Lambls Excrescences


Article Author:
Divya Kondamareddy


Article Editor:
Wajeed Masood


Editors In Chief:
Michael Firstenberg
Lawrence Greiten


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Frank Smeeks
Kristina Soman-Faulkner
Trevor Nezwek
Radia Jamil
Patrick Le
Sobhan Daneshfar
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Pritesh Sheth
Hassam Zulfiqar
Navid Mahabadi
Steve Bhimji
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Nazia Sadiq
Hajira Basit
Phillip Hynes
Tehmina Warsi


Updated:
6/4/2019 6:40:43 PM

Introduction

Lambl’s excrescences, a histological term describing rare cardiac growths that develop at the valvular coaptation sites of the heart which are seen as thin, hypermobile, filiform strand on an echocardiogram. These filiform strands can be noted on echocardiogram either incidentally or in association with serious complications such as embolic stroke or acute coronary syndromes after they break off and embolize to distant organs.[1]

Lambl’s excrescences are named after a Bohemian physician-scientist, Vilem Dusan Lambl (1824–1895) who first described these filiform growths on the aortic valve in 1856 in a paper titled, Papillare exkreszenzen an der semilunar-klappe der aorta (Weiner medicinische Wochenschrift). Approximately a century later, F. Margarey further described and differentiated these structures histopathologically.[2]

Of note, Vilem Dusan Lambl also takes credit for the first original description of parasite which is named after him, Giardia lamblia. He scientifically described this parasite in microscopic drawings. He also credited for giving an initial description of the morphology of bladder cancer cell and spondylosis.

Etiology

Lambl’s excrescences are slender filamentous processes that are neither sessile nor pedunculated. They occur on the endocardial surface where valvular cusps make contact with one another. Histologically, these are acellular, composed of a core made of fibro-elastic tissue covered by stroma, both densely hyalinized. This is, in turn, is covered by a single layer of endothelium. They lack vasculature, hence are devoid of granulation tissue. Lambl’s excrescences are almost always found on either native or even prosthetic heart valves. Very rarely, strands may also be seen on sites other than heart valves, for example, papillary muscles, atrial septum, and chordae tendineae.[3][4]

Lambl’s excrescences can appear as a single strand or in a cluster. They are approximately 1 mm in diameter and can reach up to a length of 10 mm. The length is stunted due to their strategic location on the valvular cusps which exposes them to high stress, especially, when located on the aortic valve which is subjected to relatively higher pressures compared to other valves. Sometimes multiple adjacent excrescences adhere to each other forming “giant Lambl’s excrescences” which can grow up to a length of 2 cm. Despite some case reports of giant Lambl’s excrescences being associated with ischemic stroke, no clear evidence in medical literature shows a correlation between the size of the strand and the risk of the embolic event.[5]

Epidemiology

Of the general population referred for a transesophageal echocardiogram (TEE) for all indications, 5.5% have valvular strands, and the number drastically increases to 40% in patients referred for cryptogenic stroke. Lambl’s excrescences are detected in both adults and children. However, the prevalence is higher in adults than children and increases with age. On echocardiogram, the prevalence peaks from age 61 to 70 and then falls after that due to aging heart valves getting more and more calcified resulting in underdetection of Lambl’s excrescences in relation to the calcified valves. Also, the incidence is relatively more common in men than women. Even though Lambl’s excrescences are reported to grow on all native and prosthetic valves,  prevalence is more on the left-sided heart valves, aortic more than mitral. Lambl’s excrescences when asymptomatic and followed over several years, appear to remain stable and intact without significant morphological changes.

Pathophysiology

Pathogenesis is not entirely clear. Aortic and mitral valves are the 2 most common locations of Lambl’s excrescences. However, ischemic events were more commonly observed in association with the ones on aortic valves as com­pared to mitral valves. It is postulated that due to high stress from blood-flow jets causing shearing forces and trauma on the heart valves endocardium develops occasional tears. These tears occur on the valvular cusps at the coaptation site followed by fibrin deposition and small thrombi formation on endothelial injury and subsequent overgrowth of endothelium over extended periods of time with advancing age.

