Miscellaneous

Pills and Capsules: There are various factors that promote the aspiration of pills and capsules including (but not limited to) the motion of placing them into the oral cavity, the state of airway re exes in the subject (i.e. neurological disease,

age, etc.), as well as the quantity and frequency of medication regimens which tend to be more prevalent in the elderly population. When evaluating pill aspiration, it is important to evaluate its obstructive properties, as well as its early and late in ammatory potential. Technically, any pill has the potential to be aspirated. There are well-­

Fig. 40.10  Right lower lobe obstructed by green plastic cylinder, part of a cleaning tool at a dentist offce

Fig. 40.11  Tooth that was aspirated and bronchoscopically retrieved

Fig. 40.12  Multiple broncholiths retrieved from a single patient

known sequelae related to aspiration of specifc medications such as iron supplementation, potassium preparations, and activated charcoal.

Iron pill aspiration is a well-recognized problem. Any medication containing ferrous sulfate (FeSO4), when aspirated, has a caustic effect on the bronchial mucosa secondary to its acidic pH (usually <3). This leads to a local in ammatory cascade of effects including acute mucosal damage, which can lead to the formation of granulomas and fbrosis and eventually, airway stenosis [30–32]. Further specifcs of iron pill aspiration will be discussed in-depth later in this chapter.

Potassium preparations are also very well associated with local in ammatory effects when aspirated. Of the potassium-based formulations, potassium chloride (KCL) is the most commonly aspirated preparation. Due to the hyperosmolar properties of KCL, it leads to mucosal irritation with additional erosive properties to the airway [33]. Similar to ferrous sulfate, late effects can result in airway stenosis. Enteric-coated KCL preparations take time to dissolve and may initially present with airway obstruction.

Activated charcoal is reported to be aspirated in approximately 2.3% of all patients receiving it for gastric emptying indications [34]. Although charcoal is biologically inert and non-absorbable, it is immunogenic, and that can cause a local in ammatory response within the airways. Bronchospasm, airway obstruction (due to in ammatory response), pneumonitis, and acute

respiratory distress syndrome (ARDS) have all been reported with charcoal aspiration [33].

Other medications that are associated with similar in ammatory response include nortriptyline, metformin, pomegranate supplements, barium sulfate, magnesium oxide (Fig. 40.13a, b), and alendronate. While technically not a medication (but are administered similar to oral medications), endoscopic capsules (pill camera) used in diagnostic gastrointestinal evaluation have also been aspirated into the airway [35]. As endoscopic capsules are inorganic, they do not dissolve and act more as obstructive foreign bodies (Fig. 40.14a–d). While extremely rare, aspiration occurs more commonly in elderly patients, who may or may not have a history of swallowing dysfunction.

Stents: While airway stents are used in the treatment of airway obstruction, it is well known among bronchoscopists that stents migrate. Airway stent migration rates have been reported between 4.6% and 17% [36, 37]. Migration of airway stents can occur due to inappropriate choice of stent in relation to airway size, but can also be a result of successful treatment of the underlying etiology for stent requirement. For example, stents are deployed for the management of malignant central airway obstruction

and after successful treatment of tumor, there may be shrinkage or resolution of the initial malignant obstruction. The response to therapy may lead to stent migration because of the lack of airway support on the outer surface of the stent. Additionally, stents used for benign disease in conditions such as tracheal and bronchial stenosis, similar response to therapy and/or excessive coughing may lead to inadvertent stent migration. Airway stents are also known to promote bronchial secretions with the risk of developing airway obstruction due to tenacious secretions. While secretions are not foreign bodies, airway stents obstructed with mucus can present in a similar manner.

Esophageal stents have also been implicated in FB airway obstruction. Although esophageal stent migrations are associated with distal esophageal/gastric migrations [38], there have been reports of acute airway obstruction from proximal migration of esophageal stents with occlusion of the glottis [39]. There have also been case reports of esophageal stents migrating through the posterior membrane of the trachea leading to severe acute airway obstruction and asphyxiation [40].

Photodynamic Therapy (PDT): PDT is a photo-ablative therapy used as an adjunct treat-

Fig. 40.14  An aspirated endoscopic capsule (pill camera). White arrows are pointing toward the capsule in the radiologic studies. (a) Posterior–anterior chest plain flm.

(b) Lateral chest plain flm. (c) Bronchoscopic image of capsule in the right mainstem bronchus. (d) Endoscopic capsule after retrieval

ment of central airway NSCLC malignant disease not amenable to further standard treatment options. Routine practice is to perform a followup­ bronchoscopy 48–72 h post-procedure to clear necrotic debris induced by the therapy. In some instances, this debris can slough off and can obstruct the central airways. There have been reports of acute airway obstruction in the immediate hours after completion of PDT [41]. Similar to other incidences, tumor slough is typically not

thought of as a true FB, yet its clinical presentation mirrors that of other foreign bodies.

Other Miscellaneous Foreign Bodies: Other rare causes of FB aspiration include everyday world objects (Fig. 40.15a–c), erosion of grafted rib material during tracheoplasty, endobronchial suture material from bronchial stumps status post-lobectomy/pneumonectomy, Alloderm© patches and migrated gauze packing from nasal and oropharyngeal indications.