Lambl's excrescence on aortic valve detected by transesophageal echocardiography

A 69-yr-old woman was scheduled for mitral valve replacement and coronary artery bypass graft surgery. Her medical history included mitral stenosis and a single coronary artery disease. She was given anticoagulation therapy for paroxysmal atrial fibrillation. Preoperative transthoracic echocardiography demonstrated mitral stenosis and trivial aortic regurgitation but no abnormal intracardiac structures. After induction of general anesthesia, we placed a transesophageal multiplane probe (Philips Electronics, Eindhoven, Netherlands). Two dimensional transesophageal echocardiography (TEE) confirmed doming and calcification of the mitral valve. Color flow Doppler imaging in the midesophageal longand shortaxis views demonstrated a trivial eccentric jet of aortic regurgitation from the commissure between the right and left coronary cusp. The midesophageal long-axis view showed the presence of a filamentous structure on the aortic valve (AV), which was not noticed by the preoperative transthoracic echocardiography. The structure was very thin, approximately 10-mm long, and was flapping in the aortic root (Figs. 1A and B), (Video clip 1; please see video clip available at www.anesthesia-analgesia.org). We first performed mitral valve replacement with a mechanical valve from the right atrium via the atrial septum. Second, we performed coronary artery bypass to the left anterior descending branch with the left internal thoracic artery. Third, we opened the ascending aorta to observe the flapping structure. The structure was attached to the free edge of the left coronary cusp. We decided to resect it to avoid systemic embolization and to confirm the diagnosis. The structure was a 12-mm fibrous tissue (Fig. 2). We presumed it was a flapping piece torn from the commissure between the right and left coronary cusp along the edge of the left coronary cusp. Because pathological examination revealed that the structure consisted of connective tissue covered by a single layer of endothelial cells, we diagnosed Lambl’s excrescence. After uneventful weaning from cardiopulmonary bypass, subsequent TEE confirmed that the filamentous structure on the AV was no longer present and the degree of aortic regurgitation remained trivial. The differential diagnoses of the flapping structure in the AV included imaging artifact, vegetation, thrombus, redundant leaflet, flap due to aortic dissection, papillary fibroelastoma, and Lambl’s excrescence. The TEE imaging from multiple planes excluded a possibility of imaging artifact. We easily excluded the diagnosis of vegetation, because inflammatory findings and a history of infections endocarditis were absent. We also excluded thrombus because the structure was very thin and filamentous. We dismissed the possibility of a redundant leaflet or a flap due to aortic dissection, because three cusps of the AV were depicted clearly by TEE. The distinction between papillary fibroelastoma and Lambl’s excrescence was particularly difficult. Papillary fibroelastoma typically appears on echocardiography as a small pedunculated, homogenous, well-demonstrated mobile mass attached by a small stalk. Although these findings may be applied to Lambl’s excrescence, the stalk of papillary fibroelastoma has a broader base This article has supplementary material on the Web site: www.anesthesia-analgesia.org.