Tracheal Cross-sectional Area Research Articles

Effect of varying cuff sizes with identical inner diameter on endotracheal intubation in critically ill adults: A sealed tracheal controlled trial.

The present study aims to determine the impact of different cuff diameters on the cuff pressure of endotracheal tubes (ETTs) when the trachea is adequately sealed. In the present single-center clinical trial, adult patients who underwent cardiothoracic surgery were assigned to use ETTs from 2 brands (GME and GZW). The primary endpoint comprised of the following: cuff diameter, inner diameter of the ETT, manufacturer, and the number of subjects with tracheal leakage when the cuff pressure was 30 cm H2O. A total of 298 patients were assigned into 2 groups, based on the 2 distinct brands of ETTs: experimental group (n = 122, GME brand) and control group (n = 176, GZW brand). There were no significant differences in baseline characteristics. However, the cuff diameter was significantly smaller in the control group, when compared to the experimental group (P = .001), and the incidence of tracheal leakage was significantly higher in the control group (P = .001). Furthermore, the GME brand ETT had a significantly larger cuff diameter, when compared to the GZW brand ETT. The cuff size would mismatch the tracheal area in clinical practice. Therefore, chest computed tomography is recommended to routinely evaluate the tracheal cross-sectional area during anesthesia, in order to ensure the appropriate cuff size selection.

Micro-CT Imaging of Tracheal Development in Down Syndrome and Non-Down Syndrome Fetuses.

Down syndrome (DS) is associated with airway abnormalities including a narrowed trachea. It is uncertain whether this narrowed trachea in DS is a consequence of deviant fetal development or an acquired disorder following endotracheal intubation after birth. This study aimed to compare the tracheal morphology in DS and non-DS fetuses using microfocus computed tomography (micro-CT). Twenty fetal samples were obtained from the Dutch Fetal Biobank and divided into groups based on gestational age. Micro-CT images were processed to analyze tracheal length, volume, and cross-sectional area (CSA). Mean tracheal length and tracheal volume were similar in DS and non-DS fetuses for all gestational age groups. Mean, minimum, and maximal tracheal CSA were statistically significantly increased in the single DS fetus in the group of 21-24 weeks of gestation, but not in other gestational age groups. In 90% of all studied fetuses, the minimum tracheal CSA was located in the middle third of the trachea. Tracheal development in DS fetuses was similar to non-DS fetuses between 13 and 21 weeks of gestation. This suggests that the narrowed tracheal diameter in DS children may occur later in fetal development or results from postnatal intubation trauma. The narrowest part of the trachea is in majority of DS and non-DS fetuses the middle third. 3 Laryngoscope, 134:4389-4395, 2024.

Inhalation of Carboxymethyl Chitosan Alleviates Posttraumatic Tracheal Fibrosis.

The present study was performed to determine whether the inhalation of carboxymethyl (CM)-chitosan can alleviate tracheal fibrosis in a rabbit model. We designed a rabbit model of tracheal stenosis involving electrocoagulation with a spherical electrode. Twenty New Zealand white rabbits were randomly divided into experimental and control groups (10 animals each). Tracheal damage was successfully established by electrocoagulation in all animals. The experimental group was given CM-chitosan (inhalation for 28 days), while the control group inhaled saline. The effects of CM-chitosan inhalation on tracheal fibrosis were analyzed. Laryngoscopy was performed to evaluate and grade tracheal granulation, while tracheal fibrosis was evaluated by histological examination. The effects of CM-chitosan inhalation on the tracheal mucosa were examined by scanning electron microscopy (SEM), and hydroxyproline content in tracheal scar tissue was determined by enzyme-linked immunosorbent assay (ELISA). Laryngoscopy showed that the tracheal cross-sectional area was smaller in the experimental than control group. The amounts of loose connective tissue and damaged cartilage, as well as the severity of collagen and fibrosis, decreased following inhalation of CM-chitosan. According to the ELISA, the experimental group had low levels of hydroxyproline in the tracheal scar tissue. The findings presented here showed that inhalation of CM-chitosan mitigated posttraumatic tracheal fibrosis in a rabbit model, thus suggesting a potential new treatment for tracheal stenosis.

