Anatomy of the pleura

Lung-Mimetic Hydrofoam Sealant to Treat Pulmonary Air Leak

Pulmonary air leak is the most common complication of lung surgery, contributing to post-operative morbidity in up to 60% of patients; yet, there is no reliable treatment. Available surgical sealants do not match the demanding deformation mechanics of lung tissue; and therefore, fail to seal air leak. To address this therapeutic gap, a sealant with structural and mechanical similarity to subpleural lung is designed, developed, and systematically evaluated. This "lung-mimetic" sealant is a hydrofoam material that has alveolar-like porous ultrastructure, lung-like viscoelastic properties (adhesive, compressive, tensile), and lung extracellular matrix-derived signals (matrikines) to support tissue repair. In biocompatibility testing, the lung-mimetic sealant shows minimal cytotoxicity and immunogenicity in vitro. Human primary monocytes exposed to sealant matrikines in vitro upregulate key genes (MARCO, PDGFB, VEGF) known to correlate with pleural wound healing and tissue repair in vivo. In rat and swine models of pulmonary air leak, this lung-mimetic sealant rapidly seals air leak and restores baseline lung mechanics. Altogether, these data indicate that the lung-mimetic sealant can effectively seal pulmonary air leak and promote a favorable cellular response in vitro.

Beyond breathing: Systematic review of global chronic obstructive pulmonary disease guidelines for pain management

CONTEXT

Patients with chronic obstructive pulmonary disease (COPD) experience pain as both symptom and comorbidity. There has been no evaluation of the recommendations for pain management in updated clinical practice guidelines (CPGs).

OBJECTIVES

Update the evidence on pain management, determine alignment of pain management recommendations with best-practice, and advocate for optimal pain management in patients with COPD.

METHODS

PubMed, Guideline International Network, Guideline Portal, Agency for Healthcare Research and Quality, National Institute for Healthcare Excellence, Scottish International Guidelines Network, Institute of Medicine, grey literature, national websites, and bibliographies were searched. CPGs available online for stable COPD produced by organizations representing reputable knowledge of COPD management were included. CPGs unavailable online, not translatable into English, or not including techniques within the defined scope were excluded. Researchers performed frequency counts for the verbatim terms "pain," "physical activity," "exercise," "rehabilitation," "physical therap(ist)/(y), "physiotherap(ist)/(y)," recorded context, and collected recommendations for pain management/treatment when present.

RESULTS

Of 32 CPGs, 24 included "pain" verbatim. Of these, 13 included recommendations for pain treatment/management. Common recommendations included opioids, pharmacological management, further medical assessment, and surgical intervention. Two CPGs referred to palliative care, one CPG discussed treating cough, and one discussed massage, relaxation, and breathing.

CONCLUSIONS

Pain management recommendations vary and are not aligned with evidence. Pain should be addressed in patients with COPD, whether directly or indirectly related to the disease. Reduction of variability in pain management and the disease burden is necessary. Pain management should include referrals to providers who can maximize benefit of their services.

The health effects of short fiber chrysotile and amphibole asbestos

The potential toxic effects of short chrysotile and amphibole asbestos fibers with lengths <5 to ∼10 µm have been debated over the years. This stems from the large database of epidemiology, toxicology, and in-vitro studies, each of which often provides different information in understanding and differentiating the effects of short fibers. The epidemiology studies in which the cancer potency estimates were based upon relatively high exposure concentrations provide a conservative assessment that shorter fibers would have little if any effect, especially under controlled exposure or environmental conditions that may occur today. The QSAR models have shown that fiber aspect ratio and Mg content are excellent predictors of cancer potency and that short fibers/particles of amphibole would have no effect. The studies of motor vehicle mechanics and in particular workers who serviced chrysotile containing brakes with the majority of the fibers being short provides evidence that motor vehicle mechanics, including workers who were engaged in brake repair, are not at an increased risk of mesothelioma. Several inhalation toxicology studies clearly differentiated that short chrysotile and amphibole asbestos fibers did not produce a significant carcinogenic effect in the lung or pleural cavity. Because of dosing and lack of sensitivity to biosolubility, in vitro studies can be difficult to interpret; however, a number have differentiated short chrysotile and amphibole asbestos fibers from long fibers. Integral to understanding the importance of fiber length in determining possible health effects is an understanding of the biological and physiological function of the respiratory system. Short asbestos fibers, like innocuous dust, can be cleared through the tracheobronchial ciliated mucous transport, phagocytized by macrophages and cleared via the bronchial tree, and can also be removed through the lymphatic system. While the first two methods can remove them from the lung, with lymphatic transport through one-way valves, fibers are removed from the active area of the lung where the fiber-related disease has been shown to develop and can accumulate in lymphatic sumps and lymph nodes. While short asbestos fibers are present in most occupational or environmental exposures, the large body of studies strongly supports that they do not contribute to the health effects of asbestos exposure.

