Emergency Ultrasound Diagnosis of Type A Aortic Dissection and Apical Pleural Cap

A 70-year-old man with a medical history significant for hypertension, permanent pacemaker placement, and a remote repair of a type A aortic dissection presented to the emergency department with sudden onset of sharp anterior chest pain and hemoptysis. He was in no respiratory distress, but appeared markedly uncomfortable and had a cough productive of small quantities of bright red blood. His initial heart rate was 85 beats/min, his respiratory rate was 24 breaths/min, his oxygen saturation was 97% while breathing room air, and his blood pressure was 113/76 mm Hg.

After initial stabilization, a bedside cardiac ultrasound was performed by the emergency physician using a 5–1 MHz phased array transducer (Philips HD11XE, Andover, MA), which demonstrated a large aneurysm of his descending thoracic aorta, with a visible intimal flap (Figure 1 and Video Clip S1). Given the patient’s hemoptysis, a focused lung examination was then performed using a 5–2 MHz curvilinear array transducer (Philips, Andover, MA). This demonstrated a left anteroapical pleural fluid collection with internal echoes, consistent with hemorrhagic fluid (Video Clip S2). Chest radiography confirmed a widened mediastinum with a left-sided apical cap (Figure 2). The cardiothoracic surgery service was called to evaluate the patient, and computed tomography angiography of his thoracic aorta confirmed a large thoracic aortic aneurysm with a type A aortic dissection and an associated left-sided apical hemothorax (Figure 3). The patient was taken emergently to the operating room where these findings were confirmed. Although the aortic arch was successfully repaired, continued bleeding and extension of the dissection throughout the distal aorta led to intraoperative hemodynamic collapse, and the patient expired.

Figure 1.  Parasternal long-axis view of the heart demonstrates an intimal flap (asterisk) within an enlarged descending thoracic aorta (ao). The left ventricle (lv), left atrium (la), and right ventricle (rv) are labeled for reference.

Figure 2.  Portable upright anteroposterior chest radiograph demonstrates a widened mediastinum and opacification of the left hemithorax.

Figure 3.  Contrast computed tomography angiography demonstrates an aneurysmal aortic arch with an intimal flap. The true lumen of the aortic arch (a), false lumen (f), and intimal flap are visualized. A collection of apical pleural blood (p) is also seen.

Recurrence of type A aortic dissection occurs in up to 35% of patients with Marfan’s syndrome who undergo repair of the ascending aorta and/or aortic arch. In patients without Marfan’s syndrome, recurrence of type A aortic dissection has been reported in up to 12.5% of cases.¹