Tracheal Area Research Articles

Implantation site dependent differences for tracheal regeneration with iPS cells

Maximum diameter of teratoma formation in tracheal area Maximum diameter of teratoma formation in abdominal area Implantation site dependent differences for tracheal regeneration with iPS cells Mitsuyoshi Imaizumi, MD1; Yukio Nomoto, MD1; Takashi Sugino, MD2; Yuka Sato, PhD3; Koichi Omori, MD1 Department of 1Otolaryngology, 2Basic Pathology and 3Microbiology, Fukushima Medical University School of Medicine, Fukushima, Japan

Tracheal Collapsibility Measured Using End-Expiratory Chest CT in Chronic Airway Disease

Background/Aims: Partial tracheal narrowing can occur during expiration in the normal population. It is not certain whether the trachea collapses more readily in chronic airway disease. We evaluated the tracheal narrowing at end-expiration using computed tomography (CT). Methods: We investigated 45 patients and 22 normal subjects who underwent high-resolution CT and pulmonary function tests. In each subject, two CT images at the same level of the aortic arch were compared: one at end-inspiration and the other at end-expiration. The cross-sectional area and sagittal diameter of the trachea were measured using a hand-tracing method, using the in-program measuring tools of Medical Image Viewer, and the percentage changes of each value were calculated. Results: Of the 45 patients with chronic airway disease, 21 had chronic obstructive pulmonary disease, 16 had bronchial asthma, and 8 had bronchiectasis. The mean change in the cross-sectional area was 13.3% in the patients and 9.0% in the normal subjects (p 0.05). The decrease in tracheal cross-sectional area was greatest in bronchiectasis, while the greatest decrease in sagittal diameter was in bronchial asthma. There was no significant difference in tracheal collapsibility among the disease groups. The percent change in the tracheal cross-sectional area was correlated with the % predicted FVC (r = -0.033, p<0.05) and FEV1 (r = 0.277, p<0.05) in both the patients and normal controls. Conclusions: The decrease in tracheal cross-sectional area at end-expiration measured using chest CT was greater in chronic airway disease than in normal subjects, and was associated with ventilatory function. (Korean J Med 76:172-178, 2009)

Cross-sectional Study of Tracheomegaly in Children after Fetal Tracheal Occlusion for Severe Congenital Diaphragmatic Hernia

To measure tracheal dimensions in children with congenital diaphragmatic hernia (CDH) who had undergone fetoscopic endoluminal tracheal occlusion (FETO) or were treated expectantly during gestation. The study was approved by the local ethics committee. Computed tomography was performed in 23 patients (14 boys and nine girls) aged 1 month to 6.5 years, and the anteroposterior diameter, width, area, and perimeter of the trachea were determined. Seven of the 23 patients had undergone FETO and 16 had been treated expectantly. The relative difference of each parameter between the two most proximal concentric sections of the trachea, just below the larynx, and the two sections on which the trachea was the largest was compared between both groups (Mann-Whitney U test). Regression statistics were applied to maximum and mean tracheal areas as a function of age. Each trachea was divided into quartiles, and mean areas normalized to 3 years of age were analyzed for each quartile as a function of its relative position on the trachea (Student t test). Tracheal width, area, and perimeter were significantly different between both groups. A linear relationship was observed between the maximum and mean tracheal areas and age for both the FETO group (maximum tracheal area: R(2) = 0.83, P = .0045; mean tracheal area: R(2) = 0.92, P = .0005) and the non-FETO group (maximum tracheal area: R(2) = 0.66, P = .0001; mean trachea area: R(2) = 0.66, P = .0001). The maximum tracheal area in both groups tended to decrease toward the age of 5 years. Significantly different mean tracheal areas per tracheal quartile (P < .05) were found for all quartiles except for the proximal one-fourth. The relative difference between proximal and largest tracheal width, area, and perimeter was significantly larger in patients who underwent FETO than in those treated expectantly, demonstrating tracheal dilatation in the former. Measurements of tracheal dimensions at different levels indicate a maximum dilatation in the lower half of the trachea, which tends to level off toward the age of 5 years.