A novel ex vivo tracheobronchomalacia model for airway stent testing and in vivo model refinement

ObjectivesWe sought to develop an ex vivo trachea model capable of producing mild, moderate, and severe tracheobronchomalacia for optimizing airway stent design. We also aimed to determine the amount of cartilage resection required for achieving different tracheobronchomalacia grades that can be used in animal models. MethodsWe developed an ex vivo trachea test system that enabled video-based measurement of internal cross-sectional area as intratracheal pressure was cyclically varied for peak negative pressures of 20 to 80 cm H2O. Fresh ovine tracheas were induced with tracheobronchomalacia by single mid-anterior incision (n = 4), mid-anterior circumferential cartilage resection of 25% (n = 4), and 50% per cartilage ring (n = 4) along an approximately 3-cm length. Intact tracheas (n = 4) were used as control. All experimental tracheas were mounted and experimentally evaluated. In addition, helical stents of 2 different pitches (6 mm and 12 mm) and wire diameters (0.52 mm and 0.6 mm) were tested in tracheas with 25% (n = 3) and 50% (n = 3) circumferentially resected cartilage rings. The percentage collapse in tracheal cross-sectional area was calculated from the recorded video contours for each experiment. ResultsEx vivo tracheas compromised by single incision and 25% and 50% circumferential cartilage resection produce tracheal collapse corresponding to clinical grades of mild, moderate, and severe tracheobronchomalacia, respectively. A single anterior cartilage incision produces saber-sheath type tracheobronchomalacia, whereas 25% and 50% circumferential cartilage resection produce circumferential tracheobronchomalacia. Stent testing enabled the selection of stent design parameters such that airway collapse associated with moderate and severe tracheobronchomalacia could be reduced to conform to, but not exceed, that of intact tracheas (12-mm pitch, 0.6-mm wire diameter). ConclusionsThe ex vivo trachea model is a robust platform that enables systematic study and treatment of different grades and morphologies of airway collapse and tracheobronchomalacia. It is a novel tool for optimization of stent design before advancing to in vivo animal models.

A preliminary biomechanical study on trachea reconstruction surgery using the clavicular periosteum.

Introduction: The clavicular periosteum is a suitable material for trachea reconstruction. However, because the periosteum is softer and has different mechanical properties than tracheal cartilage, the mechanical loads under physiological conditions after trachea reconstruction may cause collapse or stenosis of the repaired trachea. Methods: In this study, the mechanical properties of the clavicular periosteum were tested, and the 3D trachea geometry was constructed based on CT-scanning images acquired before the surgery. Differing degrees of stenosis (0%, 33%, and 55%) for the repaired trachea sections were predetermined, presenting the different degrees of the tracheal cross-sectional area immediately after clavicular periosteum reconstruction. Then the biomechanical environments of the trachea and the airflow were simulated and analyzed. Results: In the fluid mechanics simulation, the air pressure on the patch area decreased with increasing degrees of stenosis, while the fluid velocity increased as stenosis increased. In solid mechanics simulations, patch area deformation increased as the cross-sectional area of the trachea decreased, and the stress in the patch increased as stenosis increased. Discussion: The solid stress changes may cause tissue remodeling, thickening, and scarring of the patch area. The fluid mechanical changes in the repaired trachea would further aggravate the stenosis. The numerical simulation study would provide references for biomechanical evaluation of trachea reconstruction surgery. The surgical indications may be expanded in the future based on the model prediction results.

Analysis of prognostic risk factors and development of a predictive model for fetuses with right aortic arch with mirror-image branching: a prognostic evaluation method based on ultrasound parameter features.

