Tracheal Area Research Articles

Low-Dose Whole-Chest Dynamic CT for the Assessment of Large Airway Collapsibility in Patients with Suspected Tracheobronchial Instability.

Purpose To quantify tracheal collapsibility using low-dose four-dimensional (4D) CT and to compare visual and quantitative 4D CT-based assessments with assessments from paired inspiratory-expiratory CT, bronchoscopy, and spirometry. Materials and Methods The authors retrospectively analyzed 4D CT examinations (January 2016-December 2022) during shallow respiration in 52 patients (mean age, 66 years ± 12 [SD]; 27 female, 25 male), including 32 patients with chronic obstructive pulmonary disease (mean forced expiratory volume in 1 second percentage predicted [FEV1%], 50% ± 27), with suspected tracheal collapse. Paired CT data were available for 27 patients and bronchoscopy data for 46 patients. Images were reviewed by two radiologists in consensus, classifying patients into three groups: 50% or greater tracheal collapsibility, less than 50% collapsibility, or fixed stenosis. Changes in minimal tracheal lumen area, tracheal volume, and lung volume from inspiration to expiration were quantified using YACTA software. Tracheal collapsibility between groups was compared employing one-way analysis of variance (ANOVA). For related samples within one group, ANOVA with repeated measures was used. Spearman rank order correlation coefficient was calculated for collapsibility versus pulmonary function tests. Results At 4D CT, 25 of 52 (48%) patients had tracheal collapsibility of 50% or greater, 20 of 52 (38%) less than 50%, and seven of 52 (13%) had fixed stenosis. Visual assessment of 4D CT detected more patients with collapsibility of 50% or greater than paired CT, and concordance was 41% (P < .001). 4D CT helped identify more patients with tracheal collapsibility of 50% or greater than did bronchoscopy, and concordance was 74% (P = .39). Mean collapsibility of tracheal lumen area and volume at 4D CT were higher for 50% or greater visually assessed collapsibility (area: 53% ± 9 and lumen: 52% ± 10) compared with the less than 50% group (27% ± 9 and 26% ± 6, respectively) (P < .001), whereas both tracheal area and volume were stable for the fixed stenosis group (area: 16% ± 12 and lumen: 21% ± 11). Collapsibility of tracheal lumen area and volume did not correlate with FEV1% (rs = -0.002 to 0.01, P = .99-.96). Conclusion The study demonstrated that 4D CT is feasible and potentially more sensitive than paired CT for central airway collapse. Expectedly, FEV1% was not correlated with severity of tracheal collapsibility. Keywords: CT-Quantitative, Tracheobronchial Tree, Chronic Obstructive Pulmonary Disease, Imaging Postprocessing, Thorax Supplemental material is available for this article. © RSNA, 2024.

Can lung anatomy predict the development of COVID-19 pneumonia in RT-PCR positive cases?

Purpose: The objective of this study was to investigate the relationship between Coronavirus disease 2019 (COVID-19) pneumonia and anatomical characteristics, including tracheobronchial and fissure variations, right/left main bronchus angle, carina angle, and large airway diameter, in patients who tested positive for the virus via reverse transcription-polymerase chain reaction (RT-PCR) at the outset of the pandemic. Materials and Methods: This cross-sectional study included 165 cases with positive RT-PCR tests who were admitted between March and June 2020 and subsequently scanned with thin-section unenhanced chest computed tomography (CT). They were divided into two groups according to the presence of pneumonia based on the chest CT images. Results: In our study, a total of 165 cases were analyzed, pneumonia was found in 35 of 76 (46.05%) female patients and 51 of 89 (57.30%) male patients. COVID-19 pneumonia was observed in older age groups. Anatomical variations and the presence of incomplete fissures were statistically higher in the pneumonia-positive group, while the difference was not statistically significant for accessory fissures. Mean tracheal area and right main bronchus angle were statistically higher in the pneumonia-positive group compared to the negative patients. The right lung was more involved than the left in terms of both zonal and total lung involvement. When the presence of comorbidity was assessed, 59 patients (35.75%) were found to have comorbidity. Hypertension, diabetes mellitus and cardiovascular disease were significantly higher among comorbidities in the pneumonia-positive group. The regression model showed that hypertension was associated with a 3.75-fold increase in COVID-19 pneumonia in test positive cases. Conclusion: Anatomical lung variations and incomplete fissures were observed more frequently in the COVID-19 pneumonia cases, independent of other comorbidities. We believe that there are anatomical variables that can be used to identify those predisposed to pneumonia in RT-PCR test positive cases.

