Mechanical support for acutely failed heart or lung grafts

Heart and lung allograft dysfunction continues to be a problem in thoracic transplantation. Although medical therapy is often sufficient to restore allograft function, occasionally more invasive means are required. Mechanical assist devices, inhaled nitric oxide (iNO), and extracorporeal membrane oxygenation (ECMO) have been used with a modest degree of success in cases of refractory heart, lung, and heart-lung allograft failure. Allograft failure secondary to pulmonary hypertension often responds to iNO concentrations between 5 and 70 ppm without major toxicity. More severe cases may require mechanical assist devices or ECMO and carry higher risks of complications such as bleeding, neurological injury, and death. Utilization of and weaning from these interventions require intensive monitoring. Randomized, prospective studies are not ethically feasible, but case reports and patient series indicate the usefulness of mechanical circulatory support, iNO, and ECMO. This review focuses on the indications, complications, and patient survival rates associated with these modalities.