A rare case of left atrial appendage aneurysm

doi:10.21203/rs.3.rs-3149553/v1

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Case Report

A rare case of left atrial appendage aneurysm

https://doi.org/10.21203/rs.3.rs-3149553/v1

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Background

Left atrial appendage aneurysm (LAAA) is a rare cardiac mass. There are usually no specific symptoms, and a few patients see a doctor because of palpitations, chest tightness, dyspnea and other symptoms. At present, only a few cases have been reported. In this case, a rare case of left atrial appendage aneurysm was reported, and the cases reported in previous literature were systematically reviewed.

Case presentation

A 20-year-old male was admitted to our hospital because of the discovery of pericardial cyst by physical examination for 2 years. Echocardiography showed that the cystic dark area of left ventricular lateral wall and anterolateral wall was considered pericardial cyst and mild mitral regurgitation. After improving the relevant examination and excluding contraindications, the resection of benign aneurysm of left atrium was performed under cardiopulmonary bypass. The postoperative pathological results showed that (left atrial appendage) fibrous capsule wall-like tissue with focal lining of flat epithelium, consistent with benign cyst.

Conclusion

Left atrial appendage aneurysms are rare and occult, which are generally found by accidental physical examination. When its location is poor or the volume is too large, there will be symptoms of compression or arrhythmia, thrombosis and other concomitant symptoms. At present, the only and effective radical treatment for LAAA is surgical resection.

Congenital left atrial appendage malformation

left atrial appendage aneurysm

cardiac benign aneurysm

Most of the cardiac space occupying diseases are benign, and most of them are myxomas. Left atrial appendage aneurysm (LAAA) is a rare cardiac mass, which is divided into congenital and acquired types. Congenital left atrial appendage aneurysm is caused by atrial fiber dysplasia.^[1] While the acquired is often caused by gradually dilated of left atrial appendage due to increased left atrial pressure.^[2] Foale et al put forward the diagnostic criteria of congenital left atrial appendage aneurysm in 1982: (1) originated from normal atrioventricular; (2) clear communication with atrial cavity; (3) located in the pericardium; (4) left ventricular distortion caused by aneurysm.^[3] Williams divided this disease into two types: extrapericardial type and intrapericardial type.^[4]

The patient in this case is a 20-year-old male who was admitted to our hospital because of the discovery of pericardial cyst by physical examination for 2 years. There was no obvious discomfort and no special positive signs. The chest X-ray examination (figure 1) showed that the upper segment of the heart was bulging. Echocardiographic findings (figure 2): cystic dark area of left ventricular lateral wall and anterolateral wall, considering pericardial cyst, mild mitral regurgitation. Chest enhanced CT (figure 3) shows cystic dilatation of the left edge of the heart and aneurysm-like dilatation of the trunk of the pulmonary vein. Pulmonary vein CTA (figure 4) indicates that the local aneurysm-like dilatation of the left atrium is prominent. No more obvious abnormality was found in the rest results of laboratory tests and examinations. Preliminary diagnosis: pericardial cyst, congenital atrial appendage malformation.

According to the analysis of symptoms, signs, auxiliary examination and medical history, although this patient had mild mitral regurgitation, the texture and opening or closure of the mitral valve were good, so the secondary left atrial appendage aneurysm could be excluded. The patient's pericardium was continuous and intact, so was finally diagnosed as intrapericardial congenital left atrial appendage aneurysm.

