Segmental Bronchi Research Articles

Mastery learning guided by AI is superior to directed self-regulated learning in flexible bronchoscopy training - an RCT.

Simulation-based training has proven effective for learning flexible bronchoscopy. However, no studies have tested the efficacy of training towards established proficiency criteria i.e., mastery learning (ML). We wish to test the effectiveness of ML compared to Directed Self-Regulated Learning (DSRL) on novice bronchoscopists' end-of-training performance. In a standardized simulated setting, novices without prior bronchoscopy experience trained using an artificial intelligence (AI) guidance system that automatically recognizes the bronchial segments. They were randomized into two groups: the ML group and the DSRL group. The ML group trained until they completed two procedures meeting the proficiency targets: 18 inspected segments, 18 structured progressions, <120 seconds procedure time. The DSRL group trained until they no longer perceived any additional benefits from training. Both groups then did a finalizing test, without the AI-guidance enabled. 24 participants completed the study, with 12 in each group. Both groups had a high mean number of inspected segments (ML=17.2 segments, DSRL=17.3 segments, P=.85) and structured progressions (ML=15.5 progressions, DSRL=14.8 progressions, P=.58), but the ML group performed the test procedure significantly faster (ML=107 seconds, DSRL=180 seconds, P<.001). The ML did not spend significantly longer time training (ML=114 minutes, DSRL=109 minutes, P=.84). ML is a very efficient training form allowing novice trainees to learn how to perform a thorough, systematic, and quick flexible bronchoscopy. ML does not require longer time spent training compared to DSRL, and we therefore recommend training of future bronchoscopists by this method.

Case Report: Aspirated Airway Foreign Body Mimicking Endobronchial Mass: A Diagnostic Challenge

Abstract Introduction/Objective Despite advancements in imaging modalities, identifying retained foreign bodies within the lung remains arduous. Detecting small foreign bodies is crucial as they can serve as a focal point for subsequent infections. Initial assessments may mimic malignancy. Herein, we present a case of a retained foreign body masquerading as an endobronchial mass, accompanied by unilateral pleural effusion and persistent hypoxia. Subsequent bronchoscopy showed a pearly white endobronchial mass partially obstructing the segmental bronchus at the posterior basal segment of the right lower lobe of lung with accompanying right pleural effusion and atelectasis. Methods/Case Report This is a 58-year-old male with history of hypertension, deep vein thrombosis, transient ischemic attack, and a recent motor vehicle accident with blunt chest trauma. He had a thoracic spinal cord transection with grade III blunt thoracic aortic injury, developed anasarca, hypoxia, right pleural fluid requiring multiple thoracentesis, and right sided hemothorax requiring massive transfusion protocol. Subsequent evaluations, including bronchoscopic transbronchial forceps biopsies and bronchial wash and pleural fluid cytologic examinations showed no malignant cells. Repeat bronchoscopy was concerning for enlarging mass and obstruction. Bronchoscopy almost 2 months after MVA revealed an endobronchial foreign body (tooth) lodged in the left lower lobe of lung posterior segment. Results (if a Case Study enter NA) N/A Conclusion While aspiration of foreign bodies into the tracheobronchial tree is not uncommon especially in children, foreign bodies, particularly teeth, are rare in adults. Bronchial foreign body aspiration may occur in trauma, with diagnosis typically relying on history and physical examination. Detection remains challenging despite imaging advancements, with implications including infection nidus formation. In our case, delayed diagnosis highlights the importance of considering unusual etiologies in persistent pulmonary pathology. Retrospective imaging analysis and CT findings suggested a foreign body, emphasizing the utility of imaging in suspected cases. Prompt surgical intervention is crucial to prevent complications such as recurrent infections.

A 47-Year-old Asian female with tracheobronchial space-occupying lesions caused by chronic lymphocytic leukemia

Case presentationA 47-year-old Asian woman was admitted with worsening chest tightness and dyspnea for 10 days. Computed tomography (CT) showed changes in the trachea and segmental bronchi. Pulmonary function results suggestive of severe obstructive ventilatory dysfunction. Bronchoscopic findings showed the presence of multiple nodular lesions in the patient’s trachea and left and right main bronchi. Bronchoscopic biopsy, lymph node biopsy and bone marrow aspiration flow cytometry test results led to a definitive diagnosis of chronic lymphocytic leukemia (CLL), staged as Binet stage B and Rai stage 2.