Loss of Cystic Fibrosis Transmembrane Conductance Regulator Function Produces Abnormalities in Tracheal Development in Neonatal Pigs and Young Children

Although airway abnormalities are common in patients with cystic fibrosis (CF), it is unknown whether they are all secondary to postnatal infection and inflammation, which characterize the disease. To learn whether loss of the cystic fibrosis transmembrane conductance regulator (CFTR) might affect major airways early in life, before the onset of inflammation and infection. We studied newborn CFTR⁻(/)⁻ pig trachea, using computed tomography (CT) scans, pathology, and morphometry. We retrospectively analyzed trachea CT scans in young children with CF and also previously published data of infants with CF. We discovered three abnormalities in the porcine CF trachea. First, the trachea and mainstem bronchi had a uniformly small caliber and cross-sections of trachea were less circular than in controls. Second, trachealis smooth muscle had an altered bundle orientation and increased transcripts in a smooth muscle gene set. Third, submucosal gland units occurred with similar frequency in the mucosa of CF and control airways, but CF submucosal glands were hypoplastic and had global reductions in tissue-specific transcripts. To learn whether any of these changes occurred in young patients with CF, we examined CT scans from children 2 years of age and younger, and found that CF tracheas were less circular in cross-section, but lacked differences in lumen area. However, analysis of previously published morphometric data showed reduced tracheal lumen area in neonates with CF. Our findings in newborn CF pigs and young patients with CF suggest that airway changes begin during fetal life and may contribute to CF pathogenesis and clinical disease during postnatal life.

Expiratory Volumetric MDCT Evaluation of Air Trapping in Pediatric Patients With and Without Tracheomalacia

The purpose of this study was to use paired inspiratory-expiratory volumetric MDCT to compare the frequency, severity, and pattern of air trapping in pediatric patients with tracheomalacia with the findings in children without tracheomalacia. The study group consisted of 15 consecutively registered pediatric patients (younger than 18 years) who had tracheomalacia, defined as 50% or greater reduction in tracheal cross-sectional luminal area between end inspiration and end expiration, diagnosed with MDCT and confirmed with bronchoscopy. The comparison group consisted of 15 consecutively registered pediatric patients without evidence of tracheomalacia at MDCT and bronchoscopy. Two blinded pediatric radiologists working in consensus interpreted the randomly viewed end-expiratory thin-section CT images of both groups of children for the presence, severity, and pattern of air trapping at three anatomic levels (upper, middle, and lower lung zones). The severity of air trapping was graded visually on a 5-point scale. The total air trapping scores, obtained by summing the values for the three anatomic levels for the study and comparison groups, were compared by Wilcoxon's rank sum test. The pattern of air trapping was categorized as lobular, segmental, lobar, diffuse, or mixed, and the patterns in the two study groups were compared by Pearson's chi-square test. The study cohort with tracheomalacia consisted of 15 patients (10 boys, five girls; mean age, 2.4 +/- 2.8 years; range, 1 month-11.8 years). The comparison group without tracheomalacia consisted of 15 patients (nine boys, six girls; mean age, 2.7 +/- 2.4 years; range, 1 month-8.1 years). Air trapping was identified in all 15 patients with tracheomalacia (median score, 5.0; range, 3-11) and in 10 of 15 children (67%) in the comparison group (median score, 3.0; range, 1-4). The median total air trapping score was significantly higher in the study cohort than in the comparison group (p = 0.002), but there were no significant differences in the air trapping patterns between the study groups (p = 0.53). Pediatric patients with tracheomalacia have a higher frequency and greater severity of air trapping than do children without tracheomalacia.