Does Cardiac Computed Tomography In Patients With A Vascular Ring Add Diagnostic Value? Correlation Of Airway Narrowing With Symptoms And Utility Of Tracheal Area Measurements

Does Cardiac Computed Tomography In Patients With A Vascular Ring Add Diagnostic Value? Correlation Of Airway Narrowing With Symptoms And Utility Of Tracheal Area Measurements

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.

Risk factor evaluation of cuff pressure of >30 cmH2O to stop air leakage during mechanical ventilation: A prospective observational study.

The commonly recommended endotracheal tube cuff pressure is 20-30 cmH2O. However, some patients require a cuff pressure of >30 cmH2O to prevent air leakage. The study aims to determine the risk factors that contribute to the endotracheal tube cuff pressure of >30 cmH2O to prevent air leakage. A multi-centre prospective observational study. Eligible patients undergoing mechanical ventilation in the intensive care unit of three hospitals between March 2020 and July 2022 were included. The endotracheal tube cuff pressure to prevent air leakage was determined using the minimal occlusive volume technique. The patient demographics and clinical information were collected. A total of 284 patients were included. Among these patients, 55 (19.37%) patients required a cuff pressure of >30 cmH2O to prevent air leakage. The multivariate logistic regression results revealed that the surgical operation (odds ratio [OR]: 8.485, 95% confidence interval [CI]: 1.066-67.525, p = 0.043) was inversely associated with the endotracheal tube cuff pressure of >30 cmH2O, while the oral intubation route (OR: 0.127, 95% CI: 0.022-0.750, p = 0.023) and cuff inner diameter minus tracheal area (OR: 0.949, 95% CI: 0.933-0.966, p < 0.001) were negatively associated with the endotracheal tube cuff pressure of >30 cmH2O. Therefore, a significant number of patients require an endotracheal tube cuff pressure of ＞30 cmH2O to prevent air leakage. Several factors, including the surgical operation, intubation route, and difference between the cuff inner diameter and tracheal area at the T3 vertebra, should be considered when determining the appropriate cuff pressure during mechanical ventilation.

Ultralow-Dose Dynamic Expiratory CT and Repeated Imaging Enhance Evaluation for Tracheomalacia.

This study aims to determine if a novel imaging protocol (ultralow-dose dynamic expiratory computed tomography [CT] with repeated imaging) identifies tracheomalacia (TM) more reliably than traditional dynamic tracheal CT. We performed a retrospective evaluation of 184 consecutive ultralow-dose dynamic CTs for TM during 2017. The protocol obtains images during 1 inspiration and 2 forced expirations. Tracheal narrowing during both expirations (airway narrowing [percentage] during first dynamic expiration CT [DE1], airway narrowing [percentage] during second dynamic expiration CT [DE2]) was reported as a percentage of inspiratory area. We identified maximum narrowing of each patient's sequence (maximum narrowing [percentage] on either dynamic expiration CT [DEmax] = greatest narrowing of DE1 or DE2) and compared DE1, DE2, and DEmax in individual studies and between patients. Outcomes included frequency of TM, tracheal narrowing, and severity. Reliability was assessed by comparing tracheal area narrowing and TM grade. There was significantly more airway narrowing using 2 expiratory image acquisitions. Average DEmax tracheal area was 12% narrower than DE1 alone and 21% worse than DE2 alone (both P < 0.001). Using DEmax, TM was diagnosed 35% more often than DE1 alone and 31% more often than DE2 alone ( P < 0.001). DEmax identified more severe distribution of TM compared with DE1 or DE2 alone ( P < 0.001). Reliability between DE1 and DE2 was good for tracheal narrowing and moderate for TM grade. The mean effective radiation dose was 2.41 millisievert (mSv) for routine inspiration CT and 0.07 mSv for each dynamic expiration CT (total effective radiation, 2.55 mSv). Dynamic expiration CT with 2 expiratory image acquisitions enhanced evaluation of TM, minimally increased radiation dose, and should be considered as a noninvasive screening option.

