1. Deep cervical infection or abscess Foreign body penetrating the lateral wall of the cervical esophagus can lead to peresophageal infection and abscess formation, located in the gap between the thyroid gland and the esophagus. If it penetrates the posterior wall of the esophagus, a retropharyngeal abscess will form, compressing the larynx or trachea. All these inflammations can spread to the mediastinum and cause mediastinal infection or abscess. 2. Mediastinal infection A large perforation of the thoracic esophagus can immediately lead to a mediastinal emphysema, with upward diffusion of gas to a subcutaneous cervical emphysema and subsequent formation of a mediastinal infection or abscess. There are also cases of mediastinal infection caused by esophageal tearing and perforation due to pushing and pulling of foreign bodies during foreign body removal. 3, bronchopulmonary and thoracic infection complications Direct penetration or compression of the esophagus by the foreign body can cause tracheal or bronchial fistula. Complications such as pulmonary inflammation, pulmonary atelectasis, and pulmonary abscess occur when the contents of the esophagus are inhaled into the whistle through the fistula. Untreated mediastinal infections can involve the pleura or foreign bodies directly penetrate the mediastinal pleura to contaminate the chest cavity and form a pustule. 4.Injury to large blood vessels causing esophageal-arterial fistula The middle esophagus is anatomically adjacent to the aortic arch and the left bronchus to form a physiological stenosis, which makes it easy for foreign bodies to stay. If sharp bone fragments such as fish, crab, shell, poultry, etc. are pierced into the wall of this section of the esophagus, the swallowing peristalsis, large blood vessel pulsation, strong swallowing of food, vomiting and coughing can prompt the foreign body to penetrate the wall of the esophagus, causing injury or penetrating into the aorta and forming an aortic fistula after infection. If the fistula occurs after the process of esophageal necrosis and infection due to compression of the esophagus, the inflammatory reaction is chronic, the fibrous tissue proliferation is more, and the fistula hole is small, which can provide favorable conditions for surgery. If the inflammatory reaction is heavy, repair is more difficult. The clinical manifestations of esophageal foreign body injury to the aorta all have varying degrees of acute hematemesis. The vomiting of blood is usually small at the beginning and is called signal vomiting. The bleeding may be suspended due to contraction of the aortic wall orifice, a drop in blood pressure after bleeding, and blockage of the fistula by a blood clot. Fatal hemorrhage can occur again later due to infection or clot migration. The time from signal bleeding to fatal bleeding has been reported to vary from 2h to 3 days, with an average of 1 day. Comprehensive domestic reports of more than 80 cases of esophageal foreign body complicated by aortoesophageal fistula only 4 cases were cured. Other vascular injuries include common carotid artery, subclavian artery, jugular vein, and innominate vein. After perforation of the jugular vein, a pulsatile or conductive pulsatile mass may appear on the side of the neck, and local puncture may draw fresh blood, which should be treated surgically in a timely manner. Patients who develop esophageal aortic fistula should be closely monitored and surgical treatment should be performed in a prepared condition.