Endovascular approaches to treat aortic diseases have become an important alternative to open surgical intervention in aortic pathologies. We report a case of an emergency placement of a stent graft in a 16-year-old boy with a contained rupture of an innominate artery pseudoaneurysm. This patient had been previously treated for a mediastinal T-cell lymphoma and underwent mediastinal chemoradiation. He developed tracheal stenosis, requiring multiple tracheal reconstructive surgical procedures, and subsequently emergency ligation of a tracheal-innominate fistula. A pseudoaneurysm of the previously ligated innominate artery developed. Despite coil embolization, it continued to enlarge, requiring emergency endovascular intervention. A pseudoaneurysm of the previously ligated innominate artery subsequently developed, and despite coil embolization, it continued to enlarge, which required emergency endovascular intervention.