Retrograde perfusion of the false lumen in cases of type I dissection of the thoracic aorta may not permit reperfusion of the coronary arteries when the aortic cross-clamp is removed. We have employed a Y connector between the coronary perfusion outlet of the oxygenator and cardioplegia delivery system. This allows reperfusion of the coronary arteries through the ascending aortic graft. As cardiopulmonary bypass is discontinued, the true aortic lumen is reexpanded and the false lumen collapsed by forward flow of blood from the heart. The successful use of this system is described.