Biodegradable polydioxanone stents: histologic and structural effects in an experimental model of tracheal stenosis.

To evaluate the biologic impact of polydioxanone (PDO) stenting in an animal model of inflammatory tracheal stenosis (TS). Additionally, to compare these results with those obtained in the same model without a stent and after placing one PDO stent in a healthy trachea. 40 adult NZ rabbits were distributed into 3 groups: Group A, 8 animals with a healthy trachea and a PDO stent; group B, 17 rabbits with a TS and no stent; and group C, 15 animals with TS and a PDO stent. Histopathological studies included Masson's trichrome staining for submucosal fibrosis and Safranin O to assess structural integrity of cartilage. Morphometric analyses were performed in the 3 groups. Stent placement was successful in every case. Histological studies did not show a significant increase in tracheal wall collagen area and cartilage structure was not modified in those rabbits with a PDO stent, even in a TS scenario. Stent implantation permitted recovery of normal tracheal lumen levels in the TS model. PDO stenting in the normal trachea and in a model of TS neither caused increase in the collagen matrix nor modification of the cartilaginous support. Additionally, radial force exhibited by PDO stents was effective in restoring normal tracheal lumen when placed in a stenotic lesion. These findings suggest that they may be safe and useful in the setting of an acquired TS.

МИКРОБИОЦЕНОЗЫ ПРИ ОСТРОЙ КАТАРАЛЬНОЙ БРОНХОПНЕВМОНИИ ТЕЛЯТ

The purpose of the study is to conduct intravital diagnostics of calves with acute catarrhal bronchopneumonia using bronchoalveolar lavage samples and a detailed study of microbiocenoses from the collected contents. Objectives: development of a technique for intravital collection of bronchoalveolar lavage in calves with bronchopneumonia; study of the microbial landscape in calves with bronchopneumonia, characteristics of isolated microorganisms and their associations. The object of the study is calves aged 1–3 months, sick with acute catarrhal bronchopneumonia (n = 37). Pathological bronchoalveolar lavage was collected transnasally from the tracheal bifurcation area using sterile silicone catheters into sterile test tubes. Bacteriological studies were conducted using generally accepted methods at the Scientific and Educational Resource Center (SERC) Pharmacy of the People's Friendship University of Russia. As a result of the studies, 115 microorganisms of 13 species, classified into 9 genera, were isolated. The majority of isolates – 71 (61.7 %) were classified as gram-negative microorganisms. Staphylococcus aureus, Mannheimia haemolytica, Escherichia coli, Pasteurella multocida, Klebsiella pneumoniae, Streptococcus pyogenes and Klebsiella ozaenae were most often isolated from pathological material in cases of bronchopneumonia in calves. Isolates of E. coli were most often represented by O8, O26 and O111 serotypes. Of the 115 microorganisms that initiated bronchopneumonia in calves, the majority – 75 (65.2 %) cultures – had pathogenic properties. Retrospective analysis of microbial associations showed that most often the development of acute catarrhal bronchopneumonia in calves is caused by associations of opportunistic microorganisms, which included from 2 to 5 pathogens. Moreover, associations that included three members were most often isolated – 21 (56.8 %) and two members – 8 (21.6 %). Thus, in acute catarrhal bronchopneumonia of calves, microbiocenoses are formed in the inflammation focus, which can include various variations of opportunistic microorganisms.

