A 40-year-old man underwent ascending aortic replacement for acute type A aortic dissection. Eight years later, Bentall procedure and total arch replacement with an open stentgraft (OSG) were performed due to enlargement of the aortic root and distal arch dissection as well as exacerbation of aortic valve incompetence. The computed tomography(CT) taken at 22 months postoperatively showed better stentgraft expansion than that immediately after the operation, reduction in the diameter of the distal aortic arch, and thrombosis of the false lumen from the aortic arch to the entire descending aorta. However, the CT taken at 33 months postoperatively revealed a new entry to the distal end of the stentgraft and blood flow in the false lumen. Although OSG is useful for extensive aortic aneurysm, strict follow-up is necessary in OSG for aortic dissection.