Case Scenario: Perioperative Airway Management of a Patient with Tracheal Stenosis

TRACHEAL stenosis is a rare but a life-threatening condition and is caused by congenital problems, postintubation injury, trauma, tracheal tumor, and compression of the trachea by tumor. Although accurate prevalence of this condition is unknown, an incidence of 4.9 cases per million per year is estimated for postintubation tracheal stenosis. A stenosis commonly occurs at the cuff of the tube (intrathoracic trachea) or at the level of the tracheostomy stoma (extrathoracic trachea). Anesthesia of a patient with tracheal stenosis is challenging for anesthesiologists. Depending on the severity and location of the stenosis and the type of surgical procedure, there may be a variety of choices for perioperative airway management such as a facemask, laryngeal mask airway, an tracheal intubation tube, cardiopulmonary bypass, and extracorporeal membrane oxygenation. The American Society of Anesthesiologists practice guidelines for management of the difficult airway primarily focus airway problems caused at the extrathoracic airway and may not be helpful, particularly for managing patients with intrathoracic tracheal stenosis. In this case scenario, we present a patient with severe intrathoracic tracheal stenosis, who required surgery for a lumbar fracture in the prone position. Various airway management strategies and the actual management used are discussed.

Comparison of Standard-Dose and Reduced-Dose Expiratory MDCT Techniques for Assessment of Tracheomalacia in Children

The aim of this study was to assess the effects of radiation dose reduction on the assessment of the tracheal lumen on expiratory multidetector computed tomographic (MDCT) images of pediatric patients referred for evaluation for tracheomalacia (TM). The hospital information system was used to retrospectively identify 20 standard-dose and 20 reduced-dose paired inspiratory and expiratory MDCT studies performed for the evaluation of suspected TM in pediatric patients (aged <or= 18 years). The reduced-dose technique used a 50% reduction of the tube current for the expiratory portion of the study compared to the standard-dose technique. Two experienced pediatric radiologists, who were blinded to the tube current of the study, reported their levels of confidence for measuring the tracheal lumen using a four-point scale ranging from zero (no confidence) to three (highest level of confidence). The difference in confidence level between the two groups of studies was analyzed using the Mann-Whitney U test. The percentage of radiation dose reduction using the reduced-dose technique in comparison to the standard-dose technique was estimated using anthropomorphic thorax phantoms. The presence or absence of TM (>or=50% expiratory reduction in tracheal cross-sectional luminal area) on MDCT imaging was compared to bronchoscopic results for the subset of 32 patients who underwent both procedures. A high level of confidence was reported for measuring the tracheal lumen on MDCT imaging for both standard-dose (median, 3.0) and reduced-dose (median, 3.0) expiratory sequences (P = .80). The total radiation dose of the paired inspiratory-expiratory computed tomographic (CT) exam was decreased by 23% with the reduced-dose technique. TM was diagnosed by CT imaging in seven patients who underwent standard-dose and six patients who underwent reduced-dose paired inspiratory and expiratory MDCT studies. CT results for the presence or absence of TM were concordant with the results of bronchoscopy in all 32 patients who underwent both procedures. The radiation dose of paired inspiratory-expiratory CT imaging can be reduced by 23% while maintaining similar diagnostic confidence for assessment of the tracheal lumen compared to a standard-dose technique in pediatric patients. Thus, a reduced-dose technique is recommended for evaluating TM in children.

Trends in Scientific Interest of the American Broncho-Esophagological Association

The specialty of otolaryngology in the United States has changed dramatically over the past century, and this is particularly true in the field of bronchoesophagology, which has evolved from a new specialty at the beginning of the 20th century to one that is now multidisciplinary and further subspecialized. The purpose of this report was to trace the evolution of bronchoesophagology over the past 60 years by examining and quantitating the scientific subject matter of the annual meetings of the American Broncho-Esophagological Association (ABEA). The Transactions of the ABEA annual meetings from the 1940s to the present day were examined in depth for subject matter, and articles were categorized by topic. Each decade was represented by 3 years. Data were sorted into 3 domains: 1) anatomic area, 2) adult versus pediatric, and 3) subject matter, including neoplasms, infectious diseases, foreign bodies, technologies, function, and trauma. The overall changes were quantified to outline the direction and interests of the ABEA. We reviewed 483 scientific articles from the 1940s into the present decade, with a mean of 69.7 papers (SD, 32.4) representing each decade. Bronchology and pulmonology decreased in percentage of papers, from 43% and 17.9% in 1940 to 1.7% and 2.6%, respectively, in the 2000s. Laryngology evolved from 12.5% to 58.1%. Esophagology peaked in the 1950s at 35.7%, dropped to 4% in the 1980s, and then rose to its present-day level of 15.4%. Trends were also discernible in gastric and tracheal areas. Pediatric topics rose to 26.7% in the 1980s, then declined to their present level of 12.8%. Topics related to aerodigestive tract function increased from 3.6% to 34.2%, and presentation of technology declined from 23.2% in the 1940s to nil in the 2000s. Trends in neoplasms, infectious diseases, foreign bodies, and trauma were less significant. Analysis of the data reveals changing trends in the focus of the ABEA. The changing focus of the ABEA has paralleled scientific advances in our field, as well as the rise of other subspecialties such as interventional pulmonology and gastroenterology.

