A 14-year-old boy who underwent aortic valve-sparing operation for annuloaortic ectasia at the age of 9 was referred to our service with a diagnosis of acute type A aortic dissection. Emergency total arch replacement with the elephant trunk technique was done successfully and the postoperative course was uneventful. However, computed tomography (CT) 2 weeks after the operation showed a new dissection and enlargement in left subclavian artery and folded elephant trunk. Dilatation in coronary buttons were also seen since the time of surgery. No residual dissection was found in the aorta. Careful follow up is necessary for this case due to multiple aneurysmal changes and a new dissection lesion in a short period. Loeys-Dietz syndrome (LDS) is characterized by vascular findings (aortic aneurysm and dissection) and skeletal manifestations. Due to aortic dissection occurring in smaller diameter aortas in LDS patients than in Marfan syndrome, early and aggressive surgery is recommended for patients with LDS.