 64 are male. When the distraction device was removed, the upper and lower jaws were symmetrically aligned. Pre- and post-distraction comparison clearly showed osteogenesis. For the size of the upper airway, airway volume, anteroposterior dimension of the retroglossal airway, lateral dimension of retroglossal airway, minimum retropalatal area, minimum retroglossal area, average cross-sectional area and minimum cross-sectional area increased significantly after mandibular distraction osteogenesis (P < 0.001). However, the airway length did not change significantly (P > 0.05). For the shape of the upper airway, the lateral/anteroposterior ratio in the retroglossal region and the ratio of the retropalatal airway diameter to the retroglossal airway diameter significantly decreased after mandibular distraction osteogenesis (P < 0.001). The airway uniformity significantly increased after mandibular distraction osteogenesis (P < 0.001). Mandibular distraction osteogenesis for isolated Pierre Robin sequence improved size and shape of the upper airway, further confirming mandibular osteogenesis distraction as an effective surgical modality to address the airway obstruction in newborns affected by isolated Pierre Robin sequence. Cone-beam computed tomography scanning and analysis can serve as a safe and effective examination modality for upper airway applications of PRS newborns.

Laryngotracheal Stenosis: Clinical Aspects and Management Challenges

AbstractLaryngotracheal stenosis (LTS) is a severe condition with a high morbidity rate, described as the narrowing of the upper airway diameter. The etiology of acquired LTS is dominated by prolonged tracheal intubation. The diagnosis is based on endoscopic examination and computed tomography scan imaging providing an exact analysis of the lesion, with precise measurements.We report a descriptive retrospective review based on the analysis of the medical records of a cohort of 18 patients, treated between January 2015 and January 2018 for an acquired LTS.The results showed predominance in young males. The majority (73%) was hospitalized in a reanimation unit under tracheal intubation while the others (27%) underwent a tracheostomy. The location of the stenosis was tracheal in 69% of the patients, laryngeal in 23%, and laryngotracheal in 8%, and the degree of obstruction exceeded 70% in 11.2%. The endoscopic treatment was based on dilatation and endoluminal calibration by the Montgomery T-tube in 77.7% of our patients, circumferential resection by CO2 laser in 11.1%, and endoscopic posterior cordectomy in 11.1% of the cases. The surgical treatment relied on the resection of the stenosis followed by T-tube calibration in 61.1% of our patients, the resection with a termino-terminal anastomosis in 11%, and supraglottic partial laryngectomy in one patient. The follow-up showed major improvement in the clinical symptomatology, but the biggest challenge in LTS remains the occurrence of restenosis.LTS is a severe condition and needs to be always considered in patients with inspiratory dyspnea and a medical history of tracheal intubation. It requires exhaustive endoscopic and imaging exploration with multidisciplinary management and long-term follow-up to prevent and detect the early signs of an eventual recurrence.

Use of Airway Ultrasound in Infants With Unexpected Subglottic Stenosis During Anesthesia Induction: A Case Report

Point-of-care ultrasound has been integrated into airway management because it allows for rapid and noninvasive assessments. We present 2 cases of unexpected subglottic stenosis in infants during induction of anesthesia. Intubation failed even with endotracheal tubes that were small for patients' age. Airway ultrasound was used to measure the subglottic airway diameters, which were 2.0 and 3.0 mm in first and second cases, respectively. The severity of subglottic stenosis in the first case was grade III, requiring emergent tracheostomy. In conclusion, airway ultrasound helps to assess possibility of intubation and plan further airway management in children with unexpected difficult airway.

Rapid prototyping airway and vascular models from 3D rotational angiography: Beans to cup 3D printing

IntroductionThe application of three-dimensional printed models (3DPM) to facilitate the understanding of complex anatomy is continuously evolving. The use of newer imaging modalities like three-dimensional rotational angiograms (3DRA) as source data to create 3DPM has been scarcely reported; however, this feasibility has highlighted another imaging modality useful for creating accurate anatomical replicas that facilitate evaluation before complex procedures. MethodsWe performed a retrospective chart review of 61 patients who had 3DPM produced from a 3DRA after cardiac catheterization at Children's Hospital Colorado between January 2018 and December 2019. Quantitative validation was performed to accurately determine these models' ability to replicate airway and vascular structures and their relationships. ResultsRadiation and contrast doses were not altered when a 3DRA was performed during the procedure to create a 3DPM. When the measurements were compared to validate the models' accuracy in comparison with 3DRA images, a mean difference of less than 0.1 mm was found when assessing vascular and airway diameters. Standard 3DRA protocols were followed in all cases with no additional angiograms, fluoroscopy, contrast doses, or procedural changes made to facilitate the production of a 3DPM. Conclusion3DPM can be routinely printed from 3DRA, allowing the evaluation of vascular and airway structures and their relationships without any changes to standard 3DRA or procedural protocols.

