Detection of fibrous strands on prosthetic mitral valves with transesophageal echocardiography: another potential embolic source.

Patients with prosthetic mitral valves (MVR) have an increased incidence of cardiac embolic events, but the causes of these emboli have not been determined. Fibrous strands, detected by transesophageal echocardiography (TEE) on the left atrial side of MVRs, may be embolic precursors in these patients. However, the incidence and clinical significance of these strands are unknown. We reviewed the charts of 76 consecutive patients with MVRs who underwent a total of 83 TEE studies between January 1991 and January 1992. Of the 83 studies, 39 (47%) were of bioprostheses and 44 (53%) were of mechanical prostheses. Strands were found in 15 studies (18%) and were significantly more common in mechanical prostheses (32% vs 3%; p < 0.001). Embolic events occurred in 53% of patients with strands compared with only 18% of those without (p < 0.01). Strands were not associated with left atrial spontaneous echo contrast, left atrial thrombi, infection, prosthetic stenosis, severity of regurgitation, or left ventricular function. No physical evidence of these strands was found in the one native and three prosthetic valves examined visually during the study at the time of surgery. The data support the hypothesis that TEE evidence of strands is associated with a higher incidence of embolic events and indicate the potential for formation of intracardiac emboli on MVRs.

Intraoperative transesophageal echocardiographic localization of tumor embolus during pneumonectomy.

We describe a patient undergoing pneumonectomy for large-cell carcinoma, which at the time of surgery was found to invade the pulmonary veins. Transesophageal echocardiography was used to confirm and localize suspected tumor embolization during surgery. Although tumor embolization from the pulmonary veins has been previously reported in the literature, this is the first case, to our knowledge, of transesophageal echocardiographic documentation of such an occurrence. The use of echocardiography in patients at potential risk for tumor involvement of the pulmonary veins is discussed.