Prenatal ultrasound plays a crucial role in the diagnosis and classification of right aortic arch (AO) with mirror-image branching (RAA-MB). The recent research in this area has primarily focused on qualitative diagnosis, neglecting the quantitative analysis of ultrasound factors that impact RAA-MB outcomes. This study used echocardiography to measure prenatal ultrasound parameters for vascular ring and trachea in fetuses with RAA-MB, employing a nomogram model to evaluate factors influencing their prognosis, thereby providing a comprehensive characterization of potential outcomes. A retrospective case-control study was conducted from March 2019 to March 2023. A systematic gathering of prenatal echocardiograms and clinical data was completed for a cohort comprising 92 cases of fetal RAA-MB at the Ultrasound Medicine Center of Gansu Provincial Maternity and Child Care Hospital. Participant recruitment was executed through random selection from among those receiving outpatient medical care. Within the cohort, 42 cases were categorized as fetuses with isolated RAA-MB, while the remaining 50 cases were characterized as fetuses with RAA-MB and associated anomalies. Measurements were taken of the angle between the right AO and the ductus arteriosus (DA) (AO-DA), the distance between the AO and DA, the diameter of AO and DA, and the distance growth rate (DGR) of the AO-DA distance. Additionally, measurements were taken of the tracheal anterior-posterior diameter, tracheal left-right diameter, and tracheal circumference in the three-vessel tracheal view. In the AO view, measurements were taken of the tracheal cross-sectional area (TA) and the vessel ring cross-sectional area (VRA). The relationship between these parameters and the prognosis of fetuses with RAA-MB was assessed using logistic regression analysis. A receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic performance of the predictive model based on these factors. The multivariate logistic regression analysis revealed that the independent predictive factors for the prognosis of fetuses with RAA-MB were the AO-DA distance [odds ratio (OR) =0.012], TA (OR =0.401), and VRA (OR =1.103) (all P values <0.001). The area under the ROC curve was 0.891 [95% confidence interval (CI): 0.789-0.914; P<0.001], indicating a high accuracy of the model's predictions. The AO-DA distance, TA, and VRA are factors that influence the prognosis of fetuses with RAA-MB. The column chart model constructed based on these parameters can effectively provide a reference for predicting the risk of adverse outcomes in fetuses with RAA-MB.

Predicting tracheal work of breathing in neonates based on radiological and pulmonary measurements.

Tracheomalacia is an airway condition in which the trachea excessively collapses during breathing. Neonates diagnosed with tracheomalacia require more energy to breathe, and the effect of tracheomalacia can be quantified by assessing flow-resistive work of breathing (WOB) in the trachea using computational fluid dynamics (CFD) modeling of the airway. However, CFD simulations are computationally expensive; the ability to instead predict WOB based on more straightforward measures would provide a clinically useful estimate of tracheal disease severity. The objective of this study is to quantify the WOB in the trachea using CFD and identify simple airway and/or clinical parameters that directly relate to WOB. This study included 30 neonatal intensive care unit subjects (15 with tracheomalacia and 15 without tracheomalacia). All subjects were imaged using ultrashort echo time (UTE) MRI. CFD simulations were performed using patient-specific data obtained from MRI (airway anatomy, dynamic motion, and airflow rates) to calculate the WOB in the trachea. Several airway and clinical measurements were obtained and compared with the tracheal resistive WOB. The maximum percent change in the tracheal cross-sectional area (ρ = 0.560, P = 0.001), average glottis cross-sectional area (ρ = -0.488, P = 0.006), minute ventilation (ρ = 0.613, P < 0.001), and lung tidal volume (ρ = 0.599, P < 0.001) had significant correlations with WOB. A multivariable regression model with three independent variables (minute ventilation, average glottis cross-sectional area, and minimum of the eccentricity index of the trachea) can be used to estimate WOB more accurately (R2 = 0.726). This statistical model may allow clinicians to estimate tracheal resistive WOB based on airway images and clinical data.NEW & NOTEWORTHY The work of breathing due to resistance in the trachea is an important metric for quantifying the effect of tracheal abnormalities such as tracheomalacia, but currently requires complex dynamic imaging and computational fluid dynamics simulation to calculate it. This study produces a method to predict the tracheal work of breathing based on readily available imaging and clinical metrics.

