in generating tone. The UES is an additional safety measure in preventing retrograde movement of gastric and esophageal contents. It is mainly stimulated during esophageal distention and gastric re ux, especially when gastric contents reach the distal esophagus.

Epidemiology and Risk Factors

Bronchoscopic FB retrieval accounts for 0.16– 0.33% of all bronchoscopies [19]. Aspiration can occur at any age, but is most commonly found in young children and in the elderly. There tends to be a bimodal distribution for airway FB-associated death with peak incidences at less than 1 year of age and greater than 75 years of age. According to the National Safety Council (NSC) 2019 data, 2500 people died from choking; most, older than 75 years of age. The odds of dying from aspiration of food in the USA is approximately 1 in 3408 [20]. Choking and suffocation related to FB aspiration account for a great proportion of pediatric emergency department (ED) visits on an annual basis. According to the Centers for Disease Control and Prevention, ED visits for nonfatal injuries related to foreign bodies accounted for 371,000 visits in 2018 [21]. Overall, FB aspiration was the fourth leading cause of ED visits for children less than 5 years of age.

There does appear to be a gender bias for aspiration, with males being affected approximately twice as much as females [22–24]. While data is sparse in regard to the impact of geographical and cultural factors on FB aspiration in children, there does appear to be some relationship between the primary language spoken at home and the incidence of aspiration events [25]. In one study, children from non-English speaking households had a signifcantly higher incidence of foreign body aspiration, especially with nuts, compared to English speaking households. As the language spoken in a household is a surrogate marker for cultural background differences, this relationship can be more indicative of dietary-related variances (i.e. promotion of culture-specifc diets with increased presence of nuts), but also cloth-

ing and cultural practice-related differences that exist among different ethnic groups. One example of such cultural risk factors is aspirated scarf pins in Iraqi females, also known as “Hijab syndrome,” retrieved mostly from left tracheobronchial tree [26].

Additional risk factors associated with FB aspiration are advanced age, sedative medications and illicit drug use, neurological disorders, cognitive impairment, trauma with loss of consciousness, dental care, alcohol use, tracheostomy [27].

Types of Foreign Bodies

Any object or material that can ft in the oral cavity has the potential to cause airway obstruction. The most commonly aspirated foreign bodies are nuts, seeds, bones, and dental-related objects [22, 24, 28]. Foreign bodies can be divided into the following categories: organic, inorganic, mineral, and miscellaneous.

Organic

As airway aspiration is usually a byproduct of malfunction of airway re ex mechanisms, one can expect aspiration of edibles to be the most likely offender. Organic material is responsible for the majority of airway FB aspiration cases. The most frequent types of organic aspirations result from nuts and seeds. The most common type of nut aspirated are usually peanuts (Fig. 40.1), but other varieties including: walnuts, almonds, and pistachios can also be seen. The most common seeds aspirated are sun ower seeds. Other types of aspirated organic material include popcorn, fruits, vegetables, and cereals.

Inorganic

Inorganic material can be divided into metallic and plastic materials. Most often implicated metallic foreign bodies are different types of pins and coins (Fig. 40.2a–d). Other aspirated metallic foreign bodies include nails (Fig. 40.3a–c), jew-

Fig. 40.2  Aspirated coin. (a) Low dose CT/chest X-ray with multiple coins in right mainstem bronchus, distal esophagus, and intestine. (b) Coin in right mainstem bron-

chus, lodged against proximal right upper lobe. (c) Retrieved coin. (d) Endobronchial mucosa after coin retrieval

Mineral

Aspiration of teeth comprises the majority of cases under mineral-related foreign bodies (Fig. 40.11). This can occur in relation to trauma, impaired airway re exes (i.e. neurological disease), and during impaired states of consciousness (i.e. sleep, alcohol/drug intoxication, anesthesia, etc.). Bones from meats and fsh are also reported to be aspirated. Another mineral

is glass, which can be from broken glass pipe fragments (used for inhalation of illicit drugs) and from motor vehicle accidents with shattered glass. It is important to understand that even endogenous substances can act as foreign bodies when they produce air ow obstruction with or without gas exchange abnormalities. As an example, broncholiths that have eroded into the intraluminal can act as foreign bodies (Fig. 40.12).

Fig. 40.4  Wire from women’s bra aspirated into the trachea and right mainstem bronchus. (a) Posterior–anterior chest plain flm. (b) Bra wiring seen in right mainstem

bronchus and bronchus intermedius. (c) Bra wiring visualized after bronchoscopic removal