A comparative analysis of aerodynamic and anatomic characteristics of upper airway before and after mini-implant–assisted rapid maxillary expansion

The objective of this research was to observe changes in aerodynamics and anatomic characteristics of the upper airway after mini-implants assisted rapid maxillary expansion and to evaluate the correlation between the 2 changes of the upper airway in young adults. Thirty consecutive patients (mean age, 23.82±3.90years; median, 24.5years; 9 males, 21 females) were involved. Cone-beam computed tomography was taken before activation and over 3months. Three-dimensional models of the upper airway were reconstructed on the basis of cone-beam computed tomography. The anatomic characteristics of the upper airway, including volume, area, transverse, and sagittal diameter, were measured. The aerodynamic characteristics of the upper airway were calculated on the basis of 3-dimensional models using computational fluid dynamics. The correlation between the changes in aerodynamics and anatomic characteristics of the upper airway was explored. The enlargements of the volume of the total pharynx, nasopharynx, and oropharynx were found (9.99%, 20.7%, and 8.84%, respectively). The minimum cross-sectional area increased significantly (13.6%). The airway resistance (R) and maximum velocity (Vmax) decreased significantly in both the inspiration and expiration phase (inspiration: R, -26.8%, Vmax, -15.7%; expiration: R, -24.7%, Vmax, -16.5%). The minimum wall shear stress reduced significantly only in the inspiration phase (-26.3%). The correlations between decreased R and increased volume and minimum cross-sectional area were observed. Mini-implants assisted rapid maxillary expansion is an effective device for improving anatomic characteristics represented by the total volume of the upper airway and minimum cross-sectional area, which contributed to the respiratory function depending on the favorable changes of aerodynamic characteristics including resistance, velocity, and minimum wall shear stress.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Awake Laser Laryngeal Stenosis Surgery.

Awake Laser Laryngeal Stenosis Surgery.

Mandibular advancement splint response is associated with the pterygomandibular raphe.

To investigate whether the presence of tendinous PMR could predict treatment outcome and how it affects lateral wall mechanical properties. Mandibular advancement increases the lateral dimensions of the nasopharyngeal airway via a direct connection from the airway to the ramus of the mandible. The anatomical structure in this region is the pterygomandibular raphe (PMR), but a tendinous component is not always present. Whether tendon presence influences treatment outcome is unknown. In total, 105 participants with obstructive sleep apnea completed detailed anatomical magnetic resonance imaging with and without mandibular advancement. The study design was case-control. Variables were compared between participants with and without the tendon present. The amount of maximum mandibular advancement decreased when pterygomandibular tendon was present (4.0 ± 1.2 mm present versus 4.6 ± 1.4 mm absent, p = 0.04). PMR tendon-absent participants had a lower posttreatment apnea hypopnea index (16 ± 12 events/hour tendon present versus 9 ± 9 events/hour absent, p = 0.007) and were more likely to have complete response (63% versus 36%, p = 0.02). However, tendon-absent participants were more likely to not complete the study (χ 2 (3) = 10.578, p = 0.014). Tendon-absent participants had a greater increase in midline anteroposterior airway diameter (1.6 ± 1.7 mm versus 0.6 ± 2.3 mm, p = 0.04). When PMR tendon is absent, treatment response and amount of maximum advancement improve, possibly at the expense of reduced splint tolerability. Tendon presence may help predict a group less likely to respond to mandibular advancement splint therapy.

Efficacy and Safety Profile of Montgomery T-Tube Implantation in Patients with Tracheal Stenosis

Background Tracheal stenosis is able to lead to airway obstruction. Objective To evaluate the efficacy and safety profile of Montgomery T-tube implantation in patients with tracheal stenosis. Methods Fifty-two patients with tracheal stenosis diagnosed between 2016 and 2019 were included in this retrospective cohort study. The patients were divided into observation group (n = 25 cases) and control group (n = 27). The therapeutic effect, arterial blood gas analysis, arterial oxygen partial pressure (PaO2), arterial carbon dioxide partial pressure (PaCO2), shortness of breath score, airway diameter change, dyspnea score, quality of life, and safety were compared between the two groups before and after treatment. Results The therapeutic effect of the observation group gained better results than that of the control group (84.00% vs. 62.96%). One week after operation, the pH value, SaO2, PaCO2, shortness of breath score, airway diameter change, dyspnea score, life quality, and incidence of postoperative complications in the observation group exerted better results as compared to the control group. Conclusion The implantation of Montgomery T-tube has effective function in terms of improving the symptoms of dyspnea and the life quality of patients with safety profile in patients harboring tracheal stenosis.