The pathogenesis of embolic phenomena causing distal organ ischemia and injury such as ischemic stroke, acute coronary syndrome, or pulmonary embolism remains unclear. While the possibility of Lambl’s excrescences breaking off and embolizing seems obvious; however, fragments of broken valvular strands are not usually seen in the target arteries of distal organs. There is substantial evidence suggesting only an association between Lambl's excrescences and embolic events such as ischemic strokes and coronary syndromes. However, a direct causal relationship is not yet established.

History and Physical

Most cases of Lambl’s excrescences remain asymptomatic and are detected incidentally on echocardiography or on autopsy. These, especially when found on aortic valve cusps, have a higher potential of breaking off and embolize to distal organs usually in association with embolic strokes, coronary artery embolisms that results in acute coronary syndromes, or pulmonary embolisms. If large enough, even without embolization, these can cause mechanical valvular obstruction. Depending on the target distal organ affected patients can present with varied neurological and cardiopulmonary symptoms.

Patients can present with stroke-like features such as motor deficits, sensory deficits, aphasia, dysarthria, dysphagia, visual disturbances, cranial nerve palsies, ataxia to name a few. And cardiopulmonary features such as chest pain, dyspnea, diaphoresis, syncope, dizziness, nausea, vomiting, hypoxia, hypotension, arrhythmias, ischemic changes on the ECG, and elevated cardiac biomarkers can also be present.

Evaluation

Transesophageal echocardiogram (TEE) is the gold standard in detecting Lambl’s excrescences, however, due to advancement in ultrasound technology the sensitivity of TTE has also increased significantly. Alternatively, when TEE is not feasible, a high-resolution CT scan can be done. TEE detects these valvular growths and also determines its attachment to the valves, its location in relation to other cardiac structures, and its mobility. Although echocardiogram provides vivid details about the radiological morphology, a definitive diagnosis is still done through microscopic histopathological evaluation of the valvular strands when possible.

Echocardiographically, Lambl’s excrescences appear as thin, hypermobile, filiform strands on the valvular cusps’ line of closure. In the short axis view, linear strands can be seen projecting from the ventricular aspect of the aortic valve cusp tips. In the long axis view, these are seen in rows on all three aortic valve leaflets.

Treatment / Management

There are no clear evidence-based guidelines for treatment of Lambl’s excrescences. The management is primarily based upon cases reported in the medical literature.

Various approaches, both pharmacological and surgical, have been described in the management of Lambl’s excrescences. Asymptomatic ones are best managed with close observation, and with serial follow up echocardiograms. When associated with stroke, an exhaustive stroke workup to identify the potential cause of stroke should always be undertaken. This should include carotid duplex ultrasound, hypercoagulable workup, and a complete TEE assessing the ascending, transverse, and arch segments of the aorta. If the workup remains negative without any identifiable cause, then the patients can be treated with antiplatelet agents such as aspirin and clopidogrel/dipyridamole and/or anticoagulation with coumadin. In cases of recurrent strokes, when associated with Lambl’s excrescences, surgical excision may prove beneficial.

The choice between surgical debridement and conservative management depends on individual cases and their peri-operative risks. The efficacy and mortality benefit of any of these treatment measures has not been established yet.

Due to the lack of consensus, at this time it is difficult to exclude Lambl’s excrescences as a potential source of emboli in cryptogenic stroke. Medical providers should be aware of Lambl’s excrescences and at least keep them in the differential diagnosis of a patient with cryptogenic stroke unless ev­idence suggests otherwise. A TEE should always be a part of stroke workup in embolic stroke with unknown source of emboli.

