Clinical anatomy of pulmonary connections in young people.

OBJECTIVE: Aim: To study the clinical anatomy of the pulmonary ligaments of young people. PATIENTS AND METHODS: Materials and Methods: The study was carried out when performing 28 autopsies of young people aged 25 to 44 years. Methods of dissection of chest organocomplexes, macro-microscopy, morphometry and planimetry, and statistical processing were used. The shape and topography of the pulmonary ligaments was assessed, their area, the localization of lymph nodes was examined. RESULTS: Results: The pulmonary ligament is an anatomical formation, which is formed as a result of a combination of leaves of the mediastinal pleura, which, covering the surfaces of the roots of the lungs, descend towards the diaphragm and are located between the mediastinal organs and the lungs. Pulmonary connections on both sides have a few edges: the inner, outer and lower free. The pulmonary ligaments with lower free edges do not pass to the diaphragmatic surface of the pleura, but only with inner ones, which are located on the right along the esophagus, and on the left along the aorta. Pulmonary ligaments on both sides pass into the mediastinal part of the pleura, covering the pericardium. CONCLUSION: Conclusions: There are individual differences between the shape and size of the right and left pulmonary ligaments in males and females. There is no significant difference between the sizes of the right and left pulmonary ligaments, but such dimensions as: the width, the angle of inclination and the ratio of their lower free edge to the lower edge of the lungs are not found in all cases.

Topography of pleural epithelial structure enabled by en face isolation and machine learning.

Pleural epithelial adaptations to mechanical stress are relevant to both normal lung function and parenchymal lung diseases. Assessing regional differences in mechanical stress, however, has been complicated by the nonlinear stress-strain properties of the lung and the large displacements with ventilation. Moreover, there is no reliable method of isolating pleural epithelium for structural studies. To define the topographic variation in pleural structure, we developed a method of en face harvest of murine pleural epithelium. Silver-stain was used to highlight cell borders and facilitate imaging with light microscopy. Machine learning and watershed segmentation were used to define the cell area and cell perimeter of the isolated pleural epithelial cells. In the deflated lung at residual volume, the pleural epithelial cells were significantly larger in the apex (624 ± 247 µm2 ) than in basilar regions of the lung (471 ± 119 µm2 ) (p < 0.001). The distortion of apical epithelial cells was consistent with a vertical gradient of pleural pressures. To assess epithelial changes with inflation, the pleura was studied at total lung capacity. The average epithelial cell area increased 57% and the average perimeter increased 27% between residual volume and total lung capacity. The increase in lung volume was less than half the percent change predicted by uniform or isotropic expansion of the lung. We conclude that the structured analysis of pleural epithelial cells complements studies of pulmonary microstructure and provides useful insights into the regional distribution of mechanical stresses in the lung.

Lymphatic Pathways of the Thorax: Predictable Patterns of Spread.

OBJECTIVE. This article reviews thoracic lymphatic pathways and tributaries, discusses lymphatic anatomic variants and their clinical implications, and emphasizes common patterns of thoracic lymphadenopathy from extrapulmonary malignancies. CONCLUSION. Recognition of common patterns and pathways of thoracic lymphatic drainage can help identify the site of tumor origin and allow a more focused examination of disease extent, both of which are important for disease prognosis and management.

Lymphatic drainage of lung segments in the visceral pleura: a cadaveric study.

PURPOSE: Although peribronchial lymphatic drainage of the lung has been well characterized, lymphatic drainage in the visceral pleura is less well understood. The objective of the present study was to evaluate the lymphatic drainage of lung segments in the visceral pleura. METHODS: Adult, European cadavers were examined. Cadavers with a history of pleural or pulmonary disease were excluded. The cadavers had been refrigerated but not embalmed. The lungs were surgically removed and re-warmed. Blue dye was injected into the subpleural area and into the first draining visceral pleural lymphatic vessel of each lung segment. RESULTS: Twenty-one cadavers (7 males and 14 females; mean age 80.9 years) were dissected an average of 9.8 day postmortem. A total of 380 dye injections (in 95 lobes) were performed. Lymphatic drainage of the visceral pleura followed a segmental pathway in 44.2% of the injections (n = 168) and an intersegmental pathway in 55.8% (n = 212). Drainage was found to be both intersegmental and interlobar in 2.6% of the injections (n = 10). Lymphatic drainage in the visceral pleura followed an intersegmental pathway in 22.8% (n = 13) of right upper lobe injections, 57.9% (n = 22) of right middle lobe injections, 83.3% (n = 75) of right lower lobe injections, 21% (n = 21) of left upper lobe injections, and 85.3% (n = 81) of left lower lobe injections. CONCLUSION: In the lung, lymphatic drainage in the visceral pleura appears to be more intersegmental than the peribronchial pathway is-especially in the lower lobes. The involvement of intersegmental lymphatic drainage in the visceral pleura should now be evaluated during pulmonary resections (and especially sub-lobar resections) for lung cancer.

