The operation is performed in a by-pass operation of the heart without stopping the heart, ie, without connecting to the heart-lung pump. This surgery is performed at an advanced age, with impaired pulmonary function, patients with impaired renal function, patients with low cardiac performance due to heart attack, and patients with a risk of stroke. By continuing to work the heart with special devices, the obstructed vein area is still still brought in, and by-pass is made with the new vein prepared from the forehead, chest vein or arm vein in advance. This is one of the advantages of having a hospital stay during the surgery and less blood being used in the surgery.