Protective Effects of a Hydrogen-Rich Preservation Solution in a Canine Lung Transplantation Model.

Background: Molecular hydrogen (H) has protective effects against ischemia-reperfusion injury in various organs. Because they are easier to transport and safer to use than inhaled H, H-rich solutions are suitable for organ preservation. In this study, we examined the protective effects of an H-rich solution for lung preservation in a canine left lung transplantation (LTx) model.

Methods: Ten beagles underwent orthotopic left LTx after 23 hours of cold ischemia followed by reperfusion for 4 hours. Forty-five minutes after reperfusion, the right main pulmonary artery was clamped to evaluate the function of the implanted graft. The beagles were divided into two groups: control group (n = 5), and H group (n = 5). In the control group, the donor lungs were flushed and immersed during cold preservation at 4°C using ET-Kyoto solution, and in the H group, these were flushed and immersed using H-rich ET-Kyoto solution. Physiologic assessments were performed during reperfusion. After reperfusion, the wet-to-dry ratios were determined, and histology examinations were performed.

Results: Significantly higher partial pressure of arterial oxygen and significantly lower partial pressure of carbon dioxide were observed in the H group than in the control group (P = .045 and P < .001, respectively). The wet-to-dry ratio was significantly lower in the H group than in the control group (P = .032). Moreover, in histology examination, less lung injury and fewer apoptotic cells were observed in the H group (P < .001 and P < .001, respectively).

Conclusions: Our results demonstrated that the H-rich preservation solution attenuated ischemia-reperfusion injury in a canine left LTx model.