After improving the relevant preoperative preparation, selective resection of beating left atrial benign aneurysm under general anesthesia and cardiopulmonary bypass was performed. Conventional median thoracotomy was selected. During the operation, the left atrial appendage showed aneurysm-like dilatation, the size of which was about 7*7cm (figure 5). The dilated aneurysm oppressed the left superior pulmonary vein and the main pulmonary artery, its wall was thin, and the blood flow was slow. With the assistance of cardiopulmonary bypass, the auricular aneurysm was explored to the root, and the pedicle-like structure was seen, so the cutting stapler and gold nail were used to remove the aneurysm cyst pedicle (figure 6). After confirming that the circumflex branch vessel was not affected and there was no obvious bleeding, local reinforcement and suture was performed. The operation ended after being confirmed by transesophageal echocardiography. The operation was completed after being confirmed by transesophageal echocardiography. The operation went smoothly and the patients were sent to the intensive care unit after the operation. The resected specimens (figure 7) were sent to routine pathology, and the results showed that (left atrial appendage) fibrous sac wall-like tissue with focal lining of flat epithelium, in accordance with benign cysts (figure 8).

The patient recovered smoothly after operation, the tracheal intubation was removed on the first day after operation and transferred to the general ward on the second day. Echocardiography before discharge showed mild mitral regurgitation after resection of left atrial appendage aneurysm. No obvious abnormal changes were found in coronary artery CTA and other laboratory and auxiliary examinations. The patient was successfully discharged from the hospital on the sixth day after operation. One month after operation, echocardiography showed mild tricuspid regurgitation after resection of left atrial appendage aneurysm.

LAAA is a relatively rare cardiac malformation characterized by local or diffuse dilatation of the left atrial appendage.^[5] So far, only more than 100 cases of LAAA have been reported, of which Dimond was the first to discover this type of disease and reported it in 1960.^[6] In terms of epidemiological characteristics, LAAA does not have a specific age or sex distribution, nor does it have a special genetic history.

Simple left atrial appendage aneurysms usually have no specific symptoms, most patients are found by physical examination, and some patients are diagnosed in hospital because of palpitations, chest tightness, dyspnea and other symptoms. When the atrial appendage aneurysm is large or poorly located, it can oppress the surrounding tissues and organs, resulting in dyspnea, angina pectoris, chronic heart failure and other symptoms; long-term left atrial pressure rise, left atrial dilatation and other pathophysiological changes will lead to mitral valve disease, arrhythmia, etc.; slow blood flow in LAAA is easy to form thrombus, if the thrombus falls off, it will lead to a series of embolic symptoms.^[1,7-8] This patient did not have any special related symptoms, and the aneurysm was found accidentally by routine physical examination. In addition, it is worth mentioning that we usually think that most of the patients diagnosed with LAAA with atrial fibrillation have larger aneurysm and longer course of disease, but Aryal MR et al found that atrial fibrillation / atrial flutter is the only variable significantly related to thrombosis, but not related to age, sex, type and size of LAAA.^[1]

Cardiac ultrasound is the main auxiliary examination method of LAAA. Compared with transthoracic ultrasound, transesophageal ultrasound can understand the internal structure of the heart more clearly and accurately and whether there are other organic or functional complications.^[9] Chest CT and cardiopulmonary CTA can directly understand the anatomical structure, relative position and compression of atrial appendage aneurysms. Cardiac MRI and PET-CT are seldom used in clinic.^[5] The preoperative examination of this patient included routine cardiac ultrasound and chest X-ray. In order to more intuitively understand the shape, location and related anatomical relationship of the atrial appendage aneurysm, we also carried out targeted chest plain scan, enhanced scan and lung CTA examination.

At present, there are no specific drugs for the treatment of LAAA, but according to a series of concomitant diseases, anticoagulants, antiarrhythmic drugs, diuretics and other drugs can be given. Once the atrial appendage aneurysm is found, selective resection is recommended. Surgical resection is the radical treatment of left atrial appendage aneurysm, and it is also the current clinical consensus.^[5] The surgical options include non-cardiopulmonary bypass, cardiopulmonary bypass or off-pump aneurysm resection, and the incision includes median thoracotomy, left small incision and so on. At present, the most commonly used method is transsternal median thoracotomy for aneurysm resection under cardiopulmonary bypass and pericardial reconstruction if necessary. [8] This patient with left atrial appendage aneurysm does not have any concomitant symptoms, and there is no need for special drug treatment before and after operation. Surgical resection is the only and effective treatment for this patient. After preoperative multi-evaluation and intraoperative exploration, the shape of the left atrial appendage aneurysm in this patient was complete, the boundary between the aneurysm and the periphery was clear, and the pedicle of the aneurysm was obvious, so we chose to cut and suture directly with a cutting suture device under the condition of beating heart. This kind of beating-up resection of left atrial appendage aneurysm assisted by cardiopulmonary bypass does not need to go through the process of cooling, rewarming and cardiac arrest, re-beating, which shortens the operation time and reduces the stress degree of patients to a certain extent, which is conducive to the rapid recovery of patients after operation.

