NHLBI workshop summary. Biology of lung preservation for transplantation.

The types of animal models that are used for assessing lung preservation, and the types of interventions that are likely to prove of value, must be carefully selected. For example, the events of warm ischemia are not necessarily the same as those that occur during cold preservation. Warm ischemia has often been used as a means of accelerating the degree of ischemic injury, but the events may not be qualitatively the same. Nonetheless, the use of different types of lung injury models contributes to our overall understanding of mechanisms of lung injury associated with transplantation. Pathologic studies of lung injury ischemia and reperfusion may not prove helpful, as they may be nonspecific and insensitive. To compare results of different preservation methods, a standardized animal model would be most helpful if a universally accepted one could be identified. This would include standard measurements of lung function, standard techniques of transplantation, and follow-up studies of several days' duration after transplantation. Such a model could serve as the ultimate test of preservation methods following its development in a variety of the animal models. It must be emphasized that whereas animal models generally begin with a normal lung that is preserved, the clinical situation differs because the donor lungs may be far from normal at the outset due to the effects of brain death, hemodynamic instability, infection, trauma, and a host of other factors. Thus, the limits of safe preservation in a clinical situation may well be significantly less than the safe preservation time demonstrated in the laboratory.(ABSTRACT TRUNCATED AT 250 WORDS)