P001: INCIDENTAL FINDING OF LEFT ATRIAL THROMBUS DURING SURGICAL MANAGEMENT OF A MASSIVE PULMONARY EMBOLISM
Sarah A Dunn, MD, MPH, Nisha Dave, DO, John Sciarra, MD, Yilliam F Rodriguez-Blanco, MD, Oscar Aljure, MD; Jackson Memorial Hospital
Introduction: A patent foramen ovale (PFO) may serve as a conduit for passage of thrombi across the interatrial septum and put a patient presenting with a saddle pulmonary embolus at risk for paradoxical emboli. This is a rare diagnosis with no established treatment guidelines.
Case Presentation: This is a case of a 58-year old man with a past medical history of hypertension and paranoid schizophrenia that presented with complaints of increasing fatigue, inability to walk 200 meters, and dizziness with mild blurred vision. Arterial blood gas revealed mild hypocapnia and hypoxemia. CT angiogram revealed a saddle embolus in the main pulmonary artery with extensive clot burden affecting all lobes and right heart strain with reverse curvature of the septum. Subsequently, transthoracic echocardiogram displayed a severely dilated right ventricle (RV) with severely reduced systolic function. The interventricular septum was flattened and consistent with pressure and volume overload. A mobile thrombus was seen in the right atrium that measured 2.7 by 1.2 cm.
The patient underwent emergent pulmonary embolectomy for massive pulmonary embolus with hypoxemia and RV distention. Intraoperative transesophageal echocardiography revealed a massive thrombus in the right atrium extending to the superior vena cava. Incidentally we found a large thrombus in the left atrium. Operatively, the patient underwent sternotomy with cardiopulmonary bypass. Massive pulmonary emboli and clots were removed from both the left and right pulmonary artery.
After removal of the thrombus, transesophageal echocardiogram showed a PFO. An IVC filter was additionally placed at the end of the procedure. The patient progressed well with aggressive medical management and did not suffer any neurological consequences.
Discussion: A PFO is the most common congenital anomaly occurring in 25-35% of the population. Thrombus may travel from the right atrium to the left atrium and may affect cerebral or coronary circulations. When left atrial pressures are greater than right atrial pressures, there is a functional closure of the foramen ovale. Conditions that cause right atrial pressures to exceed left atrial pressures will lead to a right to left shunt. In this case, we saw an incidental mass in the left atrium which most likely was a thrombus that passed across the PFO. This demonstrated right to left shunting from increased right atrial pressures secondary to increased pulmonary pressures. This is a particularly rare case because of the incidental intraoperative finding of the PFO that placed this patient at increased risk due to possible paradoxical embolism. There are few cases reported of a saddle pulmonary embolism with thrombus that migrated across a PFO and as such, there are no formally established treatment guidelines. Surgical embolectomy, however, does have superior outcomes compared to medical treatment with anticoagulation or thrombolysis.
Grander W, Schachner T, et al: Patent Foramen Ovale and Major Pulmonary Embolism. Journal of Cardiothoracic and Vascular Anesthesia 25(5): 841-43, 2011.
Fauveaua E, Cohen A, et al: Surgical or medical treatment for thrombus straddling the patent foramen ovale: Impending paradoxical embolism? Report of four clinical cases and literature review. Archives of Cardiovascular Disease 101(10): 637-44, 2008.