Anatomical method for rib disconnection during posterior costotransversectomy for paravertebral access to the ventral thoracic spine

Posterior surgical approaches to the thoracic spine are commonly used for degenerative diseases, tumors, trauma, and other operative indications. A posterior approach for access to the paravertebral space is advantageous because it allows for resection of the vertebral body without violating the pleural cavity. Posterior costotransversectomy (PCT) is widely used for this purpose. It involves resection of the rib head after the ligamentous complexes have been disconnected from the transverse process and lateral vertebral body. The current literature provides only vague descriptions of the steps involved in rib disconnection with respect to PCT. A comprehensive knowledge of the anatomical relationships of the ligamentous and soft tissue complexes connecting the rib to the vertebral body is paramount for completing an efficient and safe surgery. This manuscript describes an anatomically directed method for rib disconnection during costotransvrersectomy.

Inflammation of the Pleural Cavity: A Review on Pathogenesis, Diagnosis and Implications in Tumor Pathophysiology

Pleural effusions are a common respiratory condition with many etiologies. Nonmalignant etiologies explain most pleural effusions and despite being nonmalignant, they can be associated with poor survival; thus, it is important to understand their pathophysiology. Furthermore, diagnosing a benign pleural pathology always harbors the uncertainty of a false-negative diagnosis for physicians and pathologists, especially for the group of non-specific pleuritis. This review aims to present the role of the inflammation in the development of benign pleural effusions, with a special interest in their pathophysiology and their association with malignancy.

Palpation of the Respiratory System in Osteopathic Manual Medicine: From the Trachea to the Lungs

There is a lack of published literature in osteopathic manual medicine on how to perform palpation of the lower respiratory tree such as the trachea, main bronchi, and lungs. Several authors have studied the osteopathic effect and respiratory response of palpation but have failed to demonstrate how to perform palpation of the visceral areas involved in breathing, either in the context of a clinical trial or as a case report. This paper reviews the innervation of these anatomical areas, the mechano-metabolic weight of the passage of fluids and air in the respiratory tract, the anatomical topography, and the movements involved in respiration. Drawing from current knowledge, this article illustrates, for the first time, how to place the hands for an effective osteopathic assessment of the tracheal, bronchial, and pulmonary structures. Understanding how to perform palpation of the lower areas is a fundamental tool in the clinic and potential therapy in osteopathic manual medicine.

Temporal evolution of metastatic disease: part I-an in-depth review of the evolution of metastatic disease across diverse spectrum of non-neural solid tumors on serial oncologic imaging studies and relevant practical applications

With improved survival rates of patients with metastatic disease due to continuously evolving multimodality treatment options, radiologists are increasingly interpreting imaging studies from patients with protracted metastatic disease. It is thus crucial for radiologists to have an in-depth understanding of the temporal evolution of metastatic spread and the accompanying findings on imaging studies, to provide accurate interpretation that supports optimal management. A general overview of the evolution of cancer spread on serial imaging studies and common pathways of tumor spread across multiple tumor types and tumor locations is not readily available in radiology literature. The key common pathways of tumor spread across diverse spectrum of tumors relevant to radiologists are summarized in a logical schematic approach which focusses on aiding radiologists to understand the pathways of spread resulting in current sites of metastatic disease involvement and then to potentially predict future sites of metastatic involvement. This article also summarizes the practical applications of this knowledge to the routine oncologic imaging interpretation.

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.

Accessory and Incomplete Lung Fissures: Clinical and Histopathologic Implications

OBJECTIVE

This article reviews the anatomy, histology, and disease processes of pulmonary fissures, with emphasis on clinical implications of accessory and incomplete fissures.

CONCLUSION

Accessory and incomplete pulmonary fissures are often overlooked during routine imaging but can have profound clinical importance. Knowledge of fissure anatomy could improve diagnostic accuracy and inform prognosis for oncologists, interventional pulmonologists, and thoracic surgeons.

