The Compromised Airway: Tumors, Strictures, and Tracheomalacia

Molecular Biology and Therapeutic Targets of Primitive Tracheal Tumors: Focus on Tumors Derived by Salivary Glands and Squamous Cell Carcinoma

Primary tracheal tumors are rare, constituting approximately 0.1-0.4% of malignant diseases. Squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) account for about two-thirds of these tumors. Despite most primary tracheal cancers being eligible for surgery and/or radiotherapy, unresectable, recurrent and metastatic tumors may require systemic treatments. Unfortunately, the poor response to available chemotherapy as well as the lack of other real therapeutic alternatives affects the quality of life and outcome of patients suffering from more advanced disease. In this condition, target therapy against driver mutations could constitute an alternative to chemotherapy, and may help in disease control. The past two decades have seen extraordinary progress in developing novel target treatment options, shifting the treatment paradigm for several cancers such as lung cancer. The improvement of knowledge regarding the genetic and biological alterations, of major primary tracheal tumors, has opened up new treatment perspectives, suggesting the possible role of biological targeted therapies for the treatment of these rare tumors. The purpose of this review is to outline the state of knowledge regarding the molecular biology, and the preliminary data on target treatments of the main primary tracheal tumors, focusing on salivary-gland-derived cancers and squamous cell carcinoma.

Common causes of congenital stridor in infants

Stridor is a high-pitched respiratory sound that signals upper airway obstruction. It can be encountered by clinicians in a variety of clinical settings and requires a team-based, interdisciplinary approach. Early recognition is crucial, as the differential diagnosis can be broad, and causes range from benign to life-threatening. This article reviews the most commonly encountered causes of chronic congenital stridor in infants, focusing on the diagnostic approach, pathophysiology, clinical presentation, and management strategies.

Overview of malignant tracheal tumors

Malignant airway tumors present particular challenges for surgeons, namely: to distinguish symptoms from those of the more frequent benign airway diseases; to separate metastatic disease from the uncommon primary tumors; and to consider curative resection in appropriate candidates. Here, we present a critical review of tracheal malignant obstruction, focusing on the evaluation of a patient with malignant airway tumor, patient selection for resection and the predictors of long-term survival. The new development in primary tracheal tumors is an old story, that of making physicians aware that resection rates in epidemiologic studies remain low, mainly because opportunities for resection are missed.

Rapid response in a critical lung adenocarcinoma presenting as large airway stenoses after receiving stent implantation and sequential rebiopsy guided ALK inhibitor therapy: a case report

Airway stent implantation can improve the symptoms of airway stenosis caused by a malignant tumor immediately. However, stent implantation is only a palliative therapy and disease will quickly progress without subsequent treatment. Targeted therapy can provide accurate etiological treatment for patients with critical lung cancer who cannot receive chemotherapies. In our clinic, we encountered a 50-year-old male presenting with stage IV lung adenocarcinoma. He failed both the first-line and second-line chemotherapies and suffered severe complex left and right main bronchial stenoses caused by tumor invasion. An emergency stent was implanted to relieve dyspnea symptoms. At nearly the same time, he was detected to have an ALK gene fusion mutation upon rebiopsy and subsequently began crizotinib therapy. A short time later his obstructed airway returned to normal and lesions in the lung were miraculously reduced. This case indicates that the combination of stent implantation and real-time rebiopsy guided targeted therapy brings a new hope for patients with critical lung cancer.

Management of tracheomalacia in an infant with Tetralogy of Fallot

Most infants with tracheomalacia do not need specific therapy as it usually resolves spontaneously by the age of 1–2 years. Severe forms of tracheomalacia characterized by recurrent respiratory infections require active treatment which includes chest physiotherapy, long term intubation or tracheostomy. Aortopexy seems to be the treatment of choice for secondary and even primary forms of severe tracheomalacia. Itentails tracking and suturing the anterior wall of the aorta to the posterior surface of the sternum. Consequently, the anterior wall of the trachea is also pulled forward preventing its collapse. A 3-month-old girl baby who was on ventilatory support for 2 months due to severe tracheomalacia associated with a cyanotic congenital heart disease underwent intracardiac repair and aortopexy along with Lecompte's procedure as all the conservative measures to wean off the ventilator failed. The baby was extubated on the third post-operative day and the post-operative period was uneventful.

