Thoracoscopic Resection of a Giant Right Atrial Appendage Aneurysm in an Adult: A Rare Case Report

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Introduction 

Aneurysm of the right atrial appendage (RAA) is an extremely rare cardiac malformation, typically congenital, although it may also result from right atrial overload due to conditions such as pulmonary hypertension, a patent foramen ovale, or right heart failure. There are very few published cases, and as a result, it has not been thoroughly studied. It carries the risk of serious complications such as tachyarrhythmias, embolism, and rupture. To date, open-heart surgery is the only effective treatment reported in the literature. Here, the authors report a case where it was corrected thoracoscopically. 

Case Report 

A 22-year-old woman and mother of two children, presented with mild dyspnea on exertion, palpitations, and chronic vague thoracic pain. A transthoracic echocardiogram revealed a large aneurysm of the right atrial appendage during the second week of gestation with her second child. The imaging study was completed with cardiac magnetic resonance, where the dimensions of the aneurysm were measured at 9.5 × 4.5 cm. 

She was operated on using a totally minimally invasive thoracoscopic approach via a right anterior submammary minithoracotomy. Circulation was supported by extracorporeal circulation through the right femoral vessels after heparinization. On a beating heart, the aneurysm of the right atrial appendage was excised, and the atrial wall was reapproximated with nonabsorbable running sutures. A patent foramen ovale was excluded by a bubble test intraoperatively. 

After excision, the dimensions of the right atrium were 3 × 2 cm. The patient was extubated in the operating room immediately after the procedure, recovered well during an uneventful postoperative period, and was discharged on postoperative day four. 

Discussion 

Right atrial appendage aneurysm (RAAA) is a markedly rare congenital or idiopathic anomaly—with fewer than 20 thoroughly published adult cases. The first was published in 1947 as a postmortem finding of a ruptured RAAA in a 30-year-old man died suddenly(1).. It most commonly presents in the third decade of life, with equal prevalence among males and females. Dyspnea and palpitations are the most frequent presenting symptoms, and echocardiography typically establishes the diagnosis (2). RAAA poses a risk of serious complications, including atrial tachyarrhythmia (e.g., atrial flutter, fibrillation), thromboembolism, and even rupture. Arrhythmias in this context are often refractory to medical therapy or catheter ablation (3). Published cases report an average aneurysm size of approximately 8.8 × 6.1 cm. Larger aneurysms have been successfully managed surgically with excellent outcomes (4). Minimally invasive approaches, such as video-assisted thoracoscopic surgery (VATS), offer distinct advantages over traditional sternotomy, including reduced wound morbidity, shorter recovery time, and potentially fewer postoperative complications (5). 

While almost all previously reported RAAA resections were performed via median sternotomy with cardiopulmonary bypass, this case demonstrates the feasibility and safety of a thoracoscopic approach complemented by femoral vessel extracorporeal support. Given the potential for significant morbidity, even asymptomatic aneurysms may warrant resection when risk factors are present or when aneurysms are large or growing. In all reported symptomatic cases, surgical correction has resulted in the resolution of symptoms. 

Conclusion 

This case underscores that symptomatic RAAA can be safely and effectively managed using a minimally invasive thoracoscopic technique. The result was prompt recovery, restoration of normal cardiac anatomy and function, and an uneventful postoperative period. The authors advocate that, in selected patients, thoracoscopic resection under appropriate extracorporeal support can be considered a viable alternative to conventional surgical approaches. 

References

1. ABDALLA H. Ruptured aneurysm of right auricle. Br Med J. 1947 Mar 15;1(4497):355. doi: 10.1136/bmj.1.4497.355-c. PMID: 20343483; PMCID: PMC2052819.
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3. Sivakumaran L, Sayegh K, Mehanna E, Sanchez FW, Fields J, Cury R. Use of cardiovascular magne5c resonance in the evalua5on of a giant right atrial appendage aneurysm: a case report and review of the literature. BMC Res Notes. 2017 Dec 4;10(1):681. doi: 10.1186/s13104-017-3046-2. PMID: 29202817; PMCID: PMC5715645.
4. Aryal MR, Hakim FA, Giri S, Ghimire S, Pandit A, Bhandari Y, Acharya YP, Pradhan R. Right atrial appendage aneurysm: a systema5c review. Echocardiography. 2014 Apr;31(4):534-9. doi: 10.1111/echo.12510. Epub 2014 Jan
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5. Hiraoka A, Tachibana H, Yoshitaka H, Sakaguchi T. Giant aneurysm of the right atrial appendage repaired by minimally invasive approach. J Card Surg. 2019 Nov;34(11):1352-1353. doi: 10.1111/jocs.14206. Epub 2019 Sep 3. PMID: 31478249.

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