Teaching Case

An 47 years unconscious patient was admitted to the emergency department after suffering from blunt trauma in a car crash.

A 47-year-old unconscious patient was referred to the hospitals emergency department after being involved in a high-speed car crash. X-ray of the pelvis showed a pelvic fracture. Chest X-ray performed in the emergency room showed a lung contusion and multiple rib fractures on the right side. No mediastinal pathology was seen. CT of the neurocranium revealed a small subarachnoidal hemorrhage. Transesophageal echocardiography showed an semicircular intramural hematoma of the left aortic wall at the origin of the left subclavian artery. Multislice helical CT (collimation 4 x 2.5 mm; pitch 1.25) confirmed the lung contusion on the right side and the rib fractures. In addition the semicircular intramural hematoma in the left lateral aortic wall at the origin of the left subclavian artery was visible. Sagittal and coronal multiplanar reformations demonstrated the band-like extension of the hematoma along the left lateral aortic wall of the aortic arch in caudal direction and along the proximal subclavian artery in cranial direction. To prevent further dissection an aortic stent graft was implanted 2 days after initial diagnosis of the intramural hematoma.

Traumatic aortic injury is a devastating and potentially lethal condition that should be diagnosed and treated immediately. Both CT as well as transesophageal echocardiography (TEE) have high sensitivity and specificity in diagnosis of traumatic aortic dissection. TEE shows even better results than angiography, which misses most minor (but potentially lethal) vessel wall injury. TEE has a sensitivity of 97% and a specificity of 100%, whereas angiography has a sensitivity of 83% and a specificity of 100% (1). Angiography fails to demonstrate minor changes like intramural hematoma and limited intimal flaps (1). CT-Angiography with single channel CT was reported to reach a sensitivity of 100% (3), and having a negative predictive value of 100% (2,3). However, gold standard for CT evaluation was angiography (1,3) with its known difficulties in detection of minor injury. Furthermore, all CT studies were performed prior to introduction of multislice helical CT into the clinical routine. Multiplanar reformations based on isotropic data sets are a powerful tool for diagnosis of even minor vessel injuries. Studies comparing the highly sensitive transesophageal echocardiography with multislice helical CT are still missing. Multislice helical CT may have good chances to reach the same sensitivity and specificity as TEE for the detection of even minor injuries of the thoracic aorta. In addition, multislice helical CT is providing additional information about pulmonary, mediastinal and upper abdominal injury. In the current case traumatic intramural hematoma in typical location was diagnosed by TEE and later seen in multislice CT. Clinical value of detection of minor aortic injury is still under investigation. Vilacosta et al. (4) could demonstrate that traumatic intramural hematoma resolved sponaneously in 3 of 6 patients. The other 3 patients died from multiorgan system failure and not from aortic rupture or dissection. A suitable therapeutic approach has to be established yet. In this case, the patient was treated by implantation of a aortic stent graft.