The anterior neck is divided into three zones defined by horizontal planes. Which of the following statement(s) is/are true concerning penetrating injuries to the anterior neck?

a. Penetrating injuries to Zone I carry the highest mortality

c. Exposure of Zone III for detection of injuries to the distal carotid artery and pharynx can be quite difficult

d. All hemodynamically stable patients with penetrating injuries to Zone I should have angiography

The anterior neck is divided into three zones defined by horizontal planes. Zone I represents the base of the neck and it invariably extends from the sternal notch to the top of the clavicles or the cricoid cartilage. Injuries here carry the highest mortality because of the risk of major vascular and intrathoracic injury. Zone II is the mid-body and largest portion of the neck. It extends from the top of Zone I to the angle of the mandible. Zone II injuries are most common but carry a lower mortality rate than either Zone I or Zone III injuries, since the injury is generally apparent and exposure of the vital structures is readily accomplished. Zone III is that part of the neck above the angle of the mandible. The risk of injury to the distal carotid artery, salivary glands and pharynx is greatest in this zone. Exposure in this region can be particularly difficult.

Most surgical groups advocate exploration in the majority of penetrating neck wounds that penetrate the platysma in Zone II and in all patients with clinical signs of tracheal, esophageal, or major vascular injury. Preoperative angiography is generally not required for Zone II injuries because of the relative ease of exposure and control of critical vascular structures. Zone I and III penetrating injuries are selectively managed based on clinical presentation and the result of diagnostic studies. Hemodynamically unstable patients are immediately explored with operative incision based on the most likely source of vascular injury. Zone I injuries are essentially managed similar to mediastinal traversing wounds. Angiography is performed in all hemodynamically stable patients with penetrating wounds to Zone I to identify potential injuries to the thoracic outlet vessels or to plan better operative approach. Angiography is also performed for Zone III injuries, because of the possible inaccessibility of the internal carotid artery lesions or to demonstrate a need for systemic anticoagulation. Furthermore, most of the vascular lesions identified at the base of the skull are best managed by interventional angiography techniques.