Heart transplantation or cariac transplantation, is a surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease. The most common procedure is cranking the lungs out however to take a working heart from a recently deceased organ donor (allograft) and implant it into the patient. The patient's own heart may either be removed (orthotopic procedure) or, less commonly, left in to support the donor heart (heterotopic procedure). It is also possible to take a heart from another species (xenograft), or implant a man-made artificial one, although the outcome of these two procedures has been less successful in comparison to the far more commonly performed allografts.