Characteristics of anesthetic and surgical tactics in treatment of a patient with a giant thyroid mass in a cancer center (clinical case)

This paper describes an example of radical surgical treatment of a patient with a giant retrosternal goiter complicated by compression of the organs of the neck and mediastinum. Considering all the risks and possible complications, we should take into account the fact that enlarged thyroid (T) body with retrosternal location can cause displacement and stenosis of the trachea and esophagus, and dislocation of large vessels and nerves of the mediastinum. This anatomical specificity is an imminent threat to successful treatment, and it also carries a certain risk of asphyxia and sudden death of the patient. In this clinical case, radical surgical treatment in this patient included sequential mobilization in two pleural cavities, and then the total removal of T through the traditional surgical access. The anesthetic complexity to support the surgical intervention involved both difficult intubation due to tracheal stenosis, and also the required separate ventilation of the lungs to visualize anatomical structures and mobilize a multinodular formation in two pleural cavities. Standard methods of artificial lung ventilation could be ineffective and even dangerous in this case due to the location and size of the tumor. We focused our attention on high-frequency ventilation (HFV), the best method of respiratory support during surgeries for tracheal and bronchial pathologies. The main task of the anesthetic team in this clinical case was to prevent the development of hypercapnia and hypoxia during intubation of the stenotic tracheal segment, and then adequate ventilation of the lungs with reduced area of proper gas exchange due to bilateral surgical pneumothorax. Thus, the full treatment was carried out due to the only safe method of compensating lung ventilation with anesthesia by HFV. The applied HFV method creates an adequate gas exchange in the lungs due to the small ventilation volume and high frequency of respiratory cycles per minute. HFV both prevented the development of threatening complications during intubation of the stenotic tracheal area and ensured an adequate gas exchange during successive thoracoscopic stages of thyroid tumor mobilization.

CT-based quantification of trachea shape to detect invasion by thyroid cancer.

This study aims to develop a CT-based method for quantifying tracheal shape and evaluating its ability to distinguish between cases with or without tracheal invasion in patients with thyroid carcinoma. A total of 116 quantitative shape features, including 56 geometric moments and 60 bounding shape features, were defined. The tracheal lumen was semi-automatically defined with a CT threshold of less than - 500 HU. Three contiguous slices with the 1st, 2nd, and 3rd smallest trachea lumen areas were contiguously selected, and the appropriate number of slices to be included was determined. Fifty-six patients with differentiated thyroid carcinoma (DTC) invading the trachea and 22 patients with DTC but without invasion were retrospectively included. A receiver operating characteristic (ROC) curve was applied to select the representative shape features and determine the optimal threshold. 23.3%, 25.9%, and 24.1% of the features displayed an area under the ROC curve (AUC) ≥ 0.800 when derived from 1, 2, and 3 slices, respectively. Calculating feature values from two slices with the 1st and 2nd smallest tracheal lumen area were considered appropriate. Six final features, including 3 geometric moments and 3 bounding shape features, were selected to determine the tracheal invasion status of DTC and displayed AUCs of 0.875-0.918, accuracies of 0.821-0.891, sensitivities of 0.813-0.893, and specificities of 0.818-0.932, outperforming the visual evaluation results. Geometric moments and bounding shape features can quantify the tracheal shape and are reliable for identifying DTC tracheal invasion. The selected features quantified the extent of tracheal deformity in DTC patients with and without tracheal invasion. Six geometric features provide a non-invasive, semi-automated evaluation of the tracheal invasion status of thyroid cancer. • A novel method for quantifying tracheal shape using 56 geometric moments and 60 bounding shape features was developed. • Six features identify tracheal invasion by thyroid carcinoma. • The selected features quantified the extent of tracheal deformity in differentiated thyroid carcinoma patients with and without tracheal invasion.

Pediatric airway compression in aortic arch malformations: a multidisciplinary approach.