Small airway loss in the physiologically ageing lung: a cross-sectional study in unused donor lungs

Physiological lung ageing is associated with a gradual decline in dynamic lung volumes and a progressive increase in residual volume due to diminished elastic recoil of the lung, loss of alveolar tissue, and lower chest wall compliance. However, the effects of ageing on the small airways (ie, airways <2·0 mm in diameter) remain largely unknown. By using a combination of ex-vivo conventional CT (resolution 1 mm), whole lung micro-CT (resolution 150 μm), and micro-CT of extracted cores (resolution 10 μm), we aimed to provide a multiresolution assessment of the small airways in lung ageing in a large cohort of never smokers. For this cross-sectional study, we included donor lungs collected from 32 deceased never-smoking donors (age range 16-83 years). Ex-vivo CT and whole lung high-resolution CT (micro-CT) were used to determine total airway numbers, stratified by airway diameter. Micro-CT was used to assess the number, length, and diameter of terminal bronchioles (ie, the last generation of conducting airways); mean linear intercept; and surface density in four lung tissue cores from each lung, extracted using a uniform sampling approach. Regression β coefficients are calculated using linear regression and polynomial models. Ex-vivo CT analysis showed an age-dependent decrease in the number of airways of diameter 2·0 mm to less than 2·5 mm (β coefficient per decade -0·119, 95% CI -0·193 to -0·045; R2=0·29) and especially in airways smaller than 2·0 mm in diameter (-0·158, -0·233 to -0·084; R2=0·47), between 30 and 80 years of age, but not of the larger (≥2·5 mm) diameter airways (-0·00781, -0·04409 to 0·02848; R2=0·0007). In micro-CT analysis of small airways, the total number of terminal bronchioles per lung increased until the age of 30 years, after which an almost linear decline in the number of terminal bronchioles was observed (β coefficient per decade -2035, 95% CI -2818 to -1252; R2=0·55), accompanied by a non-significant increase in alveolar airspace size (6·44, -0·57 to 13·45, R2=0·10). Moreover, this decrease in terminal bronchioles was associated with the age-related decline of pulmonary function predicted by healthy reference values. Loss of terminal bronchioles is an important structural component of age-related decline in pulmonary function of healthy, non-smoking individuals. Research Foundation-Flanders, KU Leuven, Parker B Francis Foundation, UGent, Canadian Institutes for Health.

Performance Characteristics of Positive Expiratory Pressure Devices.

Positive expiratory pressure (PEP) therapy imposes expiratory flow resistance to increase airway diameter and enhance mucus clearance. PEP is achieved several ways. Oscillatory PEP devices (OPEP) generate repeated occlusions that are known to reduce mucus viscosity. There are many marketed devices, but comparative performance is mostly unreported. The purpose of this study was to evaluate performance characteristics of many PEP/OPEP devices. For OPEP devices, we defined an optimal performance metric by creating an oscillation index that combines the OPEP performance characteristics. PEP devices (TheraPEP, EzPAP, VersaPAP, Resistex, AccuPEP, AccuPAP, and Threshold PEP) and OPEP devices (Acapella DH, Acapella DM, Acapella Choice, ShurClear, Aerobika, VibraPEP, vPEP, and PocketPEP with and without the Oxyjet attachment) were tested by adjusting simulated expiratory flow from 5 L/min to 30 L/min in increments of 5 L/min using a standard flow meter. All devices showed varying performance characteristics. As expiratory flow increased, mean PEP increased for most devices. The TheraPEP showed a mean PEP of 13 cm H2O across all settings. For OPEP devices, there was a major difference between pressure and flow waveforms. The Acapella DH, ShurClear, and Aerobika showed the highest flow amplitude, flow frequency, and oscillation index. PEP devices behaved similarly and as expected, with increased pressure with increased flow (flow resistors) or flow independence (threshold resistors). There was much greater variation in the performance of the OPEP devices. A higher oscillation index indicates better mechanical performance characteristics. Many devices have similar characteristics. However, the devices with the highest oscillation index have the highest flow amplitude and frequency, which may indicate better clinical performance.

