Fractal analysis of concurrently prepared latex rubber casts of the bronchial and vascular systems of the human lung

Fractal geometry (FG) is a branch of mathematics that instructively characterizes structural complexity. Branched structures are ubiquitous in both the physical and the biological realms. Fractility has therefore been termed nature's design. The fractal properties of the bronchial (airway) system, the pulmonary artery and the pulmonary vein of the human lung generates large respiratory surface area that is crammed in the lung. Also, it permits the inhaled air to intimately approximate the pulmonary capillary blood across a very thin blood–gas barrier through which gas exchange to occur by diffusion. Here, the bronchial (airway) and vascular systems were simultaneously cast with latex rubber. After corrosion, the bronchial and vascular system casts were physically separated and cleared to expose the branches. The morphogenetic (Weibel's) ordering method was used to categorize the branches on which the diameters and the lengths, as well as the angles of bifurcation, were measured. The fractal dimensions ( D F ) were determined by plotting the total branch measurements against the mean branch diameters on double logarithmic coordinates (axes). The diameter-determined D F values were 2.714 for the bronchial system, 2.882 for the pulmonary artery and 2.334 for the pulmonary vein while the respective values from lengths were 3.098, 3.916 and 4.041. The diameters yielded D F values that were consistent with the properties of fractal structures (i.e. self-similarity and space-filling). The data obtained here compellingly suggest that the design of the bronchial system, the pulmonary artery and the pulmonary vein of the human lung functionally comply with the Hess–Murray law or ‘the principle of minimum work’.

Right-Sided Approach for Segmental Resection of the Left Main Bronchus—Technical Considerations

Carcinoids of the left main bronchus are rare tumors of the bronchial system and patients often present with dyspnea, asthma-like symptoms, and pneumonia. Gold standard for therapy of carcinoids is surgical resection, but the surgical approach for segmental resection and anastomosis of the left main bronchus is a matter of discussion. With a left-sided approach the access to the bronchus is blocked by the aortic arch and the pulmonary vein. If a right-sided approach is performed, the problem of ventilation during resection and anastomosis of the bronchus occurs. We present a surgical approach from the right side using intraoperative extracorporeal membrane oxygenation to assure oxygen supply for resection of a typical carcinoid of the left main stem bronchus, and discuss the current literature.

Evaluation of a bronchoscopy guidance system for bronchoscopy training, a randomized controlled trial

Background Conventional training in bronchoscopy is performed either on patients (apprenticeship model) or phantoms. While the former is associated with increased rate of patient complications, procedure time, and amount of sedation, the latter does not offer any form of feedback to the trainee. This paper presents a study which investigates whether a bronchoscopy guidance system may be a helpful tool for training of novice bronchoscopists. Methods A randomized controlled study with 48 medical students was carried out with two different groups (control and test group, each N = 24). Whereas the control group performed a conventional bronchoscopy on phantom the test group carried out an Electromagnetic Navigation Bronchoscopy (ENB) for tracking of the bronchoscopal tip in the bronchial system. All volunteers had a common task: to perform a complete and systematic diagnostic bronchoscopy within 10 min. Results The test group examined significantly more lobes than the control group (p = 0.009). Due to the real-time feedback of the system, all students of test group felt more confident having analyzed the entire lung. Additionally, they were unanimous that the system would be helpful during the next bronchoscopy. Conclusions In sum, this technology may play a major role in unsupervised learning by improving accuracy, dexterity but above all by increasing the confidence of novices, students as well as physicians. Due to good acceptance, there may be a great potential of this tool in clinical routine.

Minimally Invasive Treatment of a Bronchobiliary Fistula that Developed Secondary to Chemotherapy-induced Stricturing

A bronchobiliary fistula (BBF) is a rare abnormal communication between the biliary tree and bronchial system. The majority of cases are the result of biliary obstruction or injury, with the major symptomatology of cough and biliptysis. The initial management of BBFs is variable but aims to decompress the biliary system allowing for diversion and passive healing of the fistula tract. Definitive management is with surgical fistulectomy. New minimally invasive therapeutic approaches utilizing endoscopic or percutaneous methodology have been described with some success. We present the successful treatment of a BBF that developed secondary to chemotherapy-induced biliary stricturing (CIBS) with a novel percutaneous embolization approach using a vascular plug and liquid embolic agent.

