There is general agreement that patients who are hemodynamically unstable or have obvious aerodigestive injury require immediate surgical intervention. In those who are stable, the diagnostic approach is determined by the location of the wound. Nonoperative studies are used to identify injuries in zones I and III. Vascular control is often difficult to obtain in these zones. Zone I injuries require a thoracic surgical approach to gain proximal vascular control, important for arterial injuries. Both proximal and distal vascular control is easily obtained in zone II. For zone III, arterial injury proximal control is actually gained in zone II. More distal injury presents a difficult problem in zone III. Disarticulation of the mandible may be required for adequate exposure. Given these technical difficulties, routine exploration of zones I and III is not indicated. Both of these zones should be studied with angiography, as physical examination is not always reliable in identifying vascular injuries. 8 Zone I also requires diagnostic evaluation of the esophagus, as early injuries are often asymptomatic. The operative difficulties encountered in zones I and III are usually not a problem in zone II injuries.
Controversy surrounds the management of stable patients with zone II injuries. Literature supports both mandatory exploration of all injuries that penetrate the platysma as well as selective operation based on diagnostic studies. Mandatory exploration was popularized during World War II, as this intervention lead to markedly reduced morbidity and mortality. Advocates of mandatory exploration describe low complication rates following negative operations, as well as significant morbidity associated with missed injuries. There is also concern that diagnostic modalities that are used to detect aerodigestive injuries are inaccurate. Opponents of mandatory exploration cite its high negative exploration rate. In addition, an injury may be missed during surgical exploration. Alternatively, an injury may be discovered that is difficult to control surgically, such as a vertebral artery injury. Surgical exploration alone is often technically difficult with these injuries, particularly if the vascular anatomy and possible vertebral artery anomalies are not first identified by angiogram. Angiography helps clarify management. Complete occlusion of a vertebral artery in an asymptomatic patient with a normal contralateral vertebral artery and no evidence of a distal AV fistula is usually managed conservatively. The patient with active arterial bleeding, AV fistula, or pseudoaneurysm of the vertebral artery is preferably treated by percutaneous transcatheter embolization of the proximal and distal vertebral artery. On occasion, angiographic procedures are used during surgery to aid in obtaining vascular control. Obviously, if angiography is unavailable or unsuccessful, surgical exploration and repair is performed. 9 Selective management results in minimal nontherapeutic operations and spares the patient a surgical scar. No definitive evidence exists to establish one treatment paradigm as being more cost effective than the other.
Further controversy in the management of zone II injuries focuses on the diagnostic role of physical examination. Some advocate observation alone in asymptomatic patients with zone II injuries.1 U Studies supporting this management have been largely retrospective or had small sample sizes. Missed arterial and esophageal injuries have been demonstrated in asymptomatic patients.58 Clinical signs and symptoms have low sensitivity, specificity, and predictive value. -s,.1.2 In addition, multiple-injury patients may have associated injuries that make physical examination of the neck less reliable. Selective exploration based on the results of diagnostic studies should be done. This will decrease the rate of negative explorations, yet avoid missing injuries. Evaluation of zone II injuries should routinely include vascular and esophageal evaluation.
Angiography is currently the gold standard for evaluating vascular injury and can also be therapeutic. Duplex sonography is being used with increasing frequency. It is noninvasive, but it is operator-dependent and its sensitivity at detecting small lesions or intimal flaps is not yet established.
Esophageal evaluation must be performed in all patients because esophageal injuries with injuries in zones I and II are initially notoriously asymptomatic. Delayed treatment of esophageal perforations will result in neck space infections and mediastinitis. Ideally, evaluation should include both an esophagram and esophagoscopy. Using this combination of studies, the sensitivity of detecting injury is increased to nearly 100 percent. 13 Flexible, rather than rigid, esophagoscopy is the current procedure of choice.
Laryngotracheal injuries are of concern in zones I and II. Significant laryngotracheal injuries are rarely occult. Diagnosis is usually easy due to the anterior and superficial position of the trachea. Air-bubbling through the wound, dyspnea, stridor, hemoptysis, and subcutaneous emphysema are the most common signs and symptoms. Although optimal management is controversial, diagnostic evaluation with laryngoscopy and bronchoscopy is generally reserved for those who are symptomatic.
In summary, stable patients with zone I injuries should undergo angiography and esophagram, and/or esophagoscopy. Those with zone III injuries should undergo angiography. Patients with zone II injuries can undergo mandatory exploration or be evaluated with angiography and esophagram, and/or esophagoscopy. Patients with symptoms suggestive of laryngotracheal injury require laryngoscopy and bronchoscopy ( Fig. 2.50.-.4). Despite the presence of a single wound, multiple zones may be involved. This happens most often when the injury is caused by a gunshot. Diagnostic evaluation should be liberal and account for all structures that may have been in the pathway of a trajectory.
been in the pathway of a trajectory.
It is important to recognize that to a large degree diagnostic evaluation is institution- and personnel-dependent. Available resources often determine the optimal diagnostic regimen.
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