2 collected at the Children’s Hospital Gutierrez in Buenos Aires over a ﬁve-year period. 2.2. Statistical Analysis. Details on injuries were collected, and a descriptive statistical analysis regarding (i) children demographic characteristics (age and sex), (ii) features of the object (dimensions and consistency), (iii) circumstances of the injury, (iv) clinical presentation (v) FB locations, and (vi) outcomes (complications and removal’s strategy) was provided. Moreover, a search on PubMed database has been performed in order to retrieve other case series describing FB in the esophagus, representative of diﬀerent cultural and geographical backgrounds. In 2009, Gregori et al. collected data on FB injuries in the aerodigestive tract in paediatric patients from 19 European Hospitals, recording 2103 injuries occurring in the years 2000–2002 [7]. In 2007, Lin et al. performed a study on foreign body ingestion over a 5- year period in children living in Taiwan, reviewing medical records of children who were referred to the paediatric emergency department of a single tertiary referral centre between December 2001 and May 2006 [8]. A total of 74 patients underwent an endoscopic procedure because of suspected foreign body ingestion, and in 38 cases the object was located in the esophagus. In 2006, Little et al. conducted a retrospective analysis of the medical records of children who were referred to Children’s Mercy Hos- pital, Kansas City, Missouri, with a foreign body lodged in the esophagus [9]. Over the 16-year period, from January 1988 to October 2004, 555 children had that discharging diagnosis. In 2003, Van As et al. analyzed injuries due to FB ingestion among the 88822 patient streated in their trauma unit from 1991 to 2000. Among those injuries, 753 were FBs wedged in the esophagus [10]. From all revised papers, data regarding children age and sex, FB type, location, adult supervision, most frequent symptom and complication, and delay at diagnosis, were drawn and compared with our experience. 3. Results During the ﬁve-year study period, 320 cases of foreign body ingestion with esophageal location were observed. Children’s mean age was 4.58 years (SD 1.42), ranging from 2 to 9 years old. In the majority of cases (304 patients), injuries happened while the child was playing; in 273 cases (85.3%) adults were present. In Table 1, all the retrieved foreign bodies are described. Children most frequently ingested coins (268 cases, 83.8%), that eventually remained stuck in the esophageal portion; among the recovered items, other round objects like buttons (11 cases, 3.44%) and plastic pieces (15 pieces, 4.69%) were subsequent for frequency. Most children showed vom- iting (92, 28.7%). In 75 cases (23.4%), odynophagia was encountered. Lower frequencies were seen for sialorrhea (38 cases, 11.86%), ptyalism (31 cases, 9.69%), and dysphagia (28 cases, 8.75%). However, 47 cases (14.69%) showed no symptoms. Foreign Bodies Coins Bones Plastic pieces Button Metal Tags Pin Ring Toy Total 268 15 15 11 3 3 2 2 1 320 International Journal of Pediatrics Table 1: Description of retrieved foreign bodies. In 145 cases (45.31%), diagnosis was formulated within 3 hours after the injury and in 146 cases (45,6%) with a delay greater than 3 hours but not longer than 24 hours; only in 29 cases (9.06%), the FB was detected after more than 24 hours. The FBs were located in the majority in the middle esophagus (269 cases, 84.1%). Removal was performed in all cases, in 34 by esophageal- forceps and in 286 cases using Magill hypopharyngeal forceps. General anaesthesia was administered in all cases. There was just one case where complications were observed (0.31%), presenting esophageal perforation. In Table 2, a comparison between characteristics of the present case series and characteristics of previously published case series is provided. Some information (such as the adult presence) is frequently underreported, and more generally, information is not univocally categorized, impairing the possibility to perform any comparative eﬀort. 4. Discussion FB injuries in the upper digestive tract continue to be a com- mon health problem in paediatric patients. In the present study, the majority of cases involved children between 2 and 9 years of age, showing similarities with the results of the ESFBIs study and with Lin’s study [8]. Less often, older children have risky behaviours, and this decrease of risk is as well ensured by the augmented size of the esophagus. In scientiﬁc literature, the most frequent foreign bodies result in ﬁsh bones, metal objects such as batteries and coins, and broken tooth fragments [11, 12]. Tissue response to a foreign body varies according to the composition of the FB and to any associated bacterial overinfection. Organic fragments cause a greater acute inﬂammation in comparison to pieces of metal, plastic, or bone. The relative inert nature of plastic materials allows the relatively quick response of patient upon removal of the foreign body, implying a milder tissue inﬂammation. Several authors have enlightened some diﬀerences between Asian and Western paediatric injuries due to foreign body ingestion, claiming that the speciﬁc type, food inﬂuences age distribution and nature of esophageal foreign body [2, 13]. In our study of coins were by far the most frequent foreign bodies ingested, followed by plastic