PATIENTS AND METHODS
After approval from the Human Investigation Committee of the Yale University School of Medicine, we searched the database of the Yale Aortic Institute—containing 3914 patients with thoracic aortic disease– for patients who underwent the ET procedure. We identified 152 patients between 2003–2018 who underwent a Stage I ET procedure by the senior author (JAE). Baseline characteristics were reviewed. In some patients, the elephant trunk of the Stage I procedure was placed for prompt use as the cornerstone of an upcoming Stage II procedure for cogent descending aortic disease. In other patients, the elephant trunk was placed prophylactically for possible late use in case of further descending disease progression (Figure 1). All patients were followed for a median of 52 months (quartile 1–3; 22.7 – 96.5). Data on morbidity and mortality of both Stage I and Stage II procedures were recorded during the follow up period, and long-term mortality was ascertained using the Aortic Institute method described previously [8].