Pulmonary alveolar hemorrhage from a pulmonary artery false aneurysm after Swan-Ganz catheterization in a thoracic aortic aneurysm patient: a case report.

Pulmonary artery (PA) rupture caused by a PA Swan-Ganz catheter is a rare complication but remains fatal in almost 50% of cases. False aneurysm of the PA is a rare presentation of PA rupture and should be considered as a possible diagnosis in a patient with a new lung mass after PA catheterization. We present a case of sudden-onset pulmonary alveolar hemorrhage during cardiovascular surgery due to a traumatic PA false aneurysm. The Swan-Ganz catheter might have been displaced by the thoracic aortic aneurysm with displacement of the catheter causing the false aneurysm and bleeding.