The postoperative prognosis of patients with atrial appendage aneurysm is good. There are no reports of recurrence, thromboembolism, arrhythmia and other complications after resection so far. [1] No obvious abnormality was found in the postoperative reexamination and the reexamination of 1 month, 6 months and 1 year after discharge, and the recovery was good.

To sum up, as a rare special case, left atrial appendage tumor has the characteristics of concealed incidence, single treatment, good prognosis and so on. But there are few studies on atrial appendage aneurysms at present. Is there a direct relationship between the size and shape of atrial appendage aneurysms and their complications? What is the standard of surgical treatment? Is there the possibility of spontaneous rupture of an aneurysm? There is no detailed research report on these issues, and a unified consensus has not yet been reached. The understanding and research on LAAA still need to be further understood.

LAAA

Left atrial appendage aneurysm

Ethics approval and consent to participate

Written informed consent was obtained from the patient to participate in this article.

Consent for publication

Written informed consent for publication of clinical details and clinical images was obtained from the patient. A copy of the consent form is available for review by the Editor of the journal.

Availability of data and materials

Data sharing is not applicable to this article as no datasets were generated or analysed.

Competing interests

The authors declare no competing interests.

Funding

We received neither funding nor sponsorship for this study nor any publication of this article.

Author contributions

KQ have made contributions to drafting article, revision of article, and data interpretation. PT have made contributions to drafting article and reviewing. LPS is responsible for reviewing and revision. LM is responsible for project administration, supervision, designing of the work, critical revision of article, and final approval of the version to be published. All authors read and approved the final manuscript.

Acknowledgements

Not applicable.

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Wang HQ, Zhang Z, Yang H, Wu S, Fu YH, Song ZM, Wan F. A Huge Congenital Left Atrial Appendage Aneurysm. Chin Med J (Engl). 2017;130:3011–2.
Foale RA, Gibson TC, Guyer DE, Gillam L, King ME, Weyman AE. Congenital aneurysms of the left atrium: recognition by cross-sectional echocardiography. Circulation. 1982;66:1065–9.
Williams WG. Dilatation of the Left Atrial Appendage. Br Heart J. 1963;25:637–43.
Cuenca Castillo J. Left Atrial Appendage Aneurysm: Knowledge and Gaps. JACC Case Rep. 2021;3(18):1930–1.
Dimond EG, Kittle CF, Voth DW. Extreme hypertrophy of the left atrial appendage: the case of the giant dog ear. Am J Cardiol. 1960;5:122–25.
Khanra D, Tiwari P, Kodliwadmath A, Duggal B. Giant left atrial appendage aneurysm and atrial fifibrillation: chicken or the egg? BMJ Case Rep. 2019;12(8):e231300.
Sankhyan LK, Chowdhury UK, Chauhan A, et al. A novel technique of repair of congenital left atrial appendage aneurysm using bovine pericardial patch. J Integr Cardiol Open Access. 2019;1(1):3–7.
Belov DV, Moskalev VI, Garbuzenko DV, Arefyev NO. Left atrial appendage aneurysm: A case report. World J Clin Cases. 2020;8(19):4443–9.

No competing interests reported.

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A rare case of left atrial appendage aneurysm

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Abstract

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Background

Case presentation

Discussion

Conclusion

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