Clinical characteristics of 29 cases of pulmonary mucormycosis treated with and without surgery

Objective: To analyze the clinical characteristics of patients with pulmonary mucormycosis treated with and without surgery. Methods: This was a single-center, retrospective study. We retrieved "pulmonary mucormycosis" from the electronic medical records of China-Japan Friendship Hospital between 2016 and 2022. A total of 29 patients with pulmonary mucormycosis were collected. There were 19 males and 10 females with a median age of 49 (47, 67) years. Mann-Whitney U test, χ² test, Kaplan-Meier curve and log-rank test were used to compare the differences between groups. Results: The most common underlying disease was diabetes (19, 65.5%). The most frequent imaging findings were consolidation (25, 86.2%) and nodule or mass (21, 72.4%). Bronchial stenosis (16, 55.2%), obstruction by fungal plugs (18, 62.1%), pseudomembranous necrotizing bronchitis (19, 65.5%) were common. Treatment strategies were developed by the multi-disciplinary team (MDT). Among 16 patients who did not undergo surgery, 10 had bilateral multifocal lesions and 6 had unifocal lesions. All patients received antifungal therapies, and surgeries were performed in 13 (44.8%) patients. Patients who underwent surgery had numerically lower in-hospital mortality (15.4% vs. 31.3%, P=0.410). Involvement of unilateral multiple lesions was more common in patients who underwent surgeries (6/13 vs. 1/16, P=0.019). Patients who underwent surgery were more likely to have lobar and segmental bronchial involvement (13/13 vs. 9/16, P=0.007). A total of 15 patients underwent mNGS, 14 (93.3%) had positive results. Performing metagenomic next generation sequencing for diagnosis shortened the time from disease onset to diagnosis (log-rank P=0.014). Conclusion: Metagenomic next-generation sequencing aided early diagnosis. The patients who underwent surgery included unilateral multiple lesions and visualisation of endobronchial abnormalities on lobar or segmental bronchus in unilateral lung.

Delayed 3D IR FLASH for airway imaging in children: more than myocardial fibrosis assessment

BackgroundTo investigate the ability of a delayed respiratory-navigated, electrocardiographically-gated three-dimensional inversion recovery-prepared flash low angle shot (3D IR FLASH) sequence to evaluate the lower airways in children undergoing routine cardiovascular magnetic resonance (CMR). MethodsThis retrospective study included pediatric patients (0-18 years) who underwent clinical CMR where a delayed 3D IR FLASH sequence was performed between July 2020 and April 2021. The airway image quality and extent of lower airway visibility was graded by two blinded readers using a four-point ordinal scale (0-3). Lower airway anatomical variants and abnormalities were recorded. Results180 patients were included with a median age of 11.7 (4.6-15.3) years. 51/180 (28%) were under general anesthesia (GA). Overall, the median grading of airway image quality was 3 (2-3) and extent of lower airway visibility was 3 (3-3). Interrater agreement was almost perfect (κ = 0.867 and κ = 0.956, respectively). Image quality correlated with extent of lower airway visibility (r = 0.62, p < 0.01). Delayed 3D IR FLASH was able to characterize the segmental bronchi in 137/180 (76%) and lobar bronchi in 172/180 (96%) of patients. Lower airway abnormalities were identified in 37/180 (21%) of patients and in 33/129 (26%) with congenital heart disease (CHD). Identified abnormalities included tracheobronchial branching anomalies in 6/180 (3%), abnormal tracheobronchial situs in 6/180 (3%), and extrinsic vascular compression in 25/180 (14%). ConclusionsDelayed 3D IR FLASH has excellent performance for evaluation of the lower airway anatomy and can simultaneously assess for myocardial late gadolinium enhancement. Lower airway abnormalities are not infrequently seen in children undergoing routine CMR for CHD.

Artificial intelligence for automatic and objective assessment of competencies in flexible bronchoscopy.

