Diagnosis of traumatic mediastinal hematoma with transesophageal echocardiography.
In patients with blunt chest trauma, early diagnosis of mediastinal hematoma is important, because it could be associated with thoracic vessel injury. Mediastinal hematoma is generally evoked because of a widened mediastinum on chest radiograph, but radiologic diagnosis may lead to excessive angiography being performed. Transesophageal echocardiography (TEE) provides accurate views of the mediastinum and can be rapidly performed at the bedside. Thus, we conducted a prospective study to define TEE signs of mediastinal hematoma. TEE was performed in 22 thoracic trauma patients (trauma group) and in 20 brain-dead patients without thoracic trauma (control group). The positive diagnosis of mediastinal hematoma was made using thoracic surgery or computed tomographic scan. The specificity of TEE was 75 percent and sensitivity was 100 percent. In the trauma group, there was only one false positive but angiography discovered a traumatic aneurysm of the proximal right subclavian artery. No false negative was noted. We described three different TEE signs of mediastinal hematoma: (1) an increased distance between the probe and the aortic wall; (2) a double contour of the aortic wall; and (3) visualization of the ultrasound signal between the aortic wall and the visceral pleura. The distance between the esophageal probe and the aortic wall was the most accurate sign because it could be easily obtained; the threshold value for this distance was 3 mm. TEE appears to be an accurate method to diagnose traumatic mediastinal hematoma.