Background:Aorta dilatation at the root surface of the aorta can have a variety of causes. Many congenital or acquired conditions can lead to weakness of the aortic wall. Ascending aortic dilatation is rare in childhood and is often associated with forms of connective tissue disease or predisposing cardiac malformations, especially bicuspid aortic valve disease. Case Presentation:Herein, we present the case of a six-month-old boy with severe dilation of the ascending aorta. The patient was referred to the doctor by the parents because of persistent cough. After several examinations, the infant's heart disorder was noted, and he was referred to Shahid Rajaie Heart Center. After performing echocardiography, severe dilatation of the ascending aorta was diagnosed.He was transferred to the operation room. Total thymectomy was performed, and then resection and repair of the ascending aorta and arch of the aorta was done. After ventilating the cardiac cavities, the aortic clamp was removed, and the patient's heart found a rhythm as it warmed up. After hemostasis and placement of the chest tube drain and installation of a temporary pacemaker wire, the patient's sternum was closed, and he was transferred to the ICU. After 2 days, the patient was transferred from the ICU to the ward in good condition and then discharged from the hospital without any problems. Conclusions:Aortic dilation is a rare disease in children. The sign and symptoms may be different in any patient, and complete diagnostic tests must be performed before performing the procedure.

Aortic root, Aortic insufficiency, Aneurysm aorta,Dilation of aorta