Transesophageal Echocardiography for the Diagnosis and Management of Massive Pulmonary Embolism

Abstract

A 48-yr-old trauma victim complained of an acute onset of dyspnea and chest pain. Pulmonary embolism was diagnosed by fast spiral computed tomography (CT) requiring emergency surgical embolectomy. After induction of general anesthesia, transesophageal echocardiography (TEE) examination showed enlargement of the right atrium and the right ventricle, bulging of the interatrial and interventricular septum, and right pulmonary artery thrombus (Fig. 1). Further TEE imaging disclosed free-floating thrombi in the right atrium and a thrombus traversing a patent foramen ovale (PFO) (Fig. 2). Continuous right-to-left shunt through the PFO and moderate tricuspid regurgitation was demonstrated with color flow Doppler (please see video loop available at www.anesthesia-analgesia.org). Pulmonary artery systolic pressure was calculated to be 65 mm Hg. After initiation of cardiopulmonary bypass and cardiotomy, 2 thrombi >2 cm in diameter were removed from the right atrium and the foramen ovale was closed. Subsequently, open pulmonary embolectomy was performed and two large thrombi were removed from the left and the right pulmonary arteries. The patient was successfully weaned from cardiopulmonary bypass and had an uneventful postoperative course.Figure 1.: TEE (midesophageal ascending aorta short-axis view) allows visualization of extracardiac and extrapulmonary location such as the superior vena cava (SVC). A thrombus (TH) is seen in the right pulmonary artery (RPA). Ao = aorta.Figure 2.: TEE (mid-esophageal bicaval view) showing two large thrombi (TH1 and TH2) in transit type A in the right atrium (RA), one of which (TH2) is entrapped in a patent foramen ovale. LA = left atrium; RV = right ventricle.Although spiral CT is the diagnostic test of choice for suspected pulmonary embolism, echocardiography can provide complimentary information, including thrombus in transit, found in 4% to 18% of cases, and PFO (1). When present, a PFO is an independent predictor of risk for stroke, major postoperative morbidity, and mortality after thromboembolectomy (2). TEE is also a reliable technique for identifying thromboembolism in extrapulmonary and extracardiac locations, including the vena cava (3). In this case, preoperative CT showed a large central pulmonary embolism extending into the pulmonary arteries, but it did not reveal intracardiac thrombi. Nonetheless, as in this case, TEE is insensitive for the detection of thrombus in the pulmonary artery (3). Regardless, TEE did provide information that led to modification of the surgical strategy, leading to direct vena caval cannulation to allow for extraction of the atrial thrombus and PFO closure.