Bronchoscopy is a challenging technical procedure, and assessment of competence currently relies on expert raters. Human rating is time consuming and prone to rater bias. The aim of this study was to evaluate if a bronchial segment identification system based on artificial intelligence (AI) could automatically, instantly, and objectively assess competencies in flexible bronchoscopy in a valid way. Participants were recruited at the Clinical Skills Zone of the European Respiratory Society Annual Conference in Milan, 9th-13th September 2023. The participants performed one full diagnostic bronchoscopy in a simulated setting and were rated immediately by the AI according to its four outcome measures: diagnostic completeness (DC), structured progress (SP), procedure time (PT), and mean intersegmental time (MIT). The procedures were video-recorded and rated after the conference by two blinded, expert raters using a previously validated assessment tool with nine items regarding anatomy and dexterity. Fifty-two participants from six different continents were included. All four outcome measures of the AI correlated significantly with the experts' anatomy-ratings (Pearson's correlation coefficient, P value): DC (r=0.47, P<0.001), SP (r=0.57, P<0.001), PT (r=-0.32, P=0.02), and MIT (r=-0.55, P<0.001) and also with the experts' dexterity-ratings: DC (r=0.38, P=0.006), SP (r=0.53, P<0.001), PT (r=-0.34, P=0.014), and MIT (r=-0.47, P<0.001). The study provides initial validity evidence for AI-based immediate and automatic assessment of anatomical and navigational competencies in flexible bronchoscopy. SP provided stronger correlations with human experts' ratings than the traditional DC.

Techniques for intraoperative identification and confirmation of segmental bronchus in minimally invasive segmentectomy

Techniques for intraoperative identification and confirmation of segmental bronchus in minimally invasive segmentectomy

BCNet: Bronchus Classification via Structure Guided Representation Learning.

CT-based bronchial tree analysis is a key step for the diagnosis of lung and airway diseases. However, the topology of bronchial trees varies across individuals, which presents a challenge to the automatic bronchus classification. To solve this issue, we propose the Bronchus Classification Network (BCNet), a structure-guided framework that exploits the segment-level topological information using point clouds to learn the voxel-level features. BCNet has two branches, a Point-Voxel Graph Neural Network (PV-GNN) for segment classification, and a Convolutional Neural Network (CNN) for voxel labeling. The two branches are simultaneously trained to learn topology-aware features for their shared backbone while it is feasible to run only the CNN branch for the inference. Therefore, BCNet maintains the same inference efficiency as its CNN baseline. Experimental results show that BCNet significantly exceeds the state-of-the-art methods by over 8.0% both on F1-score for classifying bronchus. Furthermore, we contribute BronAtlas: an open-access benchmark of bronchus imaging analysis with high-quality voxel-wise annotations of both anatomical and abnormal bronchial segments. The benchmark is available at link1.

Determinant of Bronchoarterial Ratio in a Patient Undergoing Computed Tomography Chest

Background: Respiratory diseases pose a significant challenge in Nepali clinical settings due to elevated smoking rates and environmental risks. This study explores the structural changes in conditions such as asthma, chronic obstructive pulmonary disease, and bronchiectasis, utilizing noninvasive multi-detector computed tomography to assess airway remodeling. Despite conflicting western literature on bronchoarterial ratios, this research emphasizes the importance of evaluating these ratios in the Nepalese context for predicting airway disease severity. Materials and Methods: The cross-sectional study conducted at Nobel Medical College and Teaching Hospital involved 129 participants aged over 20 undergoing chest computed tomography. It aimed to measure the bronchoarterial ratio and investigate its associations with age, gender, smoking history, and altitude of residence. Bronchoarterial ratios was calculated using averaged short-axis diameters of the right apical and right posterior basal segmental bronchi, excluding the left lung due to motion artifacts. Results: Analysis indicated a Mean Bronchoarterial Ratio of 0.823 (SD 0.151), with the apical and basal segment BARs at 0.832 (SD 0.148) and 0.814 (SD 0.153), respectively. Notably, individuals aged over 65 who were smokers exhibited a significant increase in BAR. Additionally, a higher altitude of residence demonstrated a significant correlation with the Bronchoarterial ratio in the apical lung segment. Conclusion: This study provides valuable insights into the bronchoarterial ratio within the Nepalese population, considering age, gender, smoking history, and altitude of residence. The findings underscore the potential relevance of these ratios in conditions involving airway remodeling, contributing to the understanding of respiratory diseases in this specific demographic.

