Physiologic aspects in human lung transplantation

Heart-lung transplantation (HLT), followed by single lung transplantation (SLT) and subsequently bilateral lung transplantation (BLT) have been developed as treatments for patients with end-stage pulmonary diseases. Initially, SLT was limited to idiopathic pulmonary fibrosis (IPF) cases and thought to be contraindicated not only for infectious diseases, but also for non-infectious diseases, including pulmonary emphysema (PE) and primary pulmonary hypertension (PPH), based on physiologic points of view. However, SLT is now widely performed for those non-infectious diseases and most of the recipients return to a normal active life. It is quite possible that BLT is superior to SLT in terms of pulmonary function, and it has been reported that BLT is better for PE and PPH patients in regards to perioperative course, postoperative exercise capacity, and long-term survival. For those situations and because of the present scarcity of donor organs, SLT must be utilized for selected non-infectious diseases for which it is safe and effective. When a single lung is replaced for IPF, PE, and PPH recipients, different physiologic situations are produced postoperatively, the understanding of which is extremely important to achieve good results, not only in the perioperative but also in the long term.