Differential Diagnosis

Lambl’s excrescences have to be differentiated from fibroelastomas, valvular vegetations, myxomas, cardiac thrombi, nonbacterial vegetations, other cardiac tumors, and metastases. All of these entities have a potential for embolization to a varying degree. Distinguishing between Lambl’s excrescences and vegetations or fibroelastomas can be quite challenging. Others are reasonably well-differentiated on echocardiogram.

Lambl’s excrescences are similar histopathologically to cardiac papillary fibroelastomas. The difference is that papillary fibroelastomas are larger, more gelatinous, usually found away from the line of valve closure and covered by multiple layers of endothelial cells. Whereas, Lambl’s excrescences are smaller, located at the line of valve closure, and covered by single endothelial layer. The growth of Lambl’s excrescences may be limited due to their exposed high-stress location. In contrast, fibroelastomas are usually found on the mechanically less pressured parts of valves and other parts of the endocardium. Thus, fibroelastomas are bulkier, can be attached to the valve through a stalk or pedestal, and their surfaces may contain multiple fingerlike projections. Because fibroelastomas are larger than Lambl’s excrescences, they are therefore more prone to embolization. It is generally recommended that fibroelastomas be surgically removed.

Endocarditis related valvular vegetations are typically irregular masses that have a different echogenicity in relation to other cardiac structures. These vegetations can be adherent to valvular cusps at any site, are independent of valvular mobility and can have other pathognomonic echo findings of infection such as abscesses and valvular dehiscence besides, a clinical history suggestive of infective endocarditis and valvular dysfunction.

Nonbacterial vegetations such as the Libman Sacks thrombotic vegetations again can be located on any part of the valvular cusp. These are somewhat rounded and nonpedunculated lesions that lack independent mobility.

Prognosis

Prognosis in asymptomatic incidental findings of Lambl's excrescences is excellent. However, when these are associated with complications like ischemic stroke, acute coronary syndrome and pulmonary embolism the prognosis is independent of etiopathogenesis. In other words, irrespective of the etiology and the pathogenesis, these complications carry the same prognosis as they do with other causes.

Complications

Most cases of Lambl’s excrescences remain asymptomatic. These only get complicated when they break off and embolize to distal organs like brain, heart, and lungs. Embolic ischemic strokes, coronary embolisms causing acute coronary syndromes and pulmonary embolisms if large enough are all complications associated with Lambl’s excrescences. Sometimes if they grow into giant excrescences even without embolization can cause local mechanical valvular obstruction.[6][7][8]

Consultations

Lambl’s excrescences, once noticed on a routine echocardiogram, require a cardiology consultation for a TEE to identify, characterize, and differentiate from other similar structures. A neurology consultation would undoubtedly be beneficial when associated with an embolic ischemic stroke.

Pearls and Other Issues

In summary, Lambl’s excrescences are uncommon cardiac valvular strands now more frequently detected even on routine transthoracic echocardiograms due to advancements in ultrasonography technology. These filiform strands can be an incidental finding or can be associated with severe complications like ischemic stroke, coronary embolism, pulmonary embolism, or valvular obstruction. There is no direct, causal relationship between Lambl’s excrescences and these complications. It is only a clinical association. When detected, their proper identification and differentiation from other similar pathological entities are essential. When complications such as embolic stroke occur, a thorough workup to identify the source of emboli should be performed. Lambl’s excrescences should be a potential but last consideration in cryptogenic strokes, when associated. Various treatment modalities have been tried including observation, antiplatelet therapy, anticoagulation, and surgical excision. However, at this time, there are no specific evidence-based guidelines to assist medical professionals in the long-term management of such patients. Further systemic studies are needed.

With further medical technological advancements, Lambl’s excrescences have a higher potential of detection and, therefore, a higher risk of incidence and prevalence.