In Vivo Characterization of the Swine Airway Morphometry and Motion Based on Computed TomographicImaging During Respiration.

Swine are a commonly used model in translational pulmonary research. However, in vivo airway morphometry during respiration has not been studied in extensive detail using modern imaging tools. Chest computed tomographic was performed in swine (n = 3) at multiple stages of respiration. Morphometric parameters of each airway segment at end-expiration and end-inspiration were compared as well as among matched anatomical regions (proximal and distal; ventral, lateral, and dorsal). Analysis included segment diameter, length, ellipticity, and the bifurcation angle between daughter branches. Deformation of the airway during respiration was qualitatively visualized using a point-to-point deformation map. Comparison of airway generation showed airway diameter and length were larger at end-inspiration in the fourth and seventh generations compared to end-expiration. Bifurcation angle was larger at end-inspiration compared to end-expiration. Analysis by anatomical region showed that length and bifurcation angle were larger at inspiration in the distal airway regions only. Regardless of respiratory phase, the lateral regions had larger diameters and lengths compared to the ventral and dorsal regions at similar generations and proximal regions had larger bifurcation angles. The findings that morphological changes were more prevalent in distal airways during respiration was confirmed by analysis of a deformation map. Compared to human airway models, the relative diameter may be smaller and length may be greater in swine in similar airway generations. This morphometric description of the swine airways during respiration may guide conduct of preclinical translational studies, revealing advantages and limitations of swine models for specific evaluations. Such morphometric parameters may directly determine the suitability of the swine model for the study of lung interventions, in terms of recapitulation of human morphometry dynamics.

USEFULNESS OF VARIOUS DYNAMIC AND STATIC PARAMETERS IN SLEEP MRI STUDIES -DO THEIR INCORPORATION IN ROUTINE REPORTING IN PATIENTS WITH OBSTRUCTIVE SLEEPAPNEA PROVE VALUABLE ?

Background: Sleep MRI is a new emerging non invasive modality in the preoperative evaluation of patients with obstructive sleep apnoea. Rather than subjective, the aim of the study is to evaluate the competency of certain dynamic and static parameters (variables and diemensions), that can be used in day to day reporting. Incorporating such parameters, may prove to be helpful in guiding surgical decision making. Materials and Methods: A retrospective analytical study included 27 subjects with OSA aged between 18 and 70 years using 1.5 T MRI . We measured variables such as the cross-sectional area and diameter of the retropalatal and retroglossal airway during the asleep and awakened states.We also measured comprehensive airway dimensions such as antero-posterior diameter of the tongue, midline saggital diameter of tongue, intermandibular rami distance, mentum spine distance and relative size of the tongue using the spine as the posterior border of the bony confines. Results: 21 patients had significant retropalatal airway compromise, and was evidenced by statistically significant variables in awakened and asleep states. The mean minimum anterior–posterior diameter (mm) of retropalatal airway during respiratory cycle was statistically significant measuring 3.1±1.5 mm in awaken state and 1.1±1.5 mm during asleep state (p- value 0.01). The mean minimum cross sectional area during respiratory cycle was statistically significant measuring 98±11 mm2 in awaken state and 63 ±12 mm2 during asleep state (p- value 0.04). 6 patients had significant retroglossal airway compromise, and was evidenced by statistically significant. The thickness of the soft palate and the relative size of the tongue (0.5± 0.01mm) was statistically significant in these patients (p- value 0.01). Conclusion: Our study shows that retropalatal airway is a significant cause of obstruction in patients with OSA, compared with retroglossal airway. We suggest that, when the compromise of the retroplatine aiway is to be evaluated, variables such as cross sectional area and antero-posterior diameter of the retropalatal airway during the respiratory phase in asleep and awakened states proves valuable and dimensions such as soft palate thickness as tool for objective measurement of OSA. When the compromise of the retroglossal aiway is to be evaluated, the relative size of the tongue , proves offers more advantage than the variables of airway compromise such as area and antero-posterior diameter.To further evaluate if some of our parameters correlate with the outcomes of the surgeries of OSA, a multivariate analysis would have been required.

Endoscopic Wedge Excisions with CO2 Laser for Subglottic Stenosis.

Endoscopic Wedge Excisions with CO2 Laser for Subglottic Stenosis.