Predictive risk score of respiratory complications in children with mediastinal tumors: A case-control study.

The aim of this study was to examine risk factors of respiratory complications at the diagnosis and establish an algorithm of clinical management in children and adolescents with mediastinal tumors. We retrospectively collected clinical information of all children and adolescents who presented with mediastinal tumors at Saitama Children's Medical Center from 1999 to 2019, including age, sex, pathological diagnosis, eight major clinical symptoms (cough, dyspnea, hypoxia, orthopnea, chest pain, wheeze, superior vena cava syndrome, and stridor), chest computed tomography (CT) findings (tumor location, mediastinal mass ratio, pleural fluid, pericardial effusion, and compression of trachea and bronchi), types of diagnostic procedure and anesthesia, respiratory complications (severe hypoxia, difficult ventilation, respiratory failure, and cardiopulmonary arrest), and clinical outcome. Subsequently, we calculated the risk score for predicting respiratory complications by combining clinical and radiological findings. Of the 57 patients, 7 (12%) developed respiratory complications. Cough, dyspnea, hypoxia, and orthopnea were significantly more common in patients with complications (p=0.02, p=0.02, p < 0.01, p=0.03, respectively). The reduction of percentage of tracheal cross-sectional area (%TCA) and compression of the carina in chest CT were also significantly more common in patients with complications (p < 0.01 and <0.01, respectively). We calculated the risk score of respiratory complications by combining cough, wheeze, stridor, orthopnea, dyspnea, hypoxia, %TCA < 0.5, and compression of the carina. A risk score≥ 7 showed high predictive accuracy for complications (sensitivity: 100%, specificity: 97.7%, positive likelihood ratio: 43.0). The risk score combining clinical symptoms with radiological findings is a promising predictive tool for respiratory complications in children with mediastinal tumors.

Dynamic Volumetric Computed Tomography Angiography is an Effective Method to Evaluate Tracheomalacia in Children.

Standard methods to evaluate tracheal pathology in children, including bronchoscopy, may require general anesthesia. Conventional dynamic proximal airway imaging in noncooperative children requires endotracheal intubation and/or medically induced apnea, which may affect airway mechanics and diagnostic performance. We describe a technique for unsedated dynamic volumetric computed tomography angiography (DV-CTA) of the proximal airway and surrounding vasculature in children and evaluate its performance compared to the reference-standard of rigid bronchoscopy. Children who had undergone DV-CTA and bronchoscopy in one-year were retrospectively identified. Imaging studies were reviewed by an expert reader blinded to the bronchoscopy findings of primary or secondary tracheomalacia. Airway narrowing, if present, was characterized as static and/or dynamic, with tracheomalacia defined as >50% collapse of the tracheal cross-sectional area in exhalation. Pearson correlation was used for comparison. Over a 19-month period, we identified 32 children (median age 8 months, range 3-14 months) who had undergone DV-CTA and bronchoscopy within a 90-day period of each other. All studies were unsedated and free-breathing. The primary reasons for evaluation included noisy breathing, stridor, and screening for tracheomalacia. There was excellent agreement between DV-CTA and bronchoscopy for diagnosis of tracheomalacia (κ=0.81, p < 0.001), which improved if children (n=25) had the studies within 30 days of each other (κ=0.91, p < 0.001). CTA provided incremental information on severity, and cause of secondary tracheomalacia. For most children, DV-CTA requires no sedation or respiratory manipulation and correlates strongly with bronchoscopy for the diagnosis of tracheomalacia. 3 Laryngoscope, 133:410-416, 2023.

Tracheal narrowing in children and adults with mucopolysaccharidosis type IVA: evaluation with computed tomography angiography.

