Snapshot A 32-year-old man with eunuchoid proportions and arachnodactyly presents to the emergency department with severe substernal chest pain that radiates to the back. He says that the pain occurred acutely and denies any recent trauma. Medical history is significant for Marfan syndrome. On physical exam, there are unequal blood pressures in the upper extremity. A chest radiograph demonstrates a widened mediastinum. A CT angiography demonstrates a Stanford A type aortic dissection. Summary Aortic dissection is a condition that results from a tear in the innermost layer of the aorta leading to a hematoma and separation of layers of the aortic wall. Patients with hypertension and advanced age are more at risk for dissection. These patients typically present with abrupt onset of severe, tearing chest pain. Diagnosis is made with CT angiography or transoesophageal echocardiogram. Chest X-ray is often acquired first, which may show a widening of the mediastinum. Treatment depends on the type of dissection. Regardless though, medical therapy is concurrently initiated with IV beta-blockers, IV fluids for hypotension, and surgical therapy indicated for type A dissections. Epidemiology Incidence common > 1/100,000 annual incidence Demographics 3:1 male to female ratio typically affects adults between the ages of 40-70 risk factors include hypertension atherosclerosis aortic aneurysm Turner syndrome Marfan syndrome Ehlers-Danos syndrome Etiology Pathophysiology mechanism an intimal tear of the aorta causes an intramural aortic hemorrhage that separates the intima from the media login to view 1 more bullet there are two types of aortic dissection login to view 4 more bullets cell biology dissection involves fragility of the media layer of the aorta login to view 1 more bullet Associated conditions Hypertension (most common) Connective tissue disease Iatrogenic (e.g., coronary catheterization) Trauma bicuspid aortic valves lead to backflow which can enlarge the aorta and weaken the wall stability e.g., Turner syndrome Marfan syndrome results in cystic medial necrosis in the tissue of the aorta Anatomy The aorta has three distinct wall layers Adventitia outermost layer login to view 1 more bullet Media middle layer login to view 3 more bullets Intima innermost layer login to view 2 more bullets Presentation History sudden onset of severe, 'tearing' chest pain can be painless in some patients, commonly those with Marfan syndrome Symptoms acute chest or back pain (most common) classically anterior chest pain that radiates to the back between the scapulae Physical exam inspection unequal blood pressures in the arms weak or absent pulses auscultation findings login to view 2 more bullets Imaging Radiographs indication to rule out other causes of chest pain (e.g., pneumothorax) recommended views chest x-ray with anteroposterior (AP) view finding widened mediastinum deviation of the trachea to the right deviation of the esophagus CT angiography of the chest indication most accurate imaging test for aortic dissection MR angiography of the chest can be used in stable patients with iodine contrast allergies considered gold standard for diagnosis findings intimal dissection flap dilation of the aorta and hematoma double lumen contrast leak Transesophageal echocardiography indications can be used if kidney injury is present or patient is allergic to contrast findings thrombosis in the new lumen pericardial effusion Differential Aortic embolism findings found with aortic embolism but not with aortic dissection occlusion at aortic bifurcation on CT angiography limb pain cyanosis, pulselessness, and pallor Myocardial infarction (MI) findings found with myocardial infarction but not with aortic dissection electrocardiogram findings (e.g., ST-segment elevation) increased cardiac biomarkers (i.e. troponin) Treatment Medical Pharmacological IV ß-blockers and anti-hypertensives login to view 3 more bullets IV fluids and vasopressors login to view 2 more bullets Surgical Aortic dissection repair indication login to view 2 more bullets outcomes login to view 1 more bullet Techniques Aortic dissection repair approach open heart surgery with a cardiothoracic surgeon under general anesthesia technique sternotomy and aortic flap creation complications endoleak infection bleeding stroke lower limb ischemia Complications End-organ damage secondary to poor perfusion acute renal failure acute abdomen mesenteric ischemia ischemic colitis paraplegia or weakness of lower extremities aortoiliac occlusive disease aortic regurgitation Myocardial infarction from coronary artery occlusion incidence estimated to be 1% to 5% risk factors coronary artery disease hypertension treatment percutaneous coronary intervention dual antiplatelet therapy anticoagulation Stroke incidence between 3-32% of aptients risk factors patients with concomitant chest pain, shock, and hypotension. treatment anti-thrombolytics or tPA mechanical thrombectomy Cardiac tamponade incidence between 8-31% of patients risk factors surgical repair for type A aortic dissection treatment pericardiocentesis pericardectomy Prognosis Overall poor prognosis 20-30% mortality rate for patients prognosis dependent on type of dissection Stanford type A login to view 2 more bullets Stanford type B login to view 2 more bullets