Abstract： To the Editor:We report two cases of arch replacement combined with frozen elephant trunk implantation procedure using the collared anastomosis technique for giant arch and thoracic aorta dilatation.A 62-year-old hypertensive female patient was admitted because of endoleak after thoracic endovascular aortic repair (TEVAR).The patient underwent TEVAR procedure because of Stanford type B aortic dissection 5 years ago.The proximal diameter of the stent graft was 50 mm.Another patient was a 52-year-old man suffering from arch and thoracic aneurysm.The diameter of the aneurysm was 52 rmm.