Gene therapy for alpha 1-antitrypsin deficiency with an oxidant-resistant human alpha 1-antitrypsin

Alpha 1-antitrypsin (AAT) deficiency, a hereditary disorder characterized by low serum levels of functional AAT, is associated with early development of panacinar emphysema. AAT inhibits serine proteases, including neutrophil elastase, protecting the lung from proteolytic destruction. Cigarette smoke, pollution, and inflammatory cell–mediated oxidation of methionine (M) 351 and 358 inactivates AAT, limiting lung protection. In vitro studies using amino acid substitutions demonstrated that replacing M351 with valine (V) and M358 with leucine (L) on a normal M1 alanine (A) 213 background provided maximum antiprotease protection despite oxidant stress. We hypothesized that a onetime administration of a serotype 8 adeno-associated virus (AAV8) gene transfer vector coding for the oxidation-resistant variant AAT (A213/V351/L358; 8/AVL) would maintain antiprotease activity under oxidant stress compared with normal AAT (A213/M351/M358; 8/AMM). 8/AVL was administered via intravenous (IV) and intrapleural (IPL) routes to C57BL/6 mice. High, dose-dependent AAT levels were found in the serum and lung epithelial lining fluid (ELF) of mice administered 8/AVL or 8/AMM by IV or IPL. 8/AVL serum and ELF retained serine protease–inhibitory activity despite oxidant stress while 8/AMM function was abolished. 8/AVL represents a second-generation gene therapy for AAT deficiency providing effective antiprotease protection even with oxidant stress.

A gene transfer-based therapeutic to deliver oxidant-resistant alpha 1-antitrypsin (AAT) protects mice with AAT deficiency from lung destruction.

Treatment of Pleural Effusions with Nonintubated Video-Assisted Thoracoscopic Surgery

Video-assisted thoracic surgery has considerably improved the care of the thoracic surgical patient. Patients are able to leave the hospital sooner and experience less pain with equal oncologic outcomes when compared with open surgery. Nonintubated thoracic surgery has more recently been applied in the management of both benign and malignant pleural effusions. This article provides the general thoracic surgeon a detailed description on how to manage pleural effusions using video-assisted thoracoscopic surgery in a nonintubated patient. Surgical techniques and pearls are also presented.

The Other Side of the Fascia: The Smooth Muscle Part 1

According to current scientific standards, the fascia is a connective tissue derived from two separate germ layers, the mesoderm (trunk and limbs, part of the neck) and the ectoderm (cervical tract and skull). The fascia has the property of maintaining the shape and function of its anatomical district, but it also can adapt to mechanical-metabolic stimuli. Smooth muscle and non-voluntary striated musculature originated from the mesoderm have never been properly considered as a type of fascia. They are some of the viscera present in the mediastinum, in the abdomen and in the pelvic floor. This text represents the first article in the international scientific field that discusses the inclusion of some viscera in the context of what is considered fascia, thanks to the efforts of our committee for the definition and nomenclature of the fascial tissue of the Foundation of Osteopathic Research and Clinical Endorsement (FORCE).

Lymphatic Pump Manipulation in Patients with Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) show a persistent local and systemic inflammatory pattern which stimulates negative remodeling of the airways. Globally, chronic respiratory disease is the third leading cause of death. One of the rehabilitative strategies used to improve the symptoms of COPD patients is the use of lymphatic pump manipulation; this procedure aims to reduce the concentration of pro-inflammatory substances. However, research results relating to this technique are contradictory. This article reviews the mechanisms that determine lymphatic flow, lymphatic lung anatomy, and the lymphatic response to respiratory pathology. Also highlighted is the manual approach to the mediastinum which can be used to improve the lymphatic and inflammatory response in COPD. Finally, new manual strategies have been discussed with which lymphatic flow in patients with COPD can be improved.

