The purpose of this study is to evaluate the safety and efficacy of endovascular repair, using the Thoracic EXCLUDER Endoprosthesis, when used in the treatment of descending thoracic aortic disease as indicated by radiological testing at time of discharge, and 1, 6, 12 months and annually following implantation, and to determine the proportion of patients who experience adverse events during and after the implantation procedure, including disease-specific and overall mortality rates.