LUNG PRESERVATION - THE IMPORTANCE OF ENDOTHELIAL AND ALVEOLAR TYPE-II CELL INTEGRITY

The practice of lung transplantation is constrained by a shortage of s uitable donor organs. Furthermore, even ''optimal'' donor lung grafts are at risk of significant dysfunction perioperatively. Significant in sights into the cellular and molecular mechanisms of pulmonary ischemi a-reperfusion injury have occurred since the publication of previous r eviews on lung preservation 3 to 4 years ago. Recent evidence indicate s that the endothelium plays an essential role in regulating the dynam ic interaction between pulmonary vasodilatation and vasoconstriction a nd is a major target during lung injury. In addition, the composition, function, and metabolism of pulmonary surfactant produced by alveolar type II cells are increasingly being recognized as important factors in pulmonary ischemia-reperfusion injury. We hypothesize that reperfus ion after a period of pulmonary ischemia results in significant endoth elial and alveolar type II cell dysfunction and that an important stra tegy in lung preservation is to preserve the integrity of these cells in the face of this injury. Given the persistent shortage of lungs ava ilable for transplantation, laboratory studies need to focus also on t he ''rescue'' of compromised donor lungs that would have been previous ly regarded as unsuitable. Importantly, innovative work from the labor atory needs to be translated into clinical practice via prospective, r andomized trials to ensure that the prevalence of postoperative lung g raft dysfunction is reduced and the shortage of lung grafts for transp lantation is alleviated.