Enhancing Healthcare Team Outcomes

Lambls excrescences are rare in clinical medicine but because of their potential to cause embolic events, the condition is best managed by a multidisciplinary team that also includes cardiac nurses. Lambl’s excrescences are rare growths on the valves, expecially the aortic valves. Not much is known as to why they occur. They have the potential to embolize but many people remain asymptomatic. Because of the rarity of the disorder, there are no established guidelines on how to manage them. Anecdotal data suggests that in fit patients surgery to excise or replace the valve may be pruduent. In others, watching may be undertaken with the provision that the patient is aware of the potential for an embolic stroke.

The outlook for patients who suffer a stroke or ischemic of the bowel is guarded.


Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Lambls Excrescences - Questions

Take a quiz of the questions on this article.

Take Quiz
A 55-year-old male with a history of hypertension and stroke presented to the emergency room with difficulty in speech, right-sided weakness, ataxia, decreased sensations of the right upper and lower extremity. Blood pressure of 140/80 mmHg, heart rate of 92 bpm, respiratory rate of 16/minute, afebrile, and oxygen saturation 98% on room air. An emergent noncontrast CT scan of the brain in the emergency room showed evidence of old stroke. No acute intracranial bleed was detected. The patient was admitted with suspected acute stroke. Next, an MRI of the brain was done which showed acute multifocal ischemic stroke in the left middle cerebral artery territory. A complete stroke workup was unremarkable. Neurology consultation recommended transesophageal echocardiography, which showed some hypermobile valvular strands on the aortic valve. What is the most likely diagnosis?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 59-year-old female with a history of hypertension and stroke associated with rare valvular strands presented to the emergency department with recurrent stroke-like symptoms including left-sided weakness, altered sensations, ataxia, dysarthria, dysphagia and visual disturbances. Vital signs were stable. Initial noncontrast CT scan of the brain showed only evidence of prior stroke. After admission, an MRI of the brain was done which showed multifocal ischemic infarcts. A transesophageal echocardiogram showed persistent valvular strands. This patient was already on treatment with aspirin. What is the next best step in management?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which of the following statements regarding Lambl’s excrescences is false?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which of the following statements regarding Lambl’s excrescences is true?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which of the following is a least likely complication associated with Lambl’s excrescences?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Lambls Excrescences - References

References

Alekhin MN,Sidorenko BA, [Clinical significance of filiform structures (Lambls excrescences) on cusps of cardiac valves]. Kardiologiia. 2013;     [PubMed]
Chong-Lei R,Sheng-Li J,Rong W,Cang-Song X,Yao W,Chang-Qing G, Diagnosis and Treatment of Lambl's Excrescence on the Aortic Valve. The heart surgery forum. 2018 May 7;     [PubMed]
Phillips AL,Qureshi MY,Eidem BW,Cetta F, Lambl's excrescences in children: Improved detection via transthoracic echocardiography. Congenital heart disease. 2018 Mar;     [PubMed]
Yandrapalli S,Mehta B,Mondal P,Gupta T,Khattar P,Fallon J,Goldberg R,Sule S,Aronow WS, Cardiac papillary fibroelastoma: The need for a timely diagnosis. World journal of clinical cases. 2017 Jan 16;     [PubMed]
Kamran H,Patel N,Singh G,Pasricha V,Salifu M,McFarlane SI, Lambl's excrescences: A case report and review of the literature. Clinical case reports and reviews. 2016;     [PubMed]
Girolami I,Eccher A,Gilioli E,Novelli L,Di Stefano G,Brunelli M,Cima L, Mesothelial/monocytic incidental cardiac excrescences (MICE): report of a case and review of literature with focus on pathogenesis. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology. 2018 Sep - Oct;     [PubMed]
Marstrand P,Jensen MB,Ihlemann N, Valvular Excrescences: A Possible Transient Phenomenon. Case reports in cardiology. 2015;     [PubMed]
Davogustto G,Fernando RR,Loghin C, Lambl's excrescence, migrainous headaches, and     [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Surgery-Cardiac. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Surgery-Cardiac, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Surgery-Cardiac, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Surgery-Cardiac. When it is time for the Surgery-Cardiac board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Surgery-Cardiac.