Untreated thoracic aneurysms can be life-threatening. As many as 78% of untreated patients with TAA die within 5 years after diagnosis, most often from rupture of the aneurysm. Conventional surgical treatment, either tube graft placement or patch aortoplasty, is a high risk surgical procedure. Repair of the thoracic descending aorta is performed with a thoracotomy and cross-clamping of the aorta, with or without a shunt by-pass to maintain distal perfusion.