Ultrasound-guided pleural access.

Ultrasonography of the thorax has become a more recognized tool in pulmonary medicine, thanks to continuing clinical research that has proven its many valuable roles in the day-to-day management of pulmonary and pleural diseases. Ultrasound examination is a cost-effective imaging modality that permits the pulmonologist to obtain information about the pathologies in the thorax without the risk of exposure to ionizing radiation, providing the examiner with real-time and immediate results. Its ease of use and training along with its portability to the patient's bedside and accurate examination of the pleural space has allowed for safer pleural procedures such as thoracentesis, chest tube placement, tunneled pleural catheter placement, and medical thoracoscopy. In this review, we summarize the technique of chest ultrasonography, compare ultrasound to other frequently used thoracic imaging modalities, and focus on its use in obtaining pleural access while performing invasive pleural procedures.

Surgical treatment of thoracic disc disease via minimally invasive lateral transthoracic trans/retropleural approach: analysis of 33 patients.

Thoracic disc herniations are associated with serious neurological consequences if not treated appropriately. Although a number of techniques have been described, there is no consensus about the best surgical approach. In this study, the authors report their experience in the operative management of patients with thoracic disc herniations using minimally invasive lateral transthoracic trans/retropleural approach. A series of 33 consecutive patients with thoracic disc herniations who underwent anterior spinal cord decompression followed by instrumented fusion through lateral approach is being reported. Demographic and radiographic data, perioperative complications, and clinical outcomes were reviewed. Forty disc levels in 33 patients (18F/15M; mean age, 52.9) were treated. Twenty-three patients presented with myelopathy (69 %), 31 had radiculopathy (94 %), and 31 had axial pain (94 %). Among patients with myelopathy, 14 (42.4 %) had bladder and/or bowel dysfunction. In the last eight cases (24 %), the approach was retropleural instead of transpleural. Patients were followed up for 18.2 months on average. The mean length of hospital stay was 5 days. None of the patients developed neurological deterioration postoperatively. Among 23 patients who had myelopathy signs, 21 (91 %) had improved postoperatively. The mean preoperative visual analog scale pain score, Oswestry Disability Index score, SF-36 PCS, and mental component summary scores were 7.5, 42.4, 29.6, and 37.5 which improved to 3.5, 33.2, 35.5, and 52.6, respectively. Perioperative complications occurred in six patients (18.1 %), all of which resolved uneventfully. Minimally invasive lateral transthoracic trans/retropleural approach is a safe and efficacious technique for achieving adequate decompression in thoracic disc herniations in a less invasive manner than conventional approaches.

Computerized tomographic anatomic relationships of the thoracic paravertebral space.

OBJECTIVES: A wide range of insertion points lateral to the midline are recommended for paravertebral blockade. The authors hypothesized that in a given subject, using an insertion point at the tip of the transverse process has a superficial but consistent depth to the pleura. The authors also hypothesized that for a given insertion point, depths to the pleura are related directly to the patient's anthropomorphic indices. DESIGN: Retrospective observational study. SETTING: Adult tertiary teaching hospital. PARTICIPANTS: Forty-two adult patients. INTERVENTIONS N/A MEASUREMENTS AND MAIN RESULTS: The authors reviewed the computerized tomography scans of 42 adult patients and correlated patients' body mass index, weight, height, and body surface area with skin and transverse process-to-pleura depths at the level of T4, 25 mm from the midline and from the tip of the transverse process. The authors found that the depth to the pleura from the transverse process was significantly deeper at 25 mm lateral to the midline than at the tip of the transverse process (21 mm [4.2mm] v 12 mm [2.7 mm], p<0.0001), and its variability was significantly larger (p = 0.005). The authors found significant correlation between anthropomorphic indices and depths to pleura and transverse process (r>0.8, p<0.0001); however, the prediction bands around their regression lines proved too broad to be clinically useful. CONCLUSIONS: The authors concluded that an insertion point at the tip of the transverse process may provide effective and safer paravertebral blockade and that depth to the pleura cannot be predicted reliably by patients' morphometric profiles.

Surface anatomy of the pulmonary fissures determined by high-resolution computed tomography.