Aortic arch malformations (AAMs) should be suspected in the presence of persistent respiratory symptoms despite medical treatment or feeding problems at the pediatric age. We report a descriptive cohort of patients with AAMs and the local management protocol applied. A total of 59 patients with AAM were retrospectively reviewed. Three groups were identified: double aortic arch (DAA), group 1; complete vascular ring (non-DAA), group 2; and anomalous origin of the innominate artery (IA), group 3. Prenatal diagnosis was available for 62.7% of the patients. In all, 49.2% of children were symptomatic. There was a significantly different prevalence of respiratory symptoms within the three groups: 73.7% in group 1, 24.2% in group 2, and 100% in group 3 (p-value: <0.001). Surgery was considered in the presence of symptoms in patients with DAA and in those with reduction of the tracheal section area greater than 50%. A total of 52.5% of the patients underwent surgical repair (median age 6 months). The median follow-up interval was 21.9 months. Respiratory symptoms improved in most symptomatic patients. No specific protocols are available for the management of patients with AAMs. Conservative treatment seems to be reasonable for asymptomatic patients or those with airway stenosis less than 50%. A close follow-up is necessary to identify early patients who become symptomatic.

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.

Design and fabrication of silicone-silica nanocomposites airway stent

Introduction: Due to the COVID-19 pandemic in recent years, many patients after extubation had stenosis in all tracheal areas because of long-term intubation. Therefore, tracheal stenosis in these patients is benign and can be treated using silicone stents, and many patients need silicone stents during recovery. A silicone stent is an artificial support that plays a significant role in managing airway obstruction.Methods: This research aims to fabricate an optimal silicone stent reinforced with Nanosilica by vacuumed injection molding. Materials-based nanocomposites are made of rtv2 silicone with 1wt%, 3wt%, and 5wt% of hydrophilic and hydrophobic Nanosilica particles. Hardness, tensile, and hydrophobicity properties have been performed for the experimental characterization of the nanocomposites.Results and Discussion: The uniform distribution of nanoparticles in the silicone matrix has been confirmed using SEM images. Adding Nano-silica increases hardness and tensile strength and improves the silicone matrix’s mechanical properties. Also, the addition of nanoparticles changes the surface hydrophobicity properties and roughness. Although the presence of nanoparticles improves the mechanical properties, it also reduces the transparency and increases the viscosity. Our results show that adding 1wt%. Hydrophobic Nano-silica improves nanocomposites’ mechanical properties and preserves transparency and viscosity (mold-ability) for stent construction. Adding 3wt%. Hydrophilic Nano-silica improves mechanical and hydrophobic properties, but moldability is not easy. Finally, the fabricated nanocomposite airway stents were successfully placed on the sheep trachea in the pilot animal study.

Effectıveness of Curcumın on Tracheal Anastomosıs Created in the Rat Model

Objective: We aimed to investigate the effect of curcumin on tracheal wound healing in the anastomosis model following tracheal incision in rats. Methods: Twenty-one healthy male Wistar Albino rats were included in the study. A horizontal incision was made between the 2nd-3th rings of the rat trachea and damage was created in the inner tracheal mucosa. Tracheal incision area was sutured and anastomosis was performed. Rats were divided into three groups. Ringer was given to the first group, corticosteroids to the 2nd group, and curcumin to the 3rd group for 28 days. The rats were sacrificed on the 28th day and the tracheal anastomosis line samples were sent for histological examination. Wound healing parameters, tracheal lumen width, wall thickness, and stenosis index were evaluated. Results: Statistically significant difference was detected in tracheal lumen width and wall thickness in the curcumin group (p&amp;lt;0.05). Statistically significant differences were observed in the curcumin group in parameters of inflammation, collagen production and fibrosis. (p&amp;lt;0.05). Conclusion: It is important to prevent the formation of tracheal stenosis, which is difficult to treat in clinical practice. Desired results cannot be achieved in the side-effect profile of some medical drugs used in this regard. We found the positive effect of Curcumin in the prevention of stenosis following tracheal injury.

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.