Tracking Ovine Pulmonary Adenocarcinoma Development Using an Experimental Jaagsiekte Sheep Retrovirus Infection Model.

Ovine pulmonary adenocarcinoma (OPA) is an infectious, neoplastic lung disease of sheep that causes significant animal welfare and economic issues throughout the world. Understanding OPA pathogenesis is key to developing tools to control its impact. Central to this need is the availability of model systems that can monitor and track events after Jaagsiekte sheep retrovirus (JSRV) infection. Here, we report the development of an experimentally induced OPA model intended for this purpose. Using three different viral dose groups (low, intermediate and high), localised OPA tumour development was induced by bronchoscopic JSRV instillation into the segmental bronchus of the right cardiac lung lobe. Pre-clinical OPA diagnosis and tumour progression were monitored by monthly computed tomography (CT) imaging and trans-thoracic ultrasound scanning. Post mortem examination and immunohistochemistry confirmed OPA development in 89% of the JSRV-instilled animals. All three viral doses produced a range of OPA lesion types, including microscopic disease and gross tumours; however, larger lesions were more frequently identified in the low and intermediate viral groups. Overall, 31% of JSRV-infected sheep developed localised advanced lesions. Of the sheep that developed localised advanced lesions, tumour volume doubling times (calculated using thoracic CT 3D reconstructions) were 14.8 ± 2.1 days. The ability of ultrasound to track tumour development was compared against CT; the results indicated a strong significant association between paired CT and ultrasound measurements at each time point (R2 = 0.799, p < 0.0001). We believe that the range of OPA lesion types induced by this model replicates aspects of naturally occurring disease and will improve OPA research by providing novel insights into JSRV infectivity and OPA disease progression.

Clinical observation of three-dimensional reconstruction in thoracoscopic segmental pneumonectomy.

Accurately identifying the branches of pulmonary segmental vessels and bronchi, as well as adjacent structures, and determining the spatial location of lesions within pulmonary segments, are major challenges for thoracic surgeons. The application of three-dimensional reconstruction technology holds promise in addressing this issue. To evaluate the clinical value of three-dimensional reconstruction in thoracoscopic segmental surgery. Seventy-seven patients who underwent thoracoscopic segmental surgery combined with three-dimensional reconstruction at our hospital from January 1, 2020, to August 31, 2023, were retrospectively analyzed. Preoperative chest enhanced CT scans were conducted, and MIMICS software aided in reconstructing DICOM format original data for patients with pulmonary nodules to facilitate intraoperative nodule localization. Accurate segmental pneumonectomy was performed by comparing preoperative anatomical identification of target segmental arteries, veins, and bronchi, with surgical details and postoperative outcomes recorded, including intraoperative pulmonary resection distribution, operation time, blood loss, chest tube drainage, extubation time, hospital stay, and complications. Following preoperative three-dimensional reconstruction, successful segmental lung surgeries were performed, predominantly with single segmental resection (92.2%), and a minority with combined segmentectomy (7.8%). Median operation time was 130225 minutes, with intraoperative blood loss at 70100 mL and postoperative chest tube drainage at 347 mL (159690mL). Median extubation time and hospital stay were 4 days and 7 days, respectively. Complications within the 3-month follow-up affected 11.7% of cases, including persistent pulmonary leakage (7.1%), pulmonary infection (4.3%), atelectasis (4.3%), and pleural effusion (1.4%), with no fatalities. Preoperative 3D reconstruction can help the operator to perform safe, efficient and accurate thoracoscopic segmental pneumonectomy, which is worth popularizing in clinic.

