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Lambl's excrescences are filiform fronds that occur at sites of valve closure. They originate as small thrombi on endocardial surfaces (where the valve margins contact) and have the potential to embolize to distant organs. We describe the case of a 61-year-old woman who presented with repeated episodes of stroke. She was found to have Lambl's excrescences on all 3 leaflets of the aortic valve. After all other possible causes of stroke were ruled out, she underwent successful open heart surgery for débridement of these excrescences. The histopathologic diagnosis was consistent with Lambl's excrescences. Our patient did not have any cerebrovascular embolic event after surgery.
Because of its high sensitivity to detect excrescences, transesophageal echocardiography should be included in the diagnostic assessment of all patients who have experienced strokes. Asymptomatic patients who are found to have evidence of Lambl's excrescences should be monitored closely. If there is evidence of 1 cerebrovascular accident in a patient with Lambl's excrescences, anticoagulation is advised. Any suggestion of a 2nd such episode should lead to operative removal of Lambl's excrescences.
Lambl's excrescences (LE) are filiform fronds that occur at sites of valvular closure. They may be found without any other evidence of cardiac disease.1,2 They originate as small thrombi on endocardial surfaces where the valve margins make contact. These are the sites of minor endothelial damage, due to wear and tear. These fronds have acellular fibrous axes, which display a concentric granular pattern caused by the successive layering of acid mucopolysaccharide matrix.3
The complex form of LE is “giant LE,” which results from the adherence of multiple adjacent excrescences that grow large.3,4 Lambl's excrescences are a fairly rare disease entity. In our search of the MedLine database for “Lambl's excrescences”, “excrescences,” and “heart valve vegetations,” we found only 7 clinical reports. Herein, we recount our recent experience and review the other reports in the literature.
In February 2004, a 61-year-old woman arrived at work late, because she “got lost while driving.” Her coworkers noted that she appeared confused and could not remember her password or how to log on to the computer. They took her to the emergency room. The patient remembered feeling light-headed, but she denied loss of consciousness, shortness of breath, blurry vision, weakness in any body part, nausea, or vomiting. Her relevant medical history included well-controlled diabetes for 20 years and hypertension for 5 years. The patient's medical records revealed that she had been to the emergency room 4 times during the past year, with complaints of falls. Previous magnetic resonance imaging (MRI) of her brain had revealed periventricular, deep microvascular change in the corona radiata, and an old lacunar infarct in the right thalamus. On examination, she was afebrile, her vital signs were stable, and her neurologic exam yielded normal results. Her Mini Mental Status Examination (MMSE) score was 28/30. All of her laboratory values were normal, including troponins and the rapid plasma reagin test. Computed tomographic scanning of the head showed white-matter periventricular ischemic changes and tiny lacunar infarcts in the right thalamus (Fig. 1).
Magnetic resonance imaging (Fig. 2) showed 3 enhancing lesions suspect for meta-static disease and left middle cerebral artery stenosis. Two-dimensional echocardiography showed normal left ventricular function, a left ventricular ejection fraction of 0.60, and a thick (but nonspecific) mitral leaflet. Computed tomography of the chest showed cardiomegaly and bilateral pleural effusions.
A repeat MRI performed 4 days after admission showed a new right pontine in-farct. Ultrasonography of the bilateral carotid arteries showed internal carotid artery stenosis: 59% on the right and 50% on the left. Transesophageal echocardiography (TEE) showed linear mobile densities on the aortic leaflets, consistent with LE (Fig. 3).
A multidisciplinary decision was made for operative intervention. An aortotomy was performed. There were multiple 1- to 4-mm projections on the underside and edges of the aortic valve. The projections were most prominent on the noncoronary leaflet. The largest excrescence was at the bifurcation of the noncoronary and right coronary cusps. The excrescences were removed. The patient was weaned from cardiopulmonary bypass without difficulty. An echocardiogram was performed on postoperative day 9; mild aortic insufficiency was evident, but the excrescences were no longer present.
Postoperatively, the patient was hemodynamically stable. Her mental status was back to baseline, which meant that she was forgetful. She had brief episodes of atrial fibrillation, for which she was started on warfarin. She was discharged from the hospital on postoperative day 9. Histology showed multiple papillary fronds containing central fibroelastic and hyalinized stroma, with focal endothelial lining, consistent with LE (Fig. 4). She was seen 10 days after discharge. She reported feeling fine and denied any new episodes of confusion or forgetfulness. The patient has not had additional central nervous system events during the past year.
Lambl's excrescences were first described by Vilém Dušan Lambl,5 a Bohemian physician. In atrioventricu-lar valves, LE are found at the site of valve closure. In semilunar valves, they can occur anywhere on the valve. Larger lesions are called cardiac papillary fibro-elastomas. Cardiac papillary fibroelastomas are present on valves, away from valvular lines of closure, and also on the endocardial surfaces of the atria and ventricles.5 Smaller, more common lesions near lines of valvular closure are termed LE. Lambl's excrescences are multiple and broader based.
Cha and colleagues6 described the case of a 54-year-old woman whose echocardiogram showed an aortic valvular mass. After surgical removal of the mass, the histopathologic diagnosis was LE. Fitz-gerald and associates7 described the case of a 70-year-old man who presented with embolus to the popliteal artery. Pathologic examination of the specimen revealed embolized LE. Nighoghossian and coauthors8 described 3 patients with ischemic stroke, whose stroke workups yielded normal results except for mitral valve lesions on TEE. One patient underwent surgery, and the other 2 were managed conservatively. These last 2 patients had 2nd strokes within 6 months, leading to surgery in these patients as well. The histologic reports for all 3 patients suggested LE. Voros and coworkers9 reported the 1st case of echocardiographically detected LE, on the pulmo-nary valve of a 72-year-old man who presented with stroke. Quinson's group10 described the case of a 64-year-old woman with angina, in whom echocardiography and angiography suggested obstruction of the right coronary ostium by a valvular tumor. Excison of the tumor showed LE. Berent and colleagues11 described the case of a 44-year-old woman who presented with fatigue. Transesophageal echocardiography showed an echogenic mass on the aortic valve, which was removed surgically. Histologic examination showed LE.
Most patients with LE are asymptomatic. However, LE—found mostly on aortic valve leaflets—can break apart and embolize. When they embolize to the brain, they can cause strokes. Potential causes of a cerebrovascular accident (CVA) should be identified by duplex ultrasonography of the carotid arteries and by TEE of the ascending, transverse, and arch segments of the aorta. Hypercoagulable states should be ruled out. We recommend TEE as a component in the causal evaluation of any stroke, because it is more sensitive than transthoracic echocardiography.
If the patient's history indicates multiple CVAs, he or she should be offered débridement of the excrescences. The patient's cardiac rhythm and the distribution and size of the CVA determine the postoperative anticoagulation regimen, which includes aspirin plus clopidogrel or warfarin.
Patients who have LE and have experienced 1 CVA should be treated conservatively with anticoagulation. A 2nd CVA should lead to excision of the LE. Asymptomatic patients should be monitored closely.
Address for reprints: Faisal Aziz, MD, Department of Surgery, Munger Pavilion, Suite 211, New York Medical College, Valhalla, NY 10595. E-mail: moc.oohay@611zizalasiaf