Radioiodine plus recombinant human thyrotropin do not cause acute airway compression and are effective in reducing multinodular goiter

Recombinant human thyrotropin (rhTSH) reduces the activity of radioiodine required to treat multinodular goiter (MNG), but acute airway compression can be a life-threatening complication. In this prospective, randomized, double-blind, placebo-controlled study, we assessed the efficacy and safety (including airway compression) of different doses of rhTSH associated with a fixed activity of 131I for treating MNG. Euthyroid patients with MNG (69.3 +/- 62.0 mL, 20 females, 2 males, 64 +/- 7 years) received 0.1 mg (group I, N = 8) or 0.01 mg (group II, N = 6) rhTSH or placebo (group III, N = 8), 24 h before 1.11 GBq 131I. Radioactive iodine uptake was determined at baseline and 24 h after rhTSH and thyroid volume (TV, baseline and 6 and 12 months after treatment) and tracheal cross-sectional area (TCA, baseline and 2, 7, 180, and 360 days after rhTSH) were determined by magnetic resonance; antithyroid antibodies and thyroid hormones were determined at frequent intervals. After 6 months, TV decreased significantly in groups I (28.5 +/- 17.6%) and II (21.6 +/- 17.8%), but not in group III (2.7 +/- 15.3%). After 12 months, TV decreased significantly in groups I (36.7 +/- 18.1%) and II (37.4 +/- 27.1%), but not in group III (19.0 +/- 24.3%). No significant changes in TCA were observed. T3 and free T4 increased transiently during the first month. After 12 months, 7 patients were hypothyroid (N = 3 in group I and N = 2 in groups II and III). rhTSH plus a 1.11-GBq fixed 131I activity did not cause acute or chronic changes in TCA. After 6 and 12 months, TV reduction was more pronounced among patients treated with rhTSH plus 131I.

Pharyngeal area measured by acoustic reflection technique while breathing room-air

Although there have been many reports on the airway area measured by breathing 80% He-20% O2 (He-O2) using the acoustic reflection technique (ART), there have been no reports on that by breathing room-air (Air) because of the lack of accuracy in evaluating the trachea. When measuring with He-O2, accidental introduction of Air into the airway makes the measurement inaccurate. Moreover, it is a time-consuming method and is hardly applicable to dyspneic patients. Therefore, we tried to assess whether the airway area, especially the upper airway, can be measured while breathing Air. In order to compare the areas determined by the two methods, area-distance functions from the pharynx to the trachea were arbitrarily divided into 9 divisions at interval of 2.8 cm. Each of these divisions was respectively compared. We took averages of the pharyngeal, tracheal areas in 8 normal subjects. We found no significant difference between the oropharyngeal area measured by breathing Air and that measured by breathing He-O2, and found a significant correlation between them. There was a significant correlation between the hypopharyngeal areas when using the two methods. The average tracheal area by breathing Air is 4.96 +/- 0.50 cm2, which is 40% above that when measured using He-O2 (3.55 +/- 0.32 cm2). In contrast, the average pharyngeal area when breathing Air is 4.13 +/- 0.93 cm2, which overestimates that by breathing He-O2, namely 3.54 %/- 0.84 cm2 by only 17%. In conclusion, it is possible and useful to estimate the pharyngeal area by breathing Air.

