Left ventricular assist device (LVAD) was utilized for the treatment of postcardiotomy heart failure in two patients with Marfan's syndrome. Patient 1 (a 22-year-old) with annuloaortic ectasia (AAE) and DeBakey type II dissection had been supported by LVAD for 87h after composite graft replacement of the ascending aorta and aortic valve. Patient 2 (a 52-year-old) with AAE and DeBakey type I dissection had been supported by LVAD for 91 h after aortic valve replacement. During the assist, both patients complicated bleeding from the fragile left atria near the sites of cannulation. Patient 1 died of multiple organ failure on the 62nd postoperative day, but patient 2 returned to work after surgery.