Case report: optimizing intraoperative detection of pulmonary embolism using contrast-enhanced echocardiography

Perioperative pulmonary embolism (PE) is associated with significant morbidity and mortality. Intraoperatively, the clinical management of patients with PE can be enhanced by the use of transesophageal echocardiography (TEE) to visualize emboli, assess pulmonary artery (PA) anatomy, and monitor the function of the right ventricle. However, the sensitivity of intraoperative TEE to detect thromboemboli is reported to be below 50%. In this report, we describe the use of contrast-enhanced TEE (CE-TEE) to improve the visualization of PE.

A 44-yr-old female with chronic thrombo-embolic pulmonary hypertension was scheduled for pulmonary thromboendarterectomy. The precardiopulmonary bypass TEE exam demonstrated signs of PA obstruction and right ventricle dysfunction, but the borders of the thrombus in the right PA were only minimally visualized. Perflutren lipid microspheres, composed of octafluoropropane encapsulated in an outer lipid shell, were injected as a 0.3 mL iv bolus, while visualizing the right PA with harmonic ultrasound imaging. The CE-TEE image clearly visualized a large mobile thrombus along with a distinct pattern consistent with pulmonary flow obstruction. The postcardiopulmonary bypass CE-TEE confirmed thrombus evacuation and absence of PA flow abnormalities.

Contrast-enhanced-TEE may decrease operator dependency and increase the sensitivity necessary to detect central, surgically accessible PE.