Development of the pulmonary pleura with special reference to the lung surface morphology: a study using human fetuses

In and after the third trimester, the lung surface is likely to become smooth to facilitate respiratory movements. However, there are no detailed descriptions as to when and how the lung surface becomes regular. According to our observations of 33 fetuses at 9–16 weeks of gestation (crown-rump length [CRL], 39–125 mm), the lung surface, especially its lateral (costal) surface, was comparatively rough due to rapid branching and outward growing of bronchioli at the pseudoglandular phase of lung development. The pulmonary pleura was thin and, beneath the surface mesothelium, no or little mesenchymal tissue was detectable. Veins and lymphatic vessels reached the lung surface until 9 weeks and 16 weeks, respectively. In contrast, in 8 fetuses at 26–34 weeks of gestation (CRL, 210–290 mm), the lung surface was almost smooth because, instead of bronchioli, the developing alveoli faced the external surfaces of the lung. Moreover, the submesothelial tissue became thick due to large numbers of dilated veins connected to deep intersegmental veins. CD34-positive, multilayered fibrous tissue was also evident beneath the mesothelium in these stages. The submesothelial tissue was much thicker at the basal and mediastinal surfaces compared to apical and costal surfaces. Overall, rather than by a mechanical stress from the thoracic wall and diaphragm, a smooth lung surface seemed to be established largely by the thick submesothelial tissue including veins and lymphatic vessels until 26 weeks.

Intrapleural Gene Therapy for Alpha-1 Antitrypsin Deficiency-Related Lung Disease

Alpha-1 antitrypsin deficiency (AATD) manifests primarily as early-onset emphysema caused by the destruction of the lung by neutrophil elastase due to low amounts of the serine protease inhibitor alpha-1 antitrypsin (AAT). The current therapy involves weekly intravenous infusions of AAT-derived from pooled human plasma that is efficacious, yet costly. Gene therapy applications designed to provide constant levels of the AAT protein are currently under development. The challenge is for gene therapy to provide sufficient amounts of AAT to normalize the inhibitor level and anti-neutrophil elastase capacity in the lung. One strategy involves administration of an adeno-associated virus (AAV) gene therapy vector to the pleural space providing both local and systemic production of AAT to reach consistent therapeutic levels. This review focuses on the strategy, advantages, challenges, and updates for intrapleural administration of gene therapy vectors for the treatment of AATD.

Chest pain in patients with COPD: the fascia's subtle silence

COPD is a progressive condition that leads to a pathological degeneration of the respiratory system. It represents one of the most important causes of mortality and morbidity in the world, and it is characterized by the presence of many associated comorbidities. Recent studies emphasize the thoracic area as one of the areas of the body concerned by the presence of pain with percentages between 22% and 54% in patients with COPD. This article analyzes the possible causes of mediastinal pain, including those less frequently taken into consideration, which concern the role of the fascial system of the mediastinum. The latter can be a source of pain especially when a chronic pathology is altering the structure of the connective tissue. We conclude that to consider the fascia in daily clinical activity may improve the therapeutic approach toward the patient.

A rare postoperative complication of anterior lower thoracic instrumentation: diaphragmatic laceration with hemothorax

PURPOSE

To highlight the importance of preventing visceral injury due to prominent anterior implants at the spinal column.

METHODS

A 52-year-old man with cord compression was treated with a T9/10 discectomy and instrumented fusion via a right thoracotomy and trans-pleural approach. Postoperatively, he had improved lower limb numbness. However, after a bout of coughing, there was sudden increase in chest drain output, hemodynamic instability and massive fluid collection in the right chest cavity.

RESULTS

Emergency re-exploration of the thoracotomy was performed and a 6 cm laceration of the right postero-medial diaphragm was identified as the bleeding source and was found to be in close proximity with the locking nut of the anterior implants. The laceration was repaired and a soft synthetic patch was used to cover the implants. Postoperatively, the hemothorax resolved and the patient recovered from the neurological deficit.

CONCLUSIONS

Prevention of diaphragmatic injury can be performed using lower profile and less sharp-edged implants. Implant coverage with a soft synthetic material is necessary if unable to perform direct repair of the parietal pleura over the implants.

Gene Therapy for Alpha-1 Antitrypsin Deficiency Lung Disease

Alpha-1 antitrypsin (AAT) deficiency, characterized by low plasma levels of the serine protease inhibitor AAT, is associated with emphysema secondary to insufficient protection of the lung from neutrophil proteases. Although AAT augmentation therapy with purified AAT protein is efficacious, it requires weekly to monthly intravenous infusion of AAT purified from pooled human plasma, has the risk of viral contamination and allergic reactions, and is costly. As an alternative, gene therapy offers the advantage of single administration, eliminating the burden of protein infusion, and reduced risks and costs. The focus of this review is to describe the various strategies for AAT gene therapy for the pulmonary manifestations of AAT deficiency and the state of the art in bringing AAT gene therapy to the bedside.

