Bridging with solid-organ xenotransplants

Abstract

Patients with acute organ failure often require temporary support. Whereas mechanical assistance has been the only feasible option, growth in the field of xenotransplantation suggests another potential clinical therapy for highly selected patients with acute organ failure who require a bridge to recovery or transplantation. Possible xenogenic viral infection, ethical concerns, and donor availability, however, suggest that pigs, rather than primates, will most likely be the species of choice as potential organ donors. Hyperacute rejection accompanying porcine xenografts is now controllable with a combination of new immunosuppressive strategies and transgenic technology. The first transgenic porcine-to-human organ application will most likely involve extracorporeal perfusion of liver xenografts for fulminant hepatic failure. The first transgenic pig-to-human cardiac xenotransplant will likely involve heterotopically placed porcine cardiac xenografts to bridge patients to allotransplantation or recovery in the setting of cardiomyopathy, acute myocardial infarction, or postcardiotomy shock. Temporary bridging with porcine renal xenografts will be rarely indicated and will not likely be attempted until positive experiences are achieved with other porcine organs.