Peripheral Rim Enhancement in Tuberculous Mediastinal Lymph Nodes

A 50-year-old Arab woman presented with a 3-month history of fever, weight loss, and tiredness. She noticed mild shortness of breath on exertion a month before presentation. She looked fairly healthy, a few cervical lymph nodes were palpable, and the chest examination showed features of a right-sided pleural effusion. A chest radiograph showed a right pleural effusion and mediastinal widening. Computed tomography (CT) confirmed massive mediastinal lymphadenopathy ( Figures 1 and 2 ). The largest lymph node was seen in the right para tracheal area measuring 5 × 3.5 cm. Bilateral pleural effusions were also seen. As seen in the figures, all the lymph nodes showed characteristic central low attenuation with a peripheral rim of enhancement (arrows). A cervical lymph node biopsy showed caseating necrosis and a few acid-fast bacilli, confirming the diagnosis of tuberculosis. HIV serology was negative. CT accurately defines the extent and placement of the lymph nodes. The low attenuation necrotic lymph nodes with rim enhancement after contrast infusion strongly suggest a diagnosis of mycobacterial infection. 1 A similar appearance may be seen in patients with fungal infection, especially Cryptococosis or Histoplasmosis . This appearance is usually not observed in other causes of mediastinal lyphadenopathy such as metastatic carcinoma, lymphoma, sarcoidosis, or leukemia. Low attenuation areas within the nodes represent areas of caseation necrosis and may be a reliable indicator of disease activity. 2,3

Changes in tracheal dimensions during inspiration and expiration in healthy dogs as detected via computed tomography

To determine the degree of fluctuation in tracheal dimensions between forced inspiration and passive expiration in healthy dogs of various sizes. 10 client-owned dogs with no evidence of respiratory disease or tracheal collapse. Anesthetized dogs underwent a computed tomographic examination during forced inspiration and induced but passive expiration to assess tracheal dimensions. Tracheal height, width, and cross-sectional area were measured at inspiration and expiration, and percentage change in dimension was calculated for each variable. Measurements were acquired in 10 dogs that ranged in body weight from 3.5 to 47.8 kg. Tracheal cross-sectional area at inspiration and expiration was associated with body weight at all 3 tracheal regions. The percentage change in tracheal height and cross-sectional area was associated with body weight in the cervical but not the thoracic-inlet or thoracic regions. The tracheal cross-sectional area changed by as much as 24.2% (mean, 5.5%), 20.0% (mean, 6.0%), and 18.6% (mean, 6.0%) in the cervical, thoracic-inlet, and thoracic regions, respectively. The change in tracheal cross-sectional area from inspiration to expiration was as great as 24% in healthy dogs, and the area was associated with body weight. Respiratory fluctuations appeared to result in changes in tracheal dimension during respiration similar to those reported for humans.

Tracheomalacia in Adults with Cystic Fibrosis: Determination of Prevalence and Severity with Dynamic Cine CT

To determine the prevalence and severity of tracheomalacia in adults with cystic fibrosis (CF) by using dynamic cine multidetector computed tomography (CT) and to correlate these findings with pulmonary function test (PFT) results and the severity of parenchymal lung disease. In this institutional review board-approved HIPAA-compliant study, 40 patients with CF (22 men, 18 women; mean age, 28 years +/- 8 [standard deviation]; age range, 18-54 years) prospectively underwent PFTs, standard thin-section CT, and two dynamic cine multidetector CT acquisitions. Ten control subjects underwent dynamic cine multidetector CT. After standard thin-section CT was completed, dynamic cine multidetector CT was performed during a forced expiratory maneuver and during coughing. Dynamic cine multidetector CT images in nine patients were excluded. Maximal inspiratory, dynamic expiratory, and end-expiratory tracheal luminal areas were compared (Student t test) and correlated (Spearman rank) with PFT results and severity of parenchymal lung disease. Mean predicted forced expiratory volume in 1 second (FEV(1)) was 70.6% +/- 20.7, and mean Bhalla CT score was 41.8% +/- 13.6. In patients with CF, dynamic cine mean tracheal cross-sectional area reduction was 51.7% +/- 18.4 (range, 9%-89%) for forced expiratory maneuvers and 68.8% +/- 11.7 (range, 18%-88%) for coughing (P = .001). Tracheomalacia was demonstrated in 24 (69%) patients and no control subjects during forced expiratory maneuvers (P = .001) and in 10 (29%) patients and one (10%) control subject during coughing. For end-expiration images, mean tracheal luminal reduction was 16.1% +/- 14.0% (range, 0.0%-53.0%), with one patient demonstrating tracheal luminal reduction of more than 50%. There was no correlation between tracheal cross-sectional luminal reduction and either predicted FEV(1) or CT Bhalla score. Tracheomalacia depicted at dynamic cine multidetector CT is a highly prevalent finding in adults with CF. http://radiology.rsnajnls.org/cgi/content/full/2522081956/DC1.