Identification of the Segmental Bronchus Using Indocyanine Green During Thoracoscopic Segmentectomy

Identification of the Segmental Bronchus Using Indocyanine Green During Thoracoscopic Segmentectomy

Successful treatment of cicatricial stenosis of the main, intermediate and upper lobe bronchi of the right lung complicated by total lung atelectasis in an infant: a clinical case

BACKGROUND: The authors present a rare clinical case of stenosis of the main, intermediate and upper lobe bronchi of the right lung complicated by total lung atelectasis in an infant. They discuss issues of complex disease diagnostics, analyze X-ray and bronchological images, assess outcomes after multidisciplinary approach in the treatment of a premature baby as well as analyze data of catamnestic observation. CLINICAL CASE DESCRIPTION: Girl T., one of monochorionic diamniotic twins, was born at 27 week gestation in 2021 with weight at birth 825 grams, Apgar score 4/5. Since her birth, she had artificial lung ventilation due to her deep immaturity and developed severe respiratory distress syndrome. At the age of 19 days, total atelectasis of the right lung was diagnosed in the child as a result of stenosis formation in the main, intermediate and upper lobe bronchi which was confirmed by clinical and radiological findings. A probable etiology of acquired stenosis is consequences of prolonged intubation under insufficiently formed cartilaginous framework. Chlamydial infection, detected in the child, could also support inflammatory process in the bronchi. The child was examined with the following instruments: radiography, multispiral computed tomography-angiography of the thoracic cavity, bronchofibroscopy, echocardiography. Laboratory tests: polymerase chain reaction of blood and sputum for herpes viruses type 1–6, mycoplasma, ureaplasma, Chlamydia pneumonia; blood enzyme immunoassays — antibodies to viruses of Herpesviridae type 1–6, Chlamydia trachomatis. Conservative therapy provided only temporal improvement; atelectasis was relapsing. At the age of 5 months and 20 days, the child underwent bronchoplasty with resection of damaged areas of the bronchi. Further, age-related diameter of the bronchial lumen was maintained by the staged bougienage. Catamnestic observation lasted for 3 years. Late timing of surgical intervention is explained by severe problems in a deeply premature and immature child that required immediate treatment (intraventricular hemorrhages, hydrocephalus, retinopathy, etc.). Effective surgical treatment (bronchoplasty), active growth of lung tissue at the first year of life as well as reasonable rehabilitation allowed to obtain good long-term outcomes. By the age of 1 year 2 months, normalization of right lung airiness was achieved. Currently, there is a slight reduction in right lung volume. Multispiral computed tomography-angiography revealed a few cylindrical bronchoectases in the segmental and subsegmental bronchi of the upper and middle lobes of the right lung which do not have clinical equivalents yet. The child is under pulmonologist's observation and management. CONCLUSION: A multidisciplinary approach to the treatment of complicated patient's state and high compensatory capabilities of neonatal and infantile periods have promoted the restoration of normal lung aeration and functioning after long-lasting lung atelectasis

Artificial intelligence-assisted quantitative CT analysis of airway changes following SABR for central lung tumors

IntroductionUse of stereotactic ablative radiotherapy (SABR) for central lung tumors can result in up to a 35% incidence of late pulmonary toxicity. We evaluated an automated scoring method to quantify post-SABR bronchial changes by using artificial intelligence (AI)-based airway segmentation. Materials and methodsCentral lung SABR patients treated at Amsterdam UMC (AUMC, internal reference dataset) and Peter MacCallum Cancer Centre (PMCC, external validation dataset) were identified. Patients were eligible if they had pre- and post-SABR CT scans with ≤ 1 mm resolution. The first step of the automated scoring method involved AI-based airway auto-segmentation using MEDPSeg, an end-to-end deep learning-based model. The Vascular Modeling Toolkit in 3D Slicer was then used to extract a centerline curve through the auto-segmented airway lumen, and cross-sectional measurements were computed along each bronchus for all CT scans. For AUMC patients, airway stenosis/occlusion was evaluated by both visual assessment and automated scoring. Only the automated method was applied to the PMCC dataset. ResultsStudy patients comprised 26 from AUMC, and 33 from PMCC. Visual scoring identified stenosis/occlusion in 8 AUMC patients (31 %), most frequently in the segmental bronchi. After airway auto-segmentation, minor manual edits were needed in 9 % of patients. Segmentation for a single scan averaged 83sec (range 73–136). Automated scoring nearly doubled detected airway stenosis/occlusion (n = 15, 58 %), and allowed for earlier detection in 5/8 patients who had also visually scored changes. Estimated rates were 48 % and 66 % at 1- and 2-years, respectively, for the internal dataset. The automated detection rate was 52 % in the external dataset, with 1- and 2-year risks of 56 % and 61 %, respectively. ConclusionAn AI-based automated scoring method allows for detection of more bronchial stenosis/occlusion after lung SABR, and at an earlier time-point. This tool can facilitate studies to determine early airway changes and establish more reliable airway tolerance doses.

