Reevaluation of diagnostic procedures for transmediastinal gunshot wounds.

BACKGROUND: Little controversy surrounds the treatment of hemodynamically unstable patients with transmediastinal gunshot wounds (TMGSWs). These patients generally have cardiac or major vascular injuries and require immediate operation. In hemodynamically stable patients, debate surrounds the extent and order of the diagnostic evaluation. These patients can be uninjured, or can have occult vascular, esophageal, or tracheobronchial injuries. Evaluation has traditionally often included angiography, bronchoscopy, esophagoscopy, esophagography, and pericardial evaluation (i.e., pericardial window) for all hemodynamically stable patients with TMGSWs. Expansion of the use of computed tomographic (CT) scanning in penetrating injury led to a modification of our protocol. Currently, our TMGSW evaluation algorithm for stable patients consists of chest radiograph, focused abdominal sonography for trauma, and contrast-enhanced helical CT scan of the chest with directed further evaluation. The purpose of this study is to evaluate the efficiency of contrast-enhanced helical CT scan for evaluating potential mediastinal injuries and to determine whether patients can be simply observed or require further investigational studies.

METHODS: Medical records of hemodynamically stable patients admitted with TMGSWs over a 2-year period were reviewed for demographics, mechanism of injury, method of evaluation, operative interventions, injuries, length of stay, and complications. CT scans were considered positive if they contained a mediastinal hematoma or pneumomediastinum, or demonstrated proximity of the missile track to major mediastinal structures.

RESULTS: Twenty-two stable patients were studied. CT scans were positive in seven patients. Directed further diagnostic evaluation in those seven patients revealed two patients who required operative intervention. Sixty-eight percent of patients had negative CT scans and were observed in a monitored setting without further evaluation. There were no missed injuries. The hospital charges generated with the CT scan-based protocol are significantly less than with the standard evaluation.

CONCLUSION: Contrast-enhanced helical CT scanning is a safe, efficient, and cost-effective diagnostic tool for evaluating hemodynamically stable patients with mediastinal gunshot wounds. Positive CT scan results direct the further evaluation of potentially injured structures. Patients with negative results can safely be observed in a monitored setting without further evaluation.