Pulmonary artery sheath hematoma.

Dissection of the ascending aorta (AA) represents a life-threatening condition typically treated by emergent surgical repair. A rare, potential complication of AA dissection is pulmonary artery (PA) sheath hematoma. Due to the presence of a common adventitial layer between the proximal AA and the PA, dissection can propagate between both vessels, potentially compromising the PA lumen. The resultant acute narrowing of the PA lumen may abruptly increase right ventricular (RV) afterload. Recognition of PA sheath hematoma is important; when seen on echocardiography it is suggestive of AA dissection and has the potential to result in RV hypertension and dysfunction if significant PA compression occurs.