Intraoperative view of the operating field showing the visualization of the luminescence with near-infrared fluorescence of the two segmental bronchi after bronchoscopic identification during a robotic right upper lobe posterior segmentectomy (S2).

Intraoperative view of the operating field showing the visualization of the luminescence with near-infrared fluorescence of the two segmental bronchi after bronchoscopic identification during a robotic right upper lobe posterior segmentectomy (S2).

Intraoperative view of selective clamping with the endostapler of the right upper lobe posterior segmental bronchus and re-ventilation of the lung showing inflation of the anterior and apical segments during a robotic right upper lobe posterior segmentectomy (S2).

Intraoperative view of selective clamping with the endostapler of the right upper lobe posterior segmental bronchus and re-ventilation of the lung showing inflation of the anterior and apical segments during a robotic right upper lobe posterior segmentectomy (S2).

Intraoperative bronchoscopic view of clamped segmental bronchus of the lingula showing permeability of the apical trisegmental bronchus.

Intraoperative bronchoscopic view of clamped segmental bronchus of the lingula showing permeability of the apical trisegmental bronchus.

Intraoperative view of the isolation of the right upper lobe posterior segmental bronchus, ventilation of the lung, clamping of the bronchus with endostapler and deflation of the lung showing an inflated segment 2 during a robotic right upper lobe posterior segmentectomy (S2).

Intraoperative view of the isolation of the right upper lobe posterior segmental bronchus, ventilation of the lung, clamping of the bronchus with endostapler and deflation of the lung showing an inflated segment 2 during a robotic right upper lobe posterior segmentectomy (S2).

A Case of Quadrivial Pattern of Right Upper Lobe Bronchus

Abstract The knowledge of the tracheobronchial tree is fundamental for a bronchoscopist, especially for diagnostic, therapeutic, and surgical options that are under consideration. Among all lobes, the right upper lobe (RUL) has a relatively high incidence of tumor and airspace diseases. Most bronchial anomalies are on the right side. Bifurcation is the most common anatomical variation. Quadrification has a very low prevalence. We report the case of a 54-year-old male who came with complaints of hemoptysis and showed a quadrivial type of bronchial division of RUL during a bronchoscopic examination after which three-dimensional computed tomography bronchography showed a supernumerary lateral or axillary segment bronchus. Awareness of this variant may explain otherwise confusing findings and its clinical implication is important for every pulmonologist.

Different anatomical variations in the anterior segment of the right upper lung

During a routine physical examination three years ago, a 47-year-old woman received a diagnosis of a nodule in her right upper lung. Since then, she has been regularly attending outpatient clinic appointments for follow-up. Over time, the nodule has shown gradual growth, leading to a suspicion of lung cancer. Through the use of enhanced CT imaging, a three-dimensional reconstruction was performed to examine the bronchi and blood vessels in the patient’s chest. This reconstruction revealed several variations in the anatomy of the anterior segment of the right upper lobe. Specifically, the anterior segmental bronchus (B3) was found to have originated from the right middle lung bronchus. Additionally, the medial subsegmental artery of the anterior segmental artery (A3b) and the medial segmental artery (A5) were observed to share a common trunk. As for the lateral subsegmental artery of the anterior segmental artery (A3a), it was found to have originated from the right inferior pulmonary trunk. Furthermore, the apical subsegmental artery of the apical segmental artery (A1a) and the posterior segmental artery (A2) were found to have a shared trunk.