The risk of a second bypass is higher than that of the first surgery and may be combined with complications such as infection, vascular occlusion, pleural effusion, and even cardiac arrest and sudden death. Bypass surgery requires an open chest and cardiac arrest, and if the postoperative care is not adequate, there is a certain chance of delayed healing of the sternum and infection of the wound; it may also be difficult to wake up. A second bypass is generally indicated for people who have an occluded bridge vessel after cardiac bypass surgery, or a blocked coronary artery that is poorly treated with medication and difficult to stent. However, secondary bypass surgery can be made more difficult because of the limited number of bypass sites and vessels available for reoperation; gradual worsening of the condition and poor general status; and the presence of adhesions after the first surgery. It is always recommended to undergo secondary bypass in a regular hospital after evaluation by a physician, and to pay attention to the correct use of medication after the operation.