Tracheal Collapsibility in Healthy Volunteers during Forced Expiration: Assessment with Multidetector CT

To assess forced expiratory tracheal collapsibility in healthy volunteers by using multidetector computed tomography and to compare the results with the current diagnostic criterion for tracheomalacia. An institutional review board approved this HIPAA-compliant study. After informed consent was obtained, 51 healthy volunteers (age range, 25-75 years) with normal spirometry results and no history of smoking or risk factors for tracheomalacia were prospectively studied. Volunteers were imaged with a 64-detector row scanner, with spirometric monitoring at total lung capacity and during forced exhalation, with 40 mAs, 120 kVp, and 0.625-mm detector collimation. Cross-sectional area and sagittal and coronal diameters of the trachea were measured 1 cm above the aortic arch and 1 cm above the carina. The percentage of expiratory collapse, the reduction in sagittal and coronal diameters, and the number of participants exceeding the current diagnostic criterion (>50% expiratory reduction in cross-sectional area) for tracheomalacia were calculated. The final study population included 25 men and 26 women (mean age, 50 years). The mean percentage of expiratory reduction in tracheal lumen cross-sectional area was 54.34% +/- 18.6 (standard deviation) in the upper trachea and 56.14% +/- 19.3 in the lower trachea. Forty (78%) participants exceeded the current diagnostic criterion for tracheomalacia in the upper and/or lower trachea. Decreases in cross-sectional area of the upper and lower trachea correlated well with decreases in sagittal (r = 0.807 and 0.688, respectively) and coronal (r = 0.779 and 0.751, respectively) diameters (P < .001 for each correlation). Healthy volunteers demonstrate a wide range of forced expiratory tracheal collapse, frequently exceeding the current diagnostic criterion for tracheomalacia.

Prevalence of Tracheal Collapse in an Emphysema Cohort as Measured With End-expiration CT

To retrospectively investigate the prevalence of tracheal collapse in an emphysema cohort. The occurrence of a large degree of tracheal collapse may have important implications for the clinical management of respiratory symptoms and air trapping in patients with emphysema. Paired full-inspiratory and end-expiratory thin-section volumetric computed tomographic scans were available for 1071 long-term smokers with clinically and physiologically confirmed emphysema. The percentage reduction in the cross-sectional tracheal luminal area from full-inspiration to end-expiration was automatically computed at 2.5-mm intervals along the centerline of the trachea using customized software. Maximal tracheal collapse did not follow a normal distribution in the emphysema cohort (P < .0001, skewness/kurtosis tests for normality); the median collapse was 18% (intraquartile range, 11%-30%). Statistically significant differences were found in the distribution of maximal collapse by gender (P < .005, Wilcoxon rank sum test). Overall, 10.5% of men and 17.1% of women showed evidence of tracheomalacia on the basis of the criterion of a reduction of 50% or greater in cross-sectional tracheal luminal area at end-expiration. This study offers insights into the prevalence of tracheal collapse in a cohort of patients with emphysema; future work is needed to determine the possible relationship between tracheal collapse and air trapping in subjects with emphysema.

