A 69-year-old man was presented with a holosystolic and early diastolic murmur in cardiac auscultation, pretibial edema and elevated inflammation markers. Aortic valve and ascending aorta had been replaced 9 months earlier. Transesophageal echocardiography revealed massive eccentric regurgitation and dehiscence of the aortic valve, resulting in a giant circular false aneurysm with connection to the lumen of the aortic arch. CT and MR confirmed extensive leakage in a covered perforation. The false lumen was confined by a newly formed vessel wall, since the native Aorta ascendens had been excised. Smooth muscle cells expressing the progenitor marker CD34 were detected selectively in this region, indicating a contribution of circulating progenitor cells to the false vessel wall. After detection of Staphylococcus epidermidis in blood, another urgent Bentall operation was performed. However, the patient succumbed to right ventricular failure and multiple organ failure on postoperative day 1.