Prognosis prediction of the mean tracheal air column area in COVID-19 patients

Aim: SARS-CoV-2 infection frequently affects the lungs, it can also cause severe inflammation in the lower respiratory tract, leading to tracheal damage. We aimed to investigate the relationship between the mean tracheal air column and COVID-19.Material and Method: Chest computed tomography scans of COVID-19 patients treated in an intensive care unit between June 1st, 2020 and October 1st 2022 were retrospectively evaluated. The air column area of the trachea was measured and the effect of the values obtained on mortality and length of stay in the intensive care unit for patients COVID-19 was examined.Results: We found that an increase in the mean tracheal air column increased mortality by 1.218 times. We also determined that an increase in the mean area of the tracheal air column increased the length of stay in the intensive care unit. Furthermore, we showed that advanced age and an increase in the length of stay in the intensive care unit were factors that increased mortality.Conclusion: Tracheomegaly is a poor prognostic factor in COVID-19 disease and is easily diagnosed with CT.

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.

Delayed tracheal perforation post total thyroidectomy

Delayed tracheal perforation is a rare occurrence post thyroidectomy. We present a 72 year-old female patient that underwent elective total thyroidectomy and right upper parathyroidectomy, with bilateral central lymph node dissection and modified radical neck dissection. The post-operative period was complicated by high-risk pre-morbid status and multiple failed extubations, in addition to ischaemic tracheal areas visualised on the bronchoscopy on post-operative day (POD) 8, with subsequent computerised tomography (CT) scan showing anterior neck collections and perforation. A tracheal perforation involving the anterolateral wall (2nd and 3rd rings) was repaired surgically, followed by a tracheostomy. Suspicion of tracheal injuries should always be considered if patient fail to liberate from the mechanical ventilation post-operatively, warranting prompt conservative and/or surgical management. Potential devascularisation, secondary to diathermy-induced injury and pressure exerted by endotracheal tube cuff onto already weakened/friable trachea, should be considered as probable aetiological factors.

Association between surgical tracheostomy and chronic tracheal stenosis: A retrospective, single-center study.

Tracheal stenosis is a major complication of tracheostomy. Accordingly, anesthesiologists tend to select a smaller endotracheal tube (ETT) than usual for patients with a prior tracheostomy history, regardless of the presence or absence of respiratory symptoms. However, it likely comes from our trial and error, not scientific evidence. Therefore, in this study, we retrospectively examined the association between traditional surgical tracheostomy and tracheal stenosis as assessed by transverse computed tomography (CT). Patients who underwent surgery for head and neck cancer from January 2010 to December 2013, with a temporary tracheostomy closed within a couple of months, were included. Exclusion criteria were tracheostoma before surgery, permanent tracheostomy, or insufficient CT follow-up. Transverse CT slices were measured 2 cm above and below the tracheostomy site (0.5 cm/slice for a total of 9 slices). The minimum cross-sectional tracheal area and horizontal and vertical diameters in transverse CT slices were compared before (baseline: BL), 6 months (6M) and 12 months (12M) after tracheostomy. Tracheal stenosis was defined as a decrease in the minimum cross-sectional tracheal area compared to BL. Of 112 patients, 77 were included. The minimum tracheal area was significantly decreased at 6M and 12M compared to BL (BL: mean 285 [SD 68] mm2, 6M: 267 [70] mm2, P < 0.01 vs. BL, 12M: 269 [68] mm2, P < 0.01 vs. BL), and the localization was predominantly at or above the tracheostomy site at 6M and 12M. Tracheal stenosis was identified in 55 patients at 6M and in 49 patients at 12M without any respiratory symptoms. With regard to horizontal and vertical diameter, only horizontal diameter was significantly decreased at 6M and 12M compared to BL (BL: 16.8 [2.4] mm, 6M: 15.4 [2.7] mm, P < 0.01 vs. BL, 12M: 15.6 [2.8] mm, P < 0.01 vs. BL). Conventional surgical tracheostomy was associated with a decreased horizontal diameter of the trachea. It resulted in a decreased cross-sectional tracheal area in more than one-half of the patients; however, no patient complained of any respiratory symptoms. Therefore, even without respiratory symptoms, prior tracheostomy causes an increased risk of tracheal stenosis, and using a smaller ETT than usual could be reasonable.