MDCT Evaluation of the Prevalence of Tracheomalacia in Children With Mediastinal Aortic Vascular Anomalies

The purpose of this study is to determine the prevalence of tracheomalacia (TM) associated with different types of mediastinal aortic vascular anomalies in symptomatic children using paired inspiratory-expiratory multidetector computed tomography (MDCT). The study group consisted of 15 consecutive symptomatic pediatric patients (12 males/3 females; mean age of 4.4 y; age range of 2 wk to 16 y) with mediastinal aortic vascular anomalies, who were referred for paired inspiratory-expiratory MDCT during a 35-month time period. Computed tomography (CT) angiography was also concurrently performed during the end-inspiration phase of the study. Two radiologists in consensus reviewed all CT images in a randomized and blinded fashion. End-inspiration and end-expiration CT images were reviewed for the presence and severity of tracheal narrowing and the type of mediastinal aortic vascular anomaly involved. TM was defined as > or =50% reduction in tracheal cross-sectional luminal area between end-inspiration and end-expiration. The presence of TM was correlated with the type of mediastinal aortic vascular anomaly and compared with the bronchoscopy results when available (n=9). Mediastinal aortic vascular anomalies included innominate artery compression (IAC) (n=6), a right aortic arch with an aberrant left subclavian artery (n=5), double aortic arch (n=3), and a left aortic arch with an aberrant right subclavian artery (n=1). Eight of 15 (53.3%) patients demonstrated TM. TM was seen in all 6 patients (100%) with IAC, 1 of 3 (33.3%) patients with double aortic arch, and 1 of 5 (20%) patients with a right aortic arch with an aberrant left subclavian artery. CT results were concordant with the results of bronchoscopy in all patients who underwent this procedure (n=9). Symptomatic pediatric patients with mediastinal aortic vascular anomalies have a relatively high prevalence of TM, especially those with IAC. Paired inspiratory-expiratory MDCT should be considered part of the routine preoperative evaluation of TM in symptomatic children with IAC and also has the potential to play a role in evaluating patients with other mediastinal aortic vascular anomalies.

Computed Tomography Analysis of Airway Dimensions and Lung Density in Patients with Sarcoidosis

Background: It was previously reported that visual scores of the lung opacities were associated with lung function in patients with sarcoidosis. However, there are no reports on the evaluation of airway dimensions or lung density by computed tomography (CT) in sarcoidosis patients. Objectives: The aim of this study was to investigate whether airway dimensions and lung densities assessed by CT associate with pulmonary function in patients with sarcoidosis. Methods: CT scanning was performed in 43 sarcoidosis patients and lung densities were measured using in-house software. Means and standard deviations of lung density, kurtosis and skewness of lung density histograms were calculated. Tracheal area and airway wall area/total airway area (WA%) of the right apical bronchus were also measured. Pulmonary function tests were performed on the same day. Results: Increased standard deviation of lung density and decreased kurtosis and skewness of lung density histograms were all associated with decreased total lung capacity, vital capacity and diffusion capacity. Increased standard deviation of lung density was also associated with decreased percentages of forced expiratory volume in 1 s and peak expiratory flow (%PEF). There was a positive correlation between tracheal area corrected by body surface area and %PEF, and negative correlation between WA% and %PEF. Stepwise regression analysis showed that increased standard deviation of lung density and decreased tracheal area were independently associated with lower %PEF. Conclusions: Thus, in sarcoidosis, densitometric parameters reflect restrictive lung function impairment. In addition to parenchymal lesions, it is concluded that the luminal area of the central airways also affects PEF.

