To date, endovascular repair of thoracic dissections is a reality, associated with acceptable morbidity and mortality. We present the case of a 72-year-old woman presenting a retrograde aortic dissection at the postoperative day 12, after an endovascular repair for a 60-mm thoracic dissecting aneurysm. Two years earlier, she had presented an uncomplicated thoracoabdominal type B aortic dissection between the isthmic aorta and the iliac bifurcation. Despite an acceptable blood pressure control, a 62-mm thoracic dissecting aneurysm was observed on the 24-month CT-scan. Due to a chronic obstructive pulmonary disease, we chose the endovascular approach to exclude the thoracic entry tear leading to the complete false lumen thrombosis around the endoprosthesis. However, the inferior part of the false lumen remained patent due to a second abdominal entry tear. The initial outcome was uneventful but the patient presented a sudden death syndrome twelve days after the endovascular repair. During the autopsy, we discovered an intrapericardial rupture of a retrograde dissection, starting at the level of the proximal bare spring of the endoprosthesis. We discuss some important technical details to improve the safety, and to reduce the risk of immediate or delayed complications.