Mucopolysaccharidosis type IVA (MPS IVA) is characterized by progressive skeletal dysplasia and respiratory issues with difficult airway management during anesthesia. To characterize tracheal abnormalities in children and adults with MPS IVA including interplay of the trachea, vasculature, bones and thyroid at the thoracic inlet. Computed tomography (CT) angiograms of the chest were analyzed for trachea shape, narrowing and deviation at the thoracic inlet, course of vasculature, bone alignment and thyroid location. The tracheal cross-sectional area was measured at the cervical, thoracic inlet and intrathoracic levels. Thirty-seven patients (mean age: 18.1years) were included. The mean tracheal cross-sectional area narrowing at the thoracic inlet was 63.9% (range: -2.1-96%), with a trend for increased tracheal narrowing in older children. The trachea was commonly deviated rightward posterior (22/37, 59%). T- or W-shaped tracheas had two times greater tracheal narrowing than D- or U-shaped tracheas (P<0.05). The brachiocephalic artery was tortuous in 35/37 (95%) with direct impingement on the trachea in 24/37 (65%). No correlation was observed between bony thoracic inlet diameter and tracheal narrowing. The thyroid was located in the thoracic inlet in 28/37 (76%) cases, significantly associated with tracheal narrowing (P=0.016). Narrowing, deviation and abnormal shape of the trachea at the thoracic inlet are common in children and adults with MPS IVA, with a trend toward increased narrowing with advancing age in children. A W- or T-shaped trachea is associated with focal tracheal narrowing. Crowding of the thoracic inlet, due to vascular tortuosity and thyroid position, appears to play a major role.

Correlation between Computed Tomographic Analysis and Pulmonary Function Measurements in Patients with Relapsing Polychondritis

Background: Relapsing polychondritis (RP) is a rare systemic disease of unknown origin, with cartilaginous involvement in multiple organs. Airway involvement is the most important prognostic factor in RP. Objectives: Spirometric measurements and minimum tracheal cross-sectional area (mtCSA) have been reported as useful to assess the degree of airway stenosis. Because the length and severity of tracheal involvement in RP can vary, mtCSA might not provide enough information to assess tracheal abnormalities. We introduced tracheal volume (TrV) as a new method to evaluate correlations between chest computed tomography (CT) measurements and pulmonary function tests, including impulse oscillometry (IOS). Method: We analyzed chest CT images, spirometry, and IOS collected at our institution from April 2004 to March 2019. We calculated correlations between chest CT measurements using software (TrV, TrV/tracheal length [TrV/TL], and mtCSA) and pulmonary function parameters. Results: Twenty-five of 73 clinically diagnosed patients with RP were included. Spirometric findings showed moderate airway obstruction. Peak flow (PEF) was strongly correlated with mtCSA, TrV, and TrV/TL (ρ = 0.74, p < 0.001). FEV1 was significantly correlated with mtCSA (ρ = 0.56, p = 0.004), TrV (ρ = 0.52, p = 0.007), and TrV/TL (ρ = 0.53, p = 0.006). Whereas respiratory resistance at 5 Hz (R5) and 20 Hz (R20) and resonant frequencies (RFs) were significantly correlated with TrV (ρ = −0.46, p = 0.021; ρ = −0.46, p = 0.046; and ρ = −0.42, p = 0.037, respectively), IOS parameters and mtCSA were not. Conclusions: In patients with RP, TrV and mtCSA were strongly correlated with spirometric measurements. Respiratory resistances assessed by IOS correlated only with TrV. This suggests TrV assessment reflects pulmonary function in patients with RP more appropriately than mtCSA.

Tracheal branching in ants is area-decreasing, violating a central assumption of network transport models.

The structure of tubular transport networks is thought to underlie much of biological regularity, from individuals to ecosystems. A core assumption of transport network models is either area-preserving or area-increasing branching, such that the summed cross-sectional area of all child branches is equal to or greater than the cross-sectional area of their respective parent branch. For insects, the most diverse group of animals, the assumption of area-preserving branching of tracheae is, however, based on measurements of a single individual and an assumption of gas exchange by diffusion. Here we show that ants exhibit neither area-preserving nor area-increasing branching in their abdominal tracheal systems. We find for 20 species of ants that the sum of child tracheal cross-sectional areas is typically less than that of the parent branch (area-decreasing). The radius, rather than the area, of the parent branch is conserved across the sum of child branches. Interpretation of the tracheal system as one optimized for the release of carbon dioxide, while readily catering to oxygen demand, explains the branching pattern. Our results, together with widespread demonstration that gas exchange in insects includes, and is often dominated by, convection, indicate that for generality, network transport models must include consideration of systems with different architectures.

