Leaking Saccular Aortic Arch Aneurysm
A 71-year-old man complained of central chest pain radiating to his back and neck and both arms. Investigations for ischemic heart disease were negative. Chest x-ray showed a soft tissue density in the aortopulmonary area. CT scan revealed a saccular aneurysm arising from the inferolateral aspect of the mid-transverse arch of the aorta, measuring a maximum diameter of 7 cm (Figure 1). The presence of fluid in the left pleural space signified a leaking aortic aneurysm. Aggressive management of blood pressure was undertaken, and the patient was promptly transferred to surgery.
Left lateral thoracotomy through the fourth intercostal space was performed. Blood (1.5 L) was aspirated from the pleural space. An impressive saccular aneurysm arising from the undersurface of the aortic arch, displacing the surrounding structures, was noted. The left phrenic nerve was paralyzed, raising the left hemidiaphragm. The left recurrent laryngeal nerve was displaced dorsally by mass effect of the aneurysm. The apex of the aneurysm showed areas of wall weakness, which facilitated the leakage of blood (Figure 2, arrow). Cardiopulmonary bypass was established by cannulating the left atrial appendage for drainage and descending thoracic aorta for arterial return. With circulatory arrest, the aneurysm was carefully dissected and excised. Inspection of the aneurysm from inside showed areas of porosity and defects in the vessel wall thickness, which permitted blood seepage. After excision, the defect in the aortic wall measuring 3.5 cm × 3.5 cm was repaired with bovine pericardium. The patient made a complete recovery without evidence of recurrent nerve injury. It is rare to see such incipient and impending rupture of an aortic arch saccular aneurysm. These images reinforce the need for aggressive preoperative management of arterial pressure and prompt surgical intervention.
The authors thank the CT department of St. Richards Hospital, Chichester, UK, for allowing the use of Figure 1.