The aim of our study was to describe the surface anatomy of the interlobar fissures using volumetric thin-section high-resolution computed tomography (HRCT). Retrospective assessment of HRCT examinations of 250 patients was performed. The localization of the oblique fissures was marked at three sites: posteriorly at its most superior medial limit, laterally in the midaxillary line, and inferiorly at the junction of the middle and lateral thirds of the hemithorax; posteriorly and laterally, this was to the nearest rib whilst inferiorly the position was described in relation to the diaphragm or chest wall. The localization of the horizontal fissure was marked anteriorly in relation to the nearest rib (or costal cartilage) and posteriorly where it intersected with the oblique fissure (superior, middle, or inferior third). Shapes of the fissures and differences between inspiration and expiration were also documented. Descriptive statistics were used to report the most frequent positions. The most frequent localization of the oblique fissure on the left side was posteriorly at the fourth rib (45%), laterally at the sixth rib (52%), and inferiorly in the anterior third of the hemidiaphragm (60%). The right oblique fissure was located posteriorly at the fifth rib (50%), laterally at the sixth rib (50%), and inferiorly in the anterior third of the hemidiaphragm (71%). The horizontal fissure most commonly originated in the middle third of the oblique fissure (61%) and met the anterior thoracic wall at the level of the fourth rib (51%). The most frequent shape of the left oblique fissure was linear (78%), whereas S-shaped and linear configurations (28% each) were most frequent on the right. No difference was found in the surface markings of the fissures between inspiration and expiration in 90% of cases. The considerable individual variation in the position and shape of the interlobar fissures helps to explain the variable descriptions of their surface anatomy in the literature.

Microscopic anatomy of the pleura.

This article describes the anatomy of the pleura, which is made up of five layers. Blood supply and lymphatics are described, as are pleural fluid, mesothelial cells, and Kampmeier foci.

Anatomy of the pleura.

The pleura is a monolayer of mesothelial cells covering the lung and inner surface of the chest cavity, creating the pleural space. The mesothelial cells rest on a matrix of collagen, elastic fibers, blood vessels, and lymphatics, which allow the lung and chest to expand and contract, protected from friction by the pleural fluid and properties of the mesothelial cells. With a rich blood supply and lymphatic system just deep to the mesothelial layer, the pleura is a dynamic layer protecting the lung and pleural cavity from infection while transmitting the forces of respiration without damage to the underlying lung parenchyma.

Anatomy of the pleura: reflection lines and recesses.

Knowledge of the anatomy of the lines of pleural reflection, triangular ligaments, and pleural recesses is important to thoracic surgeons because their anatomic areas are used daily for radiographic interpretation as well as for the performance of procedures such as chest tube insertion, thoracentesis, and pericardiocentesis. Their knowledge is also important for thoracic surgeons doing surgical procedures such as parietal pleurectomies, extrapleural mobilization and resection of the lungs, and pleuroneumonectomies for destroyed lungs or malignant pleural neoplasms.

Surface anatomy and surface landmarks for thoracic surgery: Part II.

Surface anatomy is an integral part of a thoracic surgeon's armamentarium to assist with the diagnosis, staging, and treatment of thoracic pathology. As reviewed in this article, the surface landmarks of the lungs, heart, great vessels, and mediastinum are critical for appropriate patient care and should be learned in conjunction with classic anatomy.

Correlative anatomy of the pleura and pleural spaces.

Although pleural disorders are commonly encountered in the daily practices of thoracic surgeons, their assessment can be difficult. Being able to correlate normal and abnormal anatomy with imaging characteristics provides additional information that can be useful not only to accurately locate pleuropulmonary lesions but also to characterize abnormalities, such as pleural thickening or malignant processes.

The pleura in health and disease.

A wide variety of local, regional, and systemic diseases may have pleural manifestations. The scope of this pathology encompasses a wide spectrum ranging from minimal inflammatory changes to highly malignant neoplasms. An overview of the normal structure of the pleura is provided, along with the diseases that may be encountered. Pleural specimens from patients with pneumothorax are rarely encountered by pathologists. In contrast, pathologists frequently receive pleural specimens showing evidence of inflammation, repair, or neoplasm. In these circumstances, an awareness of less common (and often clinically highly important) conditions such as epithelioid hemangioendothelioma and primary pleural malignant mesothelioma is essential. Knowledge of the clinical setting (e.g., disease tempo) and radiological picture (e.g., laterality) is often of great value to the pathologist in arriving at a correct diagnosis. Similarly, knowledge of the normal anatomical considerations and familiarity with the expected pleural histopathology for the most clinically relevant pleural diseases are critical assets for pulmonary physicians in providing optimal care for their patients.

