There are few comprehensive reports of neck trauma. Injury to major organs, such as the common carotid artery, internal jugular vein, pharynx, trachea, and esophagus, results in a fatal outcome. There is not a standard treatment protocol for neck stab wounds . According to a report by Demetriades, esophageal injury was observed in 0.9% of penetrating neck injuries and commonly caused by gunshot wounds (0.5%), followed by stab wounds (0.3%) . In Japan, gunshot wounds are uncommon, therefore the majority of neck injuries are stab wounds caused by knives, and most are suicide attempts . It has been reported that 90% of neck stab wounds involve the shallow cervical region, which is shallower than the vast lateral, sternocleidomastoid, and anterior cervical muscle groups, and that deep neck injuries are rare . Previous reports suggest that esophageal injuries, especially those involving the thoracic esophagus rather than the cervical esophagus, have a high mortality rate [1, 7]. Therefore, esophageal injuries should not be overlooked.
Zone classification has long been used to diagnose neck injuries [8, 9]. They are divided into three zones, from the clavicle to the base of the skull. In Zone II (from the level of the cricoid cartilage to the mandibular angle), which accounts for the majority of neck injuries, there are many vital organs including the common carotid artery, internal jugular vein, trachea, and esophagus. It has been reported that more than half of patients with significant cervical vessel injuries die .
Esophageal injury may cause a sore throat, minor subcutaneous emphysema of the neck, and hematemesis. However, these are common symptoms of neck trauma and are not specific to esophageal injuries . In particular, perforation of the thoracic esophagus rarely presents with specific symptoms, and diagnosis tends to be delayed in the upper and middle thoracic esophagus compared to the cervical and lower thoracic esophagus . Although conservative treatment may be an option for esophageal perforation depending on the condition, the longer the time since the onset of the disease, the more likely the perforation is to be necrotic and fragile due to high contamination. These patients require surgical treatment . In idiopathic rupture of the esophagus, Cameron et al. reported that conservative treatment (such as thoracic drainage and intermittent continuous suctioning of the esophagus) is possible when all the following conditions are met: (i) rupture is confined to the mediastinum; (ii) drainage into the esophagus through the rupture site; (iii) symptoms are mild, and (iv) there is no severe infection .
On the other hand, Zenga et al. reported that surgical treatment is necessary when any of the following conditions are met: (i) oral intake from injury to diagnosis; (ii) passage of more than 24 h from injury to diagnosis, and (iii) deterioration of general condition . In addition, the longer the time since the onset of the injury, the more likely it is that suture failure will occur after closure, and Anderson states that 24 h after onset is the safe limit for direct suture closure without suture failure . Considering these facts, we assumed a high risk of suture failure in upper mid-thoracic esophageal injuries. Our case also fulfilled Zenga's requirements (i) and (ii), and surgical treatment was appropriate. We attempted direct suture closure because of mild contamination, lack of severe infection, and relatively small perforation diameter, and performed gastrostomy in anticipation of suture failure. Unfortunately, postoperative suture failure occurred, but the patient could recover by using an external fistula with a drain and nutritional therapy using a gastrostomy. There are some reports of delayed diagnosis and difficult suture closure, esophagectomy, cervical esophageal fistula and gastrostomy, and two-stage reconstruction may be performed [3, 15].
While angiography, CT, esophagography, and endoscopy are recommended to diagnose esophageal injury, evaluation is often difficult . The injury mechanism also aids in the diagnosis of an injured organ. In the case of self-injury, the blade tip is thought to enter the wound level with or more cranial to the skin wound. Conversely, when another person swings the blade, the blade tip is likely to enter caudal to the skin wound. Therefore, it is necessary to assume the possibility of organ damage caudal to the cutaneous wound when harming others. In this case, there was an esophageal injury caudal to the neck wound. Some studies argue against using the zone classification approach, stating that there is no correlation between the height of the trauma site and the internal injury site .
In our case, we could diagnose esophageal injury at a relatively early stage, and the patient did not develop serious complications such as mediastinitis, pyothorax, or tracheoesophageal fistula. Considering that it was a neck stab wound caused by the attack, the weapon was unknown, and the CT findings showed a right upper lobe pulmonary contusion, we potentially could have diagnosed the esophageal injury earlier. The possibility of thoracic esophageal injury should always be considered when dealing with neck stab wounds caused by attackers.