Giant Aortic Lambl's Excrescence

Abstract

Background

Lambl's excrescences (LEs) are thin, filamentous valvular strands that are usually small and asymptomatic, however when they are large and mobile, they can cause embolic or obstructive events.

Case Summary

A 59-year-old man presented with recurrent angina-like chest pain. Coronary angiography showed an intermediate lesion in the left anterior descending artery without hemodynamic relevance. Echocardiography revealed a highly mobile, 20- to 30-mm filamentous structure attached to the left coronary cusp, intermittently prolapsing toward the left coronary ostium and causing moderate aortic regurgitation. Surgical excision and aortic valve replacement were performed through a ministernotomy. Symptoms resolved, and histopathology confirmed a giant LE.

Discussion

Giant or hypermobile LEs can dynamically obstruct coronary ostia, mimicking atherosclerotic angina, even without significant coronary vascular disease. Surgical treatment is recommended when lesions are large, symptomatic, or associated with an increased risk of embolism.

Take-Home Message

Large LEs may cause coronary obstruction; multimodality imaging is essential, timely surgical removal provides relief and prevents ischemic or embolic complications.

Graphical Abstract

History of Presentation

In February 2024, a 59-year-old man experienced recurrent episodes of angina-like chest pain and was referred to the hospital. Cardiac catheterization revealed intermediate coronary artery sclerosis involving the proximal left anterior descending artery, without hemodynamically significant stenoses (fractional flow reserve: 0.84) (Figure 1A, Video 1) and without progression compared with an angiography from 2020. Transthoracic echocardiography performed during the hospital stay revealed a mobile, strand-like structure, approximately 16 mm in length, attached to the left coronary cusp of a trileaflet aortic valve, prolapsing alternately into the sinus of Valsalva and the left ventricular outflow tract. Further valve analysis revealed mild to moderate aortic regurgitation, with no other significant valve pathologies. Left ventricular function was normal, with no signs of ischemic infarction. The patient denied fever, chills, or weight loss. He had no history of neurological deficits or visual disturbances. Blood cultures were negative, and laboratory findings revealed no evidence of an infectious process.

Take-Home Messages

• •Giant Lambl's excrescences are rare but clinically relevant lesions that may intermittently obstruct the coronary ostia, requiring precise multimodality imaging for diagnosis.
• •Timely surgical excision is safe and effective, providing definitive symptom relief and preventing recurrent ischemic or embolic events.

Figure 1.

Exclusion of Significant Coronary Disease and Identification of Cardiac Mass

(A) Coronary angiography showing intermediate coronary artery sclerosis involving the proximal LAD, without showing hemodynamically significant stenoses (FFR: 0.84). See also Video 1. (B) Intraoperative TEE (midesophageal long-axis view) indicates the giant, 1.6 cm–diameter strand (arrow) attached to the left coronary cusp, seen prolapsing toward the left ventricular outflow tract. See also Video 2. FFR = fractional flow reserve; LAD = left anterior descending artery; TEE = transesophageal echocardiography.

Based on these findings, we suspected that the prolapsing strand-like structure was highly indicative of transient obstruction of the coronary ostium. Given this suspicion and the increased risk of additional thromboembolism, stroke, or progressive valvular dysfunction, surgical removal was indicated.

Operative Technique

Intraoperative transesophageal echocardiography offered enhanced resolution. It confirmed a filamentous structure measuring 25 to 30 mm, firmly attached at the left coronary cusp margin, which prolapsed into the left ventricular outflow tract during diastole (Figure 1B, Video 2). After establishing cardiopulmonary bypass through a partial upper (mini) sternotomy, the ascending aorta was opened after the administration of del Nido solution for cardioplegic arrest. Direct inspection revealed a strand-shaped, beige-colored, 20 mm–long appendage, consistent with a giant Lambl's excrescence (LE) (Video 3). The left coronary cusp appeared restricted in its mobility, explaining the moderate aortic regurgitation. Because a repair was unlikely to restore full functionality, the native valve leaflets and the attached excrescence were excised. The excised lesion was sent for histopathological and microbiological study. There were no clinical signs of endocarditis. After debriding the annulus and irrigating the left ventricle, an Edwards Inspiris Resilia bioprosthesis (size 23) was implanted using noneverting mattress sutures. The aortotomy was closed in a running fashion. Upon releasing the cross-clamp, the heart resumed sinus rhythm easily, and the patient was weaned from cardiopulmonary bypass without difficulty.

