Mega aorta syndrome: a case of thoracic and abdominal aortic aneurysm

An 83-year-old woman presented to the emergency department (ED) via emergency medical services with the chief complaint of "strokelike symptoms." Physical examination revealed altered mental status, tachycardia, hypotension, and a large nonpulsatile periumbilical mass. Bedside ultrasound revealed a 9-cm abdominal aortic aneurysm with absent central flow. Computed tomography scan demonstrated diffuse thoracic and abdominal aortic dilation with rupture into the mediastinum along with left hemothorax. Repeat beside ultrasound demonstrated abdominal aortic aneurysm rupture not seen on the computed tomography scan. Despite aggressive resuscitation, the patient developed bradycardia, which devolved into pulseless electric activity cardiac arrest. She was unable to be resuscitated. The patient's diffuse aneurysmal dilation places her into the small category of patients with a disease entity known as mega aorta syndrome (MAS). Mega aorta syndrome is defined as aneurysmal dilation of the aorta to greater than 6 cm in diameter. Although not in our case, most cases of MAS are symptomatic before catastrophic presentation. The disease progression for these patients is slow and occurs over years. When this disease is recognized early, a surgery known as the elephant trunk procedure can be performed. This operation replaces the entire aorta in multiple stages. This gives the emergency physician a critical role in the diagnosis and outcome of these patients because they may come through the ED for an unrelated complaint early in the disease process. This case report illustrates an advanced case of MAS.