Background: Aneyrysm of Left Atrial Appendage (LAAA) is a rare cardiac anomaly. It was first identified in 1960 (1). As severe complications like thromboembolic events, rhythm disorders and CCF surgical management is recommended. The authors presented a 24 years old boy  who  was hospitalized with a LAAA. It was detected incidentally by  CT Scan of the chest. The patient underwent operation with removal of aneurysm under cardiopulmonary bypass.

Case presentation: Masum Billah of 21 years boy  was attended in outpatient department with non specific presentation. A Thoracic X-ray was done and suspected as a case of posterior mediastinal mass. A contrast CT scan was done and diagnosed as a case of giant LAAA (90 mm × 75 mm). For Cardiac evaluation Echocardiography was done and revealed large 90 mm x 70 mm   LAAA enlarged compressing the left ventricle. The other findings of Echocardiography was within normal limit. Doing all necessary investigations the patient was scheduled to undergo surgery on 04/10/2020. Median sternotomy was done. With aortic and bicaval cannulations Cardiopulmonary bypass was established.  After pericardiotomy  giant thin-walled  LAAA was identified. The  aneurysm was incised and no thrombus was found inside. After excision  the base of the LAAA was sutured using 5/0 polypropylene . Precaution was taken to avoid the injury of left circumflex coronary artery. No evidence of other cardiac anomalies were identified during the operation. In postoperative ward the patient was uneventful. He was asymptomatic with sinus rhythm in one month postoperative visit. An echocardiography confirmed a normal size of the LA and no evidence of any residual leak or blood clot.

Discussion: Aneurysms may occur in either the left or right atria. or both [2, 3]  It may be associated with other cardiac anomalies, such as tricuspid atresia [4]. Longer than 65 mm is defined as a “giant” LAAA. Usually  aneurysm  arises in the third decade of life. The quickly enlarging aneurysm compresses near by cardiac structures and causes  clinical symptoms. The symptoms includes palpitation, dyspnea, arrhythmia, and thromboembolism. The LAAA arises by dysplastic changes of pectinate muscles and the related bundles of muscles of the LA (6). In Neonates and infants a large aneurysm compresses the pulmonary veins and air way. So they are more likely to develop congestive heart failure and respiratory dystress.  are more likely to develop congestive heart failure and respiratory distress [7, 8]. Transthoracic echocardiography is gold standard for the diagnosis of LAAA, thrombosis or other cardiac anomalies. But transesophageal echocardiography  shows  more detailed evaluation of the structure  of the left atrial appendage [9]. Other imaging techniques, like  CT scan and magnetic resonance imaging (MRI), may be done  for more accurate anatomic definition of the LAAA. Diagnostic criteria for LAAA are (1) origin from an otherwise normal-sized LA; (2) well-defined communication with the LA; (3) location within the pericardium; and (4) distortion of the LV by the aneurysmal body [10]. For the prevention of fatal cardiovascular events , e.g. stroke surgical intervention is recommended though the patient is asymptomatic [11]. Some authors have recommended that asymptomatic patient with LAAA may be managed conservatively some years and frequent follow-up [12-14]. But surgical management is highly recommended in case of a LAAA with serious complications or other coexisting abnormalities. There are no gold standard surgical method options like neck-ligation, purse-string techniques, and stapling, with or without aneurysmal excision [15]. Median sternotomy is usually favorable in situations requiring other surgical procedures, like surgical thrombectomy, the Maze procedure in persistent atrial fibrillation [16], and in mitral regurgitation requiring the valvuloplasty [7]. Otherwise minimal invasive approach may be  an alternative to median sternotomy for LAAA surgery[17, 18]. However, though good surgical outcome, the optimal strategies for the LAAA are still under debate.

Conclusion: Though the LAAA is a rare cardiac anomaly this is associated with fatal complications. The Echocardiography or CT scan are the main tools to diagnose the patient.. In some situations  although medical treatment can be considered, Early surgical management is generally recommended to prevent these complications, even in asymptomatic cases.