The patient's postoperative course was uneventful, with no neurological deficits or recurrent angina pectoris, and he was discharged home on postoperative day 8.

Pathological analysis confirmed a long, fibrous strip composed of collagen and elastic fibers covered by endothelium, consistent with a giant LE (Figure 2). When fully unfurled, it measured around 20 × 5 mm. There was no microscopic evidence of infection or malignancy. Cultures submitted to microbiology were negative.

Figure 2.

Pathological Evaluation of the Excised Lambl's Excrescence

(A) Macroscopic photograph showing the 3.0 × 2.0 × 0.3 cm–sized left cusp of the excised aortic valve with a strand-shaped, beige-colored, 2.0 cm–long appendage. (B) Microscopic findings show a fibrous strip composed of collagen and elastic fibers covered by endothelium, consistent with a giant Lambl's excrescence.

Discussion

Lambl's excrescences, initially described by Vilém Dusan Lambl in 1856, are thin, filamentous extensions frequently located along valve closure lines. They originate from minor valvular endothelial damage and may accumulate layers of fibrin and collagen. Most are small and clinically silent, discovered incidentally.¹ However, large or highly mobile lesions are recognized risk factors for embolic events, potentially involving the cerebral, coronary, or peripheral vasculature. While small, asymptomatic strands often warrant observation and periodic echocardiographic follow-up, larger lesions associated with valvular dysfunction or recurrent embolic phenomena may merit surgical resection.2, 3, 4, 5

Only a handful of cases have linked LE directly to angina or myocardial infarction. In 1999, Dangas et al⁶ described giant LEs that intermittently occluded the left coronary ostium, causing a non–Q wave infarction. Quinson et al⁷ reported dynamic obstruction of the right coronary ostium with exertional angina that resolved after excision. More recently, Safa et al³ documented an ST-segment elevation infarction from coronary embolization of an LE fragment in 2021. These reports, together with smaller series and reviews, confirm that LEs can precipitate coronary ischemia even in the absence of flow-limiting atherosclerosis.

Our patient had an intermediate left anterior descending artery stenosis without hemodynamically relevant obstruction on invasive physiological assessment. This negative coronary work-up rendered a fixed atherosclerotic mechanism unlikely and prompted consideration of alternative causes of myocardial ischemia.

Transesophageal echocardiography subsequently demonstrated a large, highly mobile LE dynamically approaching and intermittently covering the left coronary ostium during diastole, providing a plausible mechanical explanation for transient coronary flow limitation. The patient's symptoms resolved after aortic valve replacement, without coronary revascularization, which is consistent with a nonatherosclerotic mechanism.

Regarding alternative imaging or functional testing, modalities such as cardiac computed tomography or cardiac magnetic resonance imaging may provide complementary anatomical or perfusion information; however, their temporal resolution and ability to depict thin, highly mobile valvular structures are limited. Importantly, none of these techniques are currently established to reliably demonstrate intermittent, short-lasting coronary ostial obstruction. In this context, targeted transesophageal echocardiography with Doppler assessment of the coronary ostium may represent the most promising approach to directly assess dynamic coronary flow impairment in future cases.

Conclusions

This case illustrates that LE can masquerade as typical atherosclerotic angina. Once significant coronary artery disease has been excluded, careful echocardiographic assessment may help identify rare dynamic mechanisms of coronary obstruction. Prompt surgical removal of the offending LE provided definitive symptom relief and may have prevented recurrent ischemic or embolic events.

Ethics Statement

The authors confirm compliance with the Ethics Committee of the TUM School of Medicine and Health, including obtaining patient consent, and affirm adherence to the ethical principles outlined in the Declaration of Helsinki.

Funding Support and Author Disclosures

Dr Krane is a physician proctor and a member of the medical advisory board for Sanamedi and a physician proctor for Peter Duschek, a medical consultant for Evotec and Moderna, and has received speakers' honoraria from Edwards, AtriCure, Medtronic, and Terumo. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Appendix

Video 1

Coronary Angiography Showing Intermediate Coronary Artery Sclerosis Involving the Proximal Left Anterior Descending Artery, Without Showing Hemodynamically Significant Stenoses (FFR: 0.84)