A lesson in plasticity: a 74-year-old man with plastic bronchitis

Recycling plastic: diagnosis and management of plastic bronchitis among adults

Plastic bronchitis is a rare, underdiagnosed and potentially fatal condition. It is characterised by the formation and expectoration of branching gelatinous plugs that assume the shape of the airways. These airway plugs differ from the allergic mucin that characterises allergic bronchopulmonary aspergillosis and mucoid impaction of the bronchi. Plastic bronchitis is most often encountered in the paediatric population following corrective cardiac surgery, such as the Fontan procedure. It also occurs in adults. Plastic bronchitis in adults is rare, heterogeneous in its aetiology, and can lead to respiratory distress or even life-threatening airway obstruction. Plastic bronchitis in adulthood should not be overlooked, particularly in patients with chronic inflammatory lung diseases. This review presents current understanding of the presentation, aetiology, pathogenesis, pathology and management of plastic bronchitis in adults.

Food for Thought: Dietary Intervention in a Rare Cause of Severe Ventilatory Failure

Plastic bronchitis is a rare condition characterised by endobronchial cast formation. We report the case of a 53-year-old women who deteriorated following an elective bronchoscopy procedure. She developed refractory ventilatory failure and required repeated bronchoscopy, which identified thick tenacious casts as the cause of her airway compromise. She did not respond to conventional therapies including endoscopic clearance, mucolytic therapy and nebulised tissue plasminogen activator (TPA). Total parenteral nutrition and a fat-free enteral diet were instituted while the patient was on extracorporeal membrane oxygenation (ECMO), which led to substantial improvement in her condition and demonstrated the importance of dietary strategies in this case.

LEARNING POINTS

Plastic bronchitis can rarely present in adults with acute ventilatory failure and life-threatening airway obstruction.Although there are no established guidelines on management, dietary intervention (e.g., a fat-free diet) should be strongly considered as a therapeutic option.Extracorporeal membrane oxygenation (ECMO) is feasible and should be considered in plastic bronchitis with airway compromise.

Pulmonary lymphatic vessel morphology: a review

Our understanding of lymphatic vessels has been advanced by the recent identification of relatively specific lymphatic endothelium markers, including Prox-1, VEGFR3, podoplanin and LYVE-1. The use of lymphatic markers has led to the observation that, contrary to previous assumptions, human lymphatic vessels extend deep inside the pulmonary lobule, either in association with bronchioles, intralobular arterioles or small pulmonary veins. Pulmonary lymphatic vessels may thus be classified into pleural, interlobular (in interlobular septa) and intralobular. Intralobular lymphatic vessels may be further subdivided in: bronchovascular (associated with a bronchovascular bundle), perivascular (associated with a blood vessel), peribronchiolar (associated with a bronchiole), and interalveolar (in interalveolar septa). Most of the intralobular lymphatic vessels are in close contact with a blood vessel, either alone or within a bronchovascular bundle. A minority is associated with a bronchiole, and small lymphatics are occasionally present even in interalveolar septa, seemingly independent of blood vessels or bronchioles. The lymphatics of the interlobular septa often contain valves, are usually associated with the pulmonary veins, and connect with the pleural lymphatics. The large lymphatics associated with bronchovascular bundles have similar characteristics to pleural and interlobular lymphatics and may be considered conducting vessels. The numerous small perivascular lymphatics and the few peribronchiolar ones that are found inside the lobule are probably the absorbing compartment of the lung responsible for maintaining the alveolar interstitium relatively dry in order to provide a minimal thickness of the air-blood barrier and thus optimize gas diffusion. These lymphatic populations could be differentially involved in the pathogenesis of diseases preferentially involving distinct lung compartments.