[Surgical therapy of malignant pleural mesothelioma]

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor disease, which rapidly leads to death if untreated. In Germany the incidence of newly occurring disease is expected to reach a peak in the coming 5 years. An R0 resection for MPM is technically impossible; therefore, the aim of surgical procedures is to achieve the maximum amount of cytoreduction. There are two established surgical techniques for treatment of MPM, extrapleural pneumonectomy and tumor pleurectomy with decortication. The type and extent of surgery are currently controversially discussed. Within multimodal therapy concepts including cytoreductive surgery, long-term remission is possible in selected patients. When choosing the appropriate surgical therapy the high incidence of recurrence has to be borne in mind.

Imaging characteristics of pleural tumours

Abstract

Malignant mesothelioma is doubtless the more known pleural tumour. However, according to the morphology code of the International Classification of Diseases for Oncology (ICD-O), there are several histological types of pleural neoplasms, divided into mesothelial, mesenchymal and lymphoproliferative tumours, that may be misdiagnosed. In this paper we summarise and illustrate the incidence aspects and the clinical, pathological and radiological features of these neoplasms.

Teaching Points

• According to the ICD-O, there are 11 different histological types of pleural neoplasm.

• Imaging, clinical and histopathological aspects of these neoplasms may be overlapping.

• Knowledge of different pleural tumours plays an important role for diagnosis orientation.

Anatomic connections of the diaphragm: influence of respiration on the body system

The article explains the scientific reasons for the diaphragm muscle being an important crossroads for information involving the entire body. The diaphragm muscle extends from the trigeminal system to the pelvic floor, passing from the thoracic diaphragm to the floor of the mouth. Like many structures in the human body, the diaphragm muscle has more than one function, and has links throughout the body, and provides the network necessary for breathing. To assess and treat this muscle effectively, it is necessary to be aware of its anatomic, fascial, and neurologic complexity in the control of breathing. The patient is never a symptom localized, but a system that adapts to a corporeal dysfunction.

Rare pleural tumors

Primary pleural tumors other than mesothelioma account for fewer than 1% of all lung cancers, and consequently they pose diagnostic and management challenges. Their treatment must be targeted toward the specific tumor type and is often quite different from the treatment for mesothelioma or metastases. Despite the best efforts at diagnosing and treating these tumors, the prognosis associated with some of the benign and many of the malignant variants of these tumors remains poor. In this review, we describe the radiologic and pathologic features of the less common primary pleural tumors and propose a diagnostic approach to their evaluation.

[Anatomy, micro-anatomy and physiology of the lymphatics of the lungs and chest wall]

The thoracic lymphatic vessels are pulsating channels which drain actively the fluid of lung parenchyma interstitium and pleural cavities. Their unidirectional valves that avoid reflux of contents, direct the current of fluid to the connection of thoracic duct to subclavian vein or to the thoracic duct itself by these pulsations. The ascending parietal and visceral currents have anastomoses between them. The parietal currents (internal thoracic anteriorly, external axillaries in lateral and paravertebral in posterior) drain the lymph of thoracic wall. Pleural cavities and the visceral currents, drain that of lungs and mediastinal organs. The thoracic duct goes upward in the posterior mediastinum and usually connects to the venous confluent of the left subclavian vein. It receives a part of thoracic lymph and also drains the lymph of trunk and inferior limbs. About a half or two thirds of thoracic duct lymph is originated from liver and intestines. The intestines have the lymph of digestion with the fatty elements, i.e., the chyle.

Pleural disease in the emergency department

Emergency department presentations of pleural-based diseases are common, with severity ranging from mild to life threatening. The acute assessment, diagnosis, and treatment of pleural disease are critical as urgent invasive maneuvers such as thoracocentesis and thoracostomy may be indicated. The emergency physician must have a systematic approach to these conditions that allows for rapid recognition, diagnosis, and definitive management. This article focuses on nontraumatic pleural disease, including diagnostic and treatment considerations of pleural effusion, empyema, primary spontaneous pneumothorax, secondary spontaneous pneumothorax, pediatric pneumothorax, spontaneous hemothorax, and spontaneous tension pneumothorax.