Dynamics of the Tracheal Airway and Its Influences on Respiratory Airflows: An Exemplar Study.

Respiration is a dynamic process accompanied by morphological changes in the airways. Although deformation of large airways is expected to exacerbate pulmonary disease symptoms by obstructing airflow during increased minute ventilation, its quantitative effects on airflow characteristics remain unclear. Here, we used in vivo dynamic imaging and examined the effects of tracheal deformation on airflow characteristics under different conditions based on imaging data from a single healthy volunteer. First, we measured tracheal deformation profiles of a healthy lung using magnetic resonance imaging (MRI) during forced exhalation, which we simulated to characterize the subject-specific airflow patterns. Subsequently, for both inhalation and exhalation, we compared the airflows when the modeled deformation in tracheal cross-sectional area was 0% (rigid), 33% (mild), 50% (moderate), or 75% (severe). We quantified differences in airflow patterns between deformable and rigid airways by computing the correlation coefficients (R) and the root-mean-square of differences (Drms) between their velocity contours. For both inhalation and exhalation, airflow patterns were similar in all branches between the rigid and mild conditions (R > 0.9; Drms < 32%). However, airflow characteristics in the moderate and severe conditions differed markedly from those in the rigid and mild conditions in all lung branches, particularly for inhalation (moderate: R > 0.1, Drms < 76%; severe: R > 0.2, Drms < 96%). Our exemplar study supports the use of a rigid airway assumption to compute flows for mild deformation. For moderate or severe deformation, however, dynamic contraction should be considered, especially during inhalation, to accurately predict airflow and elucidate the underlying pulmonary pathology.

Improving Quality of Dynamic Airway Computed Tomography Using an Expiratory Airflow Indicator Device.

Dynamic computed tomography (CT) of the airways is increasingly used to evaluate patients with suspected expiratory central airway collapse, but current protocols are susceptible to inadequate exhalation caused by variable patient compliance with breathing instructions during the expiratory phase. We developed and tested a low-cost single-use expiratory airflow indicator device that was designed to improve study quality by providing a visual indicator to both patient and operator when adequate expiratory flow was attained. A total of 56 patients undergoing dynamic airway CT were evaluated, 35 of whom were scanned before introduction of the indicator device (control group), with the rest comprising the intervention group. Lung volumes and tracheal cross-sectional areas on inspiratory/expiratory phases were computed using automated lung segmentation and quantitative software analysis. Inadequate exhalation was defined as absolute volume change of <500 mL during the expiratory phase. Fewer patients in the intervention group demonstrated inadequate exhalation. The average change in volume was higher in the intervention group (P=0.004), whereas the average minimum tracheal cross-sectional area was lower (P=0.01). The described expiratory airflow indicator device can be used to ensure adequate exhalation during the expiratory phase of dynamic airway CT. A higher frequency of adequate exhalation may improve reliability and sensitivity of dynamic airway CT for diagnosis of expiratory central airway collapse.

GW28-e0509 Reference value measurements of tracheal cross-sectional area in fetuses between 22 and 32 weeks

GW28-e0509 Reference value measurements of tracheal cross-sectional area in fetuses between 22 and 32 weeks

Tracheal Stenosis Caused by Thoracic Malignancy: Correlation between CT-Based Tracheal Measurement and Spirometric Values before and after Tracheal Stenting

