Utility of intraoperative transesophageal echocardiography for diagnosis of pulmonary embolism

Pulmonary embolism (PE) is associated with significant perioperative morbidity and mortality. Transesophageal echocardiography (TEE) may permit direct visualization of PE or secondary signs of pulmonary artery (PA) obstruction. However, its utility in diagnosing PE in the intraoperative setting has yet to be defined. Therefore, we performed intraoperative TEE examinations in 46 patients immediately before pulmonary embolectomy. TEE examinations were reviewed for signs of thromboemboli within the right, left, and main PA, and secondary signs of acute PA obstruction (right ventricular dysfunction, moderate-to-severe tricuspid regurgitation, leftward bowing of the interatrial septum). The definitive location of thromboemboli was determined from the surgical record. Echocardiographic evidence for the presence of PE was correctly demonstrated in 46% of all patients (n = 21 of 46). However, the sensitivity for direct visualization of thromboemboli at any specific location was only 26%. TEE was least sensitive for thromboemboli in the left PA (17%). TEE evidence of right ventricular dysfunction was observed in 96%, tricuspid regurgitation in 50%, and leftward interatrial septal bowing in 98% of examinations. Therefore, the use of intraoperative TEE to diagnose acute PE via direct visualization is limited. Indirect TEE evidence of PA obstruction may be helpful in supporting a diagnosis of PE.