A surprising cause of wheezing in a morbidly obese patient: a case report

A typical patient with chronic obstructive pulmonary disease has small airway disease, which often responds to bronchodilators. If the patient is obese, he or she may be further compromised and not tolerate being in the supine position. We present a case of a patient with history of chronic obstructive pulmonary disease and obstructive sleep apnea with acute renal failure and urosepsis scheduled for an emergent debridement of Fournier's gangrene. In this patient, the fiberoptic intubation was performed in semi-Fowler's position, and tracheomalacia was observed.

Viability and proliferation of rat MSCs on adhesion protein-modified PET and PU scaffolds

In 2011, the first in-man successful transplantation of a tissue engineered trachea-bronchial graft, using a synthetic POSS-PCU nanocomposite construct seeded with autologous stem cells, was performed. To further improve this technology, we investigated the feasibility of using polymers with a three dimensional structure more closely mimicking the morphology and size scale of native extracellular matrix (ECM) fibers. We therefore investigated the in vitro biocompatibility of electrospun polyethylene terephthalate (PET) and polyurethane (PU) scaffolds, and determined the effects on cell attachment by conditioning the fibers with adhesion proteins. Rat mesenchymal stromal cells (MSCs) were seeded on either PET or PU fiber-layered culture plates coated with laminin, collagen I, fibronectin, poly-D-lysine or gelatin. Cell density, proliferation, viability, morphology and mRNA expression were evaluated. MSC cultures on PET and PU resulted in similar cell densities and amounts of proliferating cells, with retained MSC phenotype compared to data obtained from tissue culture plate cultures. Coating the scaffolds with adhesion proteins did not increase cell density or cell proliferation. Our data suggest that both PET and PU mats, matching the dimensions of ECM fibers, are biomimetic scaffolds and, because of their high surface area-to-volume provided by the electrospinning procedure, makes them per se suitable for cell attachment and proliferation without any additional coating.

Tracheobronchial transplantation with a stem-cell-seeded bioartificial nanocomposite: a proof-of-concept study

BACKGROUND

Tracheal tumours can be surgically resected but most are an inoperable size at the time of diagnosis; therefore, new therapeutic options are needed. We report the clinical transplantation of the tracheobronchial airway with a stem-cell-seeded bioartificial nanocomposite.

METHODS

A 36-year-old male patient, previously treated with debulking surgery and radiation therapy, presented with recurrent primary cancer of the distal trachea and main bronchi. After complete tumour resection, the airway was replaced with a tailored bioartificial nanocomposite previously seeded with autologous bone-marrow mononuclear cells via a bioreactor for 36 h. Postoperative granulocyte colony-stimulating factor filgrastim (10 μg/kg) and epoetin beta (40,000 UI) were given over 14 days. We undertook flow cytometry, scanning electron microscopy, confocal microscopy epigenetics, multiplex, miRNA, and gene expression analyses.

FINDINGS

We noted an extracellular matrix-like coating and proliferating cells including a CD105+ subpopulation in the scaffold after the reseeding and bioreactor process. There were no major complications, and the patient was asymptomatic and tumour free 5 months after transplantation. The bioartificial nanocomposite has patent anastomoses, lined with a vascularised neomucosa, and was partly covered by nearly healthy epithelium. Postoperatively, we detected a mobilisation of peripheral cells displaying increased mesenchymal stromal cell phenotype, and upregulation of epoetin receptors, antiapoptotic genes, and miR-34 and miR-449 biomarkers. These findings, together with increased levels of regenerative-associated plasma factors, strongly suggest stem-cell homing and cell-mediated wound repair, extracellular matrix remodelling, and neovascularisation of the graft.

INTERPRETATION

Tailor-made bioartificial scaffolds can be used to replace complex airway defects. The bioreactor reseeding process and pharmacological-induced site-specific and graft-specific regeneration and tissue protection are key factors for successful clinical outcome.

FUNDING

European Commission, Knut and Alice Wallenberg Foundation, Swedish Research Council, StratRegen, Vinnova Foundation, Radiumhemmet, Clinigene EU Network of Excellence, Swedish Cancer Society, Centre for Biosciences (The Live Cell imaging Unit), and UCL Business.

Severe tracheobronchomalacia after prolonged intubation of multitrauma patient

Tracheobronchomalacia is a condition with significant morbidity with many etiologies including iatrogenic ones and should be considered in critically ill ventilated trauma patients. We present a case of a multitrauma patient who had difficulty weaning from the ventilator after prolonged intubation followed by tracheostomy tube placement. We describe her presentation, diagnosis, and management provide and as well a discussion of the condition.