Lung Sequestration in an Octogenarian Male

Lung sequestration is a congenital disorder in which the lung parenchyma is not attached to the bronchial system, with blood supply originating from the aorta or various peripheral arteries. It may cause chronic pulmonary infection or bleeding and may require surgical resection. An 80-year-old male was incidentally found to have a paravertebral right thoracic mass. Computed tomography scan with contrast suggested a feeding vessel from the supraceliac aorta and suspicion of a lung sequestration was confirmed on selective angiography. He developed chronic cough, but this was managed symptomatically and no specific treatment, such as surgical resection, was necessary. Lung sequestration in the elderly is a rare condition but should be considered in a patient presenting with stable lung lesions, especially if a feeding artery from the aorta can be identified.

FRACTAL GEOMETRY ENABLES CLASSIFICATION OF DIFFERENT LUNG MORPHOLOGIES IN A MODEL OF EXPERIMENTAL ASTHMA

Animal models represent the basis of our current understanding of the pathophysiology of asthma and are of central importance in the preclinical development of drug therapies. The characterization of irregular lung shapes is a major issue in radiological imaging of mice in these models. The aim of this study was to find out whether differences in lung morphology can be described by fractal geometry. Healthy and asthmatic mouse groups, before and after an acute asthma attack induced by methacholine, were studied. In vivo flat-panel-based high-resolution Computed Tomography (CT) was used for mice's thorax imaging. The digital image data of the mice's lungs were segmented from the surrounding tissue. After that, the lungs were divided by image gray-level thresholds into two additional subsets. One subset contained basically the air transporting bronchial system. The other subset corresponds mainly to the blood vessel system. We estimated the fractal dimension of all sets of the different mouse groups using the mass radius relation (mrr). We found that the air transporting subset of the bronchial lung tissue enables a complete and significant differentiation between all four mouse groups (mean D of control mice before methacholine treatment: 2.64 ± 0.06; after treatment: 2.76 ± 0.03; asthma mice before methacholine treatment: 2.37 ± 0.16; after treatment: 2.71 ± 0.03; p < 0.05). We conclude that the concept of fractal geometry allows a well-defined, quantitative numerical and objective differentiation of lung shapes — applicable most likely also in human asthma diagnostics.

Modern Approaches to Etiopathogenetic Therapy of Broncho-Obstructive Disease in Pediatric Practice

The research of effective methods of treatment of broncho-obstructive diseases is one of the most important questions of the pediatric pulmonology. General clinical manifestations are characterized by attacks of breathlessness, prolonged exhalation, unproductive cough, whistling and noisy breathing sometimes with a help of auxiliary muscles. Often this disease leads to bronchial asthma, obstructive bronchitis, and malformations of the lung and bronchus. In the pathogenesis of bronchial obstruction whilst respiratory infections the main factors are inflammatory infiltration of the bronchial mucosa, its swelling, hypersecretion of viscous mucus and bronchospasm due to hyperactivity of the bronchi of the inflammatory nature. To diagnose this disease it is important to establish the presence or absence of the effectiveness of the protective mechanisms of the body at different hierarchic levels. To protect the respiratory tract from exposure to adverse environmental factors in the process of ontogenesis pro-tective mechanisms formed. The first stage of purification of the bronchial system is mucociliary clearance carried out by the cells of the ciliated epithelial cells and glands that produce bronchial secret. If the cause of the disease is established, the etiotropic and pathogenetic treatment of the underlying disease should be carried out. Of special interest in pediatric pulmonology is the experience of the combined drug Kashnol. It simultaneously affects almost all parts of the pathogenesis of acute and chronic broncho-pulmonary diseases.

Conservative treatment of bronchobiliary fistula evaluated with magnetic resonance imaging

Introduction. Bronchobiliary fistula (BBF) is a pathological communication between the bronchial system and the biliary tree that presents with bilioptysis. Many conditions can cause its development. There is still no optimal therapy for BBF. Conservative treatment is rarely indicated, as was published before in a few cases. Case report. We presented a 71-year-old Caucasian Serbian woman with BBF secondary to previous laparotomy due to multiple echinococcus liver cysts. The diagnosis was established by the presence of bilirubin and bile acids in sputum and magnetic resonance cholangiopancreatography (MRCP). A repeat MRCP performed after conservative procedure, did not reveal fistulous communication. Conclusion. We suggest that in small and less severe fistulas between the biliary and the bronchial tract, conservative treatment may be used successfully, and invasive treatment methods are not needed in all patients.