The anaesthetic management of children with anterior mediastinal masses

Children with anterior mediastinal masses may experience serious complications during general anaesthesia. We retrospectively surveyed the records of children with an anterior mediastinal mass who had been admitted to our hospital over a 7 year period. The presence of pre-operative symptoms or signs, findings of any special investigations performed and the anaesthetic outcome were noted. All radiological investigations were studied and tracheal compression measured. The majority of patients presented with severe clinical signs. There was a poor relationship between clinical signs and size of tumour or tracheal compression on CT scan. Corticosteroids were used prior to diagnosis in 33% of patients, all of whom were considered high risk. A clear diagnosis was made in 95% of these patients. The overall complication rate was 20% and 5% of patients had a serious complication related to anaesthesia. Stridor was the only sign that predicted an anaesthetic complication. Peri-operative respiratory complications were confined to patients with an isolated tracheal cross-sectional area less than 30% normal or less than 70% and associated with bronchial compression.

The Effect of Nigellone and Thymoquinone on Inhibiting Trachea Contraction and Mucociliary Clearance

NIGELLA SATIVA L. has many effects including those on the gastrointestinal tract and trachea and is, therefore, used in the Mediteranean area and in India/Pakistan. Our aim was to investigate the effect of two main constituents, nigellone and thymoquinone, on trachea (antispasmodic effect) and their influence on respiratory clearance. The effects on Ba (2+)-, carbachol- and leukotriene-induced trachea contractions and the transport of the fluorescence dye rhodamin B concerning ciliary action in the tracheal area were investigated using a microdialysis technique. Nigellone and high concentrations of thymoquinone had a concentration-dependent inhibitory effect on the trachea when being contracted by the depolarizing effect of Ba (2+). The trachea contractions induced by leukotriene-d (4) were inhibited by nigellone and by thymoquinone. The cholinergic system (stimulation by carbachol) was hardly involved. The rate of ciliary clearance (mucociliary transport) was slightly modified by a high thymoquinone concentration (153.0 vs. 505.0 sec/12 mm distance, respectively), and was highly increased by nigellone (217.5 vs. 505.0 sec/12 mm distance). In conclusion, this study provides evidence for an antispasmodic effect and an increase in mucociliary clearance for nigellone but not for thymoquinone. Altogether the data indicate that nigellone but not thymoquinone may be useful in treatment of different respiratory diseases.

MDCT assessment of tracheomalacia in symptomatic infants with mediastinal aortic vascular anomalies: preliminary technical experience

Mediastinal aortic vascular anomalies are relatively common causes of extrinsic central airway narrowing in infants with respiratory symptoms. Surgical correction of mediastinal aortic vascular anomalies alone might not adequately treat airway symptoms if extrinsic narrowing is accompanied by intrinsic tracheomalacia (TM), a condition that escapes detection on routine end-inspiratory imaging. Paired inspiratory-expiratory multidetector CT (MDCT) has the potential to facilitate early diagnosis and timely management of TM in symptomatic infants with mediastinal aortic vascular anomalies. To assess the technical feasibility of paired inspiratory-expiratory MDCT for evaluating TM among symptomatic infants with mediastinal aortic vascular anomalies. The study group consisted of five consecutive symptomatic infants (four male, one female; mean age 4.1 months, age range 2 weeks to 6 months) with mediastinal aortic vascular anomalies who were referred for paired inspiratory-expiratory MDCT during a 22-month period. CT angiography was concurrently performed during the end-inspiration phase of the study. Two pediatric radiologists in consensus reviewed all CT images in a randomized and blinded fashion. The end-inspiration and end-expiration CT images were reviewed for the presence and severity of tracheal narrowing. TM was defined as > or =50% reduction in tracheal cross-sectional luminal area between end-inspiration and end-expiration. The presence of TM was compared to the bronchoscopy results when available (n = 4). Paired inspiratory-expiratory MDCT was technically successful in all five patients. Mediastinal aortic vascular anomalies included a right aortic arch with an aberrant left subclavian artery (n = 2), innominate artery compression (n = 2), and a left aortic arch with an aberrant right subclavian artery (n = 1). Three (60%) of the five patients demonstrated focal TM at the level of mediastinal aortic vascular anomalies. The CT results were concordant with the results of bronchoscopy in all patients who underwent bronchoscopy (n = 4). Paired inspiratory-expiratory MDCT is technically feasible for evaluating TM in symptomatic infants with mediastinal aortic vascular anomalies and has the potential to facilitate prompt diagnosis and treatment.