Pleural line thickness reference values for preterm and term newborns.

BACKGROUND: In lung ultrasound (LUS), the pleural line is an artifact whose thickness depends on the underlying lung pathology. To date there are no published studies on normal values of pleural line thickness (PLT) in newborns. OBJECTIVE: The aim of our study is to describe normal PLT values in term newborn (TN) and preterm newborn (PTN). METHODS: We recruited eupneic TN and PTN, under 34 weeks of gestation, on their first 24 hours of life. Newborns presenting any respiratory distress since birth were excluded. LUS was performed in four areas: upper anterior, lower anterior, lateral and posterior. At each location, we measured PLT and values where compared. Intraobserver and interobserver agreement were assessed using the intraclass correlation coefficient (ICC), and the kappa coefficient. RESULTS: We included 23 TN with a median birth weight of 3365 g (interquartile range [IQR] 3100-3575 g) and a median gestational age of 39 weeks (IQR, 38-40 weeks). In the PTN group, 23 patients were included with a median birth weight of 1350 g (IQR, 1150-1590 g) and a median gestational age of 31 weeks (IQR, 30-32 weeks). Median PLT values were less than 1 mm, and there were no significant differences between groups at any locations, with the exception of the left lower anterior field (0.79 mm [IQR, 0.72-0.89 mm] vs 0.68 mm [IQR, 0.62-0.72 mm]). Intraobserver agreement was high: consistency ICC 0.77 (95% confidence interval [CI], 0.32-0.92) and absolute ICC 0.78 (95% CI, 0.34-0.93). Interobserver agreement was high for the definition of thin pleural line as less than 1 mm. CONCLUSIONS: TN and asymptomatic PTN have similar PLT values. Overall, PLT in healthy newborns should be less than 1 mm.

Retropleural Thoracic Approach.

The lateral retropleural thoracic approach offers minimally invasive access for the treatment of thoracic spine pathology, specifically thoracic herniated discs. Alternatives to the retropleural approach traditionally included posterolateral or anterior approaches, which carry increased morbidity. The retropleural approach affords lateral access to the thoracic spine that allows for addressing pathology such as herniated discs, corpectomy, tumor, or trauma. This article outlines preoperative workup and planning, intraoperative steps, tips, and postoperative care.

Supine and prone differences in regional lung density and pleural pressure gradients in the human lung with constant shape.

The explanation for prone and supine differences in tissue density and pleural pressure gradients in the healthy lung has been inferred from several studies as compression of dependent tissue by the heart in the supine posture; however, this hypothesis has not been directly confirmed. Differences could also arise from change in shape of the chest wall and diaphragm, and because of shape with respect to gravity. The contribution of this third mechanism is explored here. Tissue density and static elastic recoil were estimated in the supine and prone left human lung at functional residual capacity using a finite-element analysis. Supine model geometries were derived from multidetector row computed tomography imaging of two subjects: one normal (subject 1), and one with small airway disease (subject 2). For each subject, the prone model was the supine lung shape with gravity reversed; therefore, the prone model was isolated from the influence of displacement of the diaphragm, chest wall, or heart. Model estimates were validated against multidetector row computed tomography measurement of regional density for each subject supine and an independent study of the prone and supine lung. The magnitude of the gradient in density supine (-4.33%/cm for subject 1, and -4.96%/cm for subject 2) was nearly twice as large as for the prone lung (-2.72%/cm for subject 1, and -2.51%/cm for subject 2), consistent with measurements in dogs. The corresponding pleural pressure gradients were 0.54 cmH(2)O/cm (subject 1) and 0.56 cmH(2)O/cm (subject 2) for supine, and 0.29 cmH(2)O/cm (subject 1) and 0.27 cmH(2)O/cm (subject 2) for prone. A smaller prone gradient was predicted without shape change of the "container" or support of the heart by the lung. The influence of the heart was to constrain the shape in which the lung deformed.

CT appearances of pleural tumours.

Computed tomography (CT) is the imaging technique of choice for characterizing pleural masses with respect to their location, composition, and extent. CT also provides important information regarding invasion of the chest wall and surrounding structures. A spectrum of tumours can affect the pleura of which metastatic adenocarcinoma is the commonest cause of malignant pleural disease, while malignant mesothelioma is the most common primary pleural tumour. Certain CT features help differentiate benign from malignant processes. This pictorial review highlights the salient CT appearances of a range of tumours that may affect the pleura.