Delayed presentation of a penetrating neck injury: diagnostic and management difficulties with retained organic material

Abstract

Penetrating neck wounds complicate approximately 10% of all trauma presentations.1 While they are most commonly associated with violent acts, they are also encountered in road traffic collisions and other accidents. The adverse relationship between alcohol and trauma is well-documented.2 The mechanism of penetration is important in determining the extent of damage and treatment options. Ballistic missiles trauma can cause extensive damage which is highly correlated with the velocity. Stab wounds are relatively low velocity, but can still lead to serious injury. Management in both instances should initially follow ATLS guidelines, with careful attention to airway and cervical spine protection. As with any tissues, penetration and retention of foreign material carries an increased risk of infection. The neck has a dense concentration of neurovascular and aerodigestive structures passing through it, which can be damaged by injuries which penetrate the platysma muscle. It is useful to divide the neck horizontally into three zones. Zone I extends between the clavicles and the cricoid cartilage; it carries the highest mortality because of vascular injury and high-risk surgical exploration.3 Zone II is superior to Zone I and extends as far as the angle of the mandible. Zone III is the area between the angle of the mandible and the base of the skull. Zone II injuries are the most common followed by Zone 1 and finally Zone III.4 Injuries may occur in more than one zone. Inevitably vascular injury is the most frequent complication of penetrating neck trauma, occurring in one-quarter of all cases, and carrying a mortality of nearly 50%. Trauma to the trachea occurs in one-tenth of cases, and mortality in these cases approaches 20%.5 Other structures at risk of damage include the oesophagus, which can cause leakage of digestive enzymes and bacteria into surrounding tissues; and the cranial nerves. Extensive penetration may result in oropharyngeal trauma. Currently it is thought that penetrating neck injuries carry a 3–6% mortality rate.6 The mortality rate for Zone II stable injuries is generally perceived to be lower than this, although there are no large studies to back this up. In the postwar era it was shown that the mortality associated with penetrating neck wounds dropped from around 35% to 6% when immediate surgical exploration was performed.7 Now, with advanced imaging techniques and increasing experience, selected stable patients with no hard findings of injury can be managed by thorough examination and, if unremarkable, a period of observation rather than immediate surgical exploration. A review by Tisherman et al.8 on penetrating Zone II neck trauma found that selective operative management and mandatory exploration of penetrating injuries to Zone II had similar diagnostic accuracy, therefore selective management is recommended to avoid unnecessary operations. Stable patients without clear signs of vascular and visceral injuries can avoid mandatory surgery. Instead high-resolution CT angiography was recommended to give detail about vascular, tracheal and oesphageal injuries. CT without angiography can be used to rule out significant vascular injury if the trajectory is shown to be away from vascular structures. There are no studies on the management of retained organic material in stable Zone II neck injuries or data on the management of cases that have a delayed presentation. In general, however, it is recommended that patients with retained wood or vegetative material and pain have foreign body removal.9 Retained material such as thorns can lead to granulomatous formation. In one autopsy study of patients with tendon injuries organic matter was associated with purulent tendonitis, necrosis, foreign body granuloma, fibrosis and peritendonitis and calcification.10 Penetrating ingested foreign bodies can remain quiescent for years but can cause late mortality from diffuse and local suppurative processes especially if leading to vascular injuries.11 This case describes the delayed diagnosis of a penetrating neck injury by a piece of bamboo which missed all the major structures of the neck, and considers the consequences of retained organic foreign bodies in the soft tissues.