Background: The correlation between computed tomography (CT)-based tracheal size and spirometry values is unknown in patients with tracheal stenosis by thoracic malignancy, which is often treated by tracheal stenting. Objectives: To evaluate the correlation between the tracheal cross-sectional area (CSA) and spirometric values before and after tracheal stenting, and to confirm that greater improvement in tracheal CSA leads to a larger improvement in spirometry values. Methods: A total of 32 patients with malignant tracheal stenosis underwent tracheal stenting. Before (n = 32) and after (n = 27) treatment, patients underwent chest CT, measuring mean and minimum tracheal CSA values, and spirometry. The correlation between tracheal CSA and each spirometric value was evaluated using Spearman rank correlation analysis. Differences in the pre- and posttreatment tracheal CSA and spirometric values were evaluated using the Wilcoxon matched-pairs test. Results: Significant improvement in the minimum tracheal CSA and in spirometric values was observed after stenting (P P P < 0.05). Conclusions: The tracheal size measured on chest CT correlates with patients’ spirometric values, particularly at the prestenting examination, in patients with malignant tracheal stenosis. The increase in the minimum tracheal CSA after stenting on CT is a predictor for improved spirometric values, which is first demonstrated by this study.

Tracheal CT morphology: correlation with distribution and extent of thoracic adipose tissue.

To evaluate the relationship between adipose tissue measurements and anterior bowing of the posterior tracheal wall in a large nonselected group of patients undergoing CT pulmonary angiography (CTPA). Consecutive patients undergoing CTPA over a 4-month period were analyzed retrospectively. Using an adapted scoring system (posterior bowing, flattening, mild/moderate or severe anterior bowing of the posterior tracheal membrane), the axial morphology and cross-sectional area of the trachea at the narrowest point and 1cm above the aortic arch were evaluated. Measurements of adipose tissue were taken (anterior mediastinal fat width, sagittal upper abdominal diameter and subcutaneous fat thickness at the level of the costophrenic angle). Relationships between tracheal morphology and measurements of adipose tissue were analyzed. 296 patients were included (120 males, 176 females, mean age 59years, range 19-90). Severe anterior bowing of the posterior tracheal wall correlated with increasing sagittal upper abdominal diameter (p = 0.002). Mild/moderate and severe anterior bowing of the posterior tracheal wall correlated with increasing mediastinal fat width (p = 0.000 and p = 0.031, respectively). Tracheal cross-sectional area was inversely correlated with increasing subcutaneous fat thickness (p = 0.022). The findings demonstrate a statistically significant relationship between CT tracheal morphology and adipose tissue measurements in a large nonselected population. • There is increasing interest in the effects of obesity on the airways. • A relationship between anterior bowing of the posterior tracheal wall and adipose tissue measurements is demonstrated. • This is of clinical relevance in an increasingly obese population. • Further studies with functional correlation are required.

Quantitative Computed Tomography Measurement of Tracheal Cross-Sectional Areas in Relapsing Polychondritis: Correlations with Spirometric Values

Background: Although tracheal stenosis occurs in relapsing polychondritis (RP), no studies exist that have clarified correlations between quantitative airway measurement and spirometry in RP patients. Objectives: The aim of this study was to investigate correlations between the cross-sectional area (CSA) of the trachea and spirometric values in patients with RP. Methods: The institutional review board approved this retrospective study, and written informed consent was waived. Twenty-six patients with RP underwent spirometry and chest computed tomography (CT) at full inspiration and end-expiration. On inspiratory and expiratory chest CT images, CSA at the intrathoracic trachea was measured for all CT slices, and the mean and minimum tracheal CSA were obtained. Correlations between the tracheal CSA and spirometric values were assessed by Spearman's rank correlation analysis. Results: Tracheal CSA measurements for inspiratory and expiratory scans were significantly correlated with FEV₁, FEV_25-75%, and peak flow values (ρ = 0.51-0.86, p < 0.01). During each inspiratory or expiratory phase, the minimum tracheal CSA achieved a higher correlation coefficient with spirometric values than the mean CSA. Conclusion: Tracheal dimensions for both inspiratory and expiratory CT are significant predictors of pulmonary function in patients with RP. The narrowest tracheal dimension likely determines the severity of airflow limitation in RP.

