Angioedema Turned Aortic Dissection

Introduction: Angiotensin-converting enzyme inhibitor (ACE-I)-induced angioedema accounts for many emergency department visits. Clinicians may anchor on this diagnosis when patients present for facial swelling. However, facial swelling can have many causes ranging from an allergic reaction to superior vena cava syndrome (SVCS). Case Description: A 61-year old African-American male presented with facial swelling. He reported a history of hypertension and was prescribed lisinopril. Suspicion for ACE-I-associated angioedema was high; the initial plan was to stop that medication and monitor the patient to ensure that his swelling did not worsen. However, the patient revealed he also had chest pain. Tests were ordered to assess for acute coronary syndrome. Most were unremarkable, but the chest radiograph showed a widened mediastinum. A bedside ultrasound showed a large ascending aortic aneurysm with an associated proximal aortic dissection; a dissection flap was clearly visualized. After consulting with cardiothoracic surgery, a CT angiogram of the chest was obtained which showed a 7.7 cm dissecting aneurysm involving the ascending aorta and proximal aortic arch. The radiologist also noted there was marked compression of the superior vena cava due to the large aneurysm of the ascending aorta. The patient was taken emergently to the operating room where a 6.5-hour complex operation ensued. Although the patient was transferred to recovery in stable condition, multiple complications, including worsening SVCS, prolonged his intensive care unit stay. Life support was ultimately terminated after a five-week hospital stay. Discussion: Superior vena cava syndrome is most commonly caused by advanced stages of lung cancer. Today, only 5% to 22% of all cases of SVCS in developed countries are not caused by cancer, and most of these are caused by thrombosis due to central venous catheters and pacemakers. Thoracic aortic aneurysm, which itself is reported to have a prevalence of 0.16%, is a rare cause of SVCS, with only a few previously documented cases. Furthermore, patients may remain asymptomatic for a long time and the clinical signs of SVCS are often nonspecific. Especially in nonmalignant cases of SVCS, all of these factors can misdirect the correct diagnosis, as it did for us. Thus, it is important to keep the differential diagnosis for any symptom broad, even when the diagnosis seems obvious.