Tracheal section is an independent predictor of asthma in patients with nasal polyposis

Airway anatomy could be a risk factor for asthma in susceptible patients with airway hyperresponsiveness. This anatomy can be described by only two parameters, the tracheal cross-sectional area and the homothety ratio, which describes the reduction of calibre at each subsequent generation. Thus, we hypothesized that the tracheal area would be linked to the risk of asthma presence.Tracheal area (measured by acoustic reflexion method) and airway responsiveness to metacholine (expressed as Dose Response Slope) were evaluated in 71 consecutive adult patients with nasal polyposis and normal baseline lung function.Hyperresponsiveness was evidenced in 30/71 patients (42%), and 20/71 patients (28%) were asthmatics. Forced expiratory flows were related to tracheal areas (mean value: 3.22±1.32cm2). In a logistic multivariate analysis, tracheal area and the degree of responsiveness were independent predictors of asthma.In conclusion, this study suggests that airway anatomy, crudely assessed by tracheal section, is an independent determinant of asthma.

Larengotrakeal rekonstrüksiyonda kosta kıkırdağıyla Dacron® greftin karşılaştırması: Deneysel çalışma

Amac: Larenks rekonstruksiyonunda Dacron® implant kullanimini degerlendirmek ve bu materyalin bas-boyun cerrahilerinde potansiyel endikasyonlarini tartismak. Yontem: Her biri 12 Wistar albino sicandan ibaret uc grup olusturuldu. Grup 1 kontrol grubu olup bu gruptaki sicanlarda krikoit kikirdaktan 5. trakea halkasina kadar 6 mm uzunlugunda kesi yapilarak elde edilen 5¥5¥5 mm'lik otolog kosta kikirdagi transplantasyonu yoluyla anterior larengotrakeal rekonstruksiyon gerceklestirildi. Grup 2'de, Grup 1'de oldugu gibi trakea esit uzunluklarda bolumlere ayrildi ve ayni buyuklukte homolog kikirdak nakliyle anterior larengotrakeal rekonstruksiyon gerceklestirildi. Grup 3'de trakea, Grup 1'e esit bolumlere ayrildi ve ayni buyuklukte bir Dacron® greftiyle rekonstruksiyon yapildi. Implantasyondan sonraki 12. haftada sicanlar sakrifiye edildi ve hasta gruplar trakea kesit alani, parsiyel oksijen basinci, epitelizasyon, neovaskularizasyon, enflamatuar hucre infiltrasyonu ve yeni kondrosit olusumu acisindan karsilastirildi. Bulgular: Grup 1'de postoperatif 2. gunde pnomotoraks ve Grup 3'de ise 8. gunde granulasyon ve krutlanma nedeniyle birer deney hayvani kaybedildi. Trakea enine kesit alani ve parsiyel oksijen basinci acisindan gruplar arasinda herhangi bir istatistiksel farklilik yoktu. Grup 2 ve Grup 3 arasinda epitel gelisimi ve neovaskularizasyon acisindan istatistiksel bir farklilik yoktu ancak Grup 1, diger iki gruptan anlamli derecede daha iyi idi. Greft reddinde lenfosit infiltrasyonu onemli bir parametre olup gruplar arasinda onemli bir farklilik vardi. Grup 1, diger 2 gruptan daha iyi oldugu gibi Grup 3'un, Grup 2'den hatiri sayilir derecede farkli oldugu belirlendi. Yeni kondrosit gelisimi acisindan Grup 1. ile Grup 2 arasinda anlamli bir farklilik vardi. Sonuc: Epitel, neovaskularizasyon ve kondrosit gelisim skorlari daha iyi oldugu icin otojen kosta kikirdagi trakea ve larenks icin ideal greft materyalidir. Dacron®'un kullanildigi grupta stenoz, enfeksiyon ve rejeksiyon olmadigi, tum deney hayvanlarinda epitel gelisimi ve neovaskularizasyon tatminkâr derecede olustugu icin larenks rekonstruksiyonunda Dacron® implantlari guvenle kullanilabilmektedir.