Protective effects of a hydrogen-rich preservation solution in a canine lung transplantation model

Ann Thorac Surg. 2020 Jul 7;S0003-4975(20)31108-5. doi: 10.1016/j.athoracsur.2020.05.076. Online ahead of print.

Abstract

Background: Molecular hydrogen (H2) has protective effects against ischemia-reperfusion injury in various organs. Because they are easier to transport and safer to use than inhaled H2, H2-rich solutions are suitable for organ preservation. In this study, we examined the protective effects of an H2-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 (CON group, n=5) and hydrogen (H2 group, n=5). In the CON group, the donor lungs were flushed and immersed during cold preservation at 4°C using ET-Kyoto solution, and in the H2 group, these were flushed and immersed using H2-rich ET-Kyoto solution. Physiological assessments were performed during reperfusion. After reperfusion, the wet-to-dry ratios were determined, and histological examinations were performed.

Results: Significantly higher partial pressure of arterial oxygen and significantly lower partial pressure of carbon dioxide were observed in the H2 group than in the CON group (p=0.045 and p<0.001, respectively). The wet-to-dry ratio was significantly lower in the H2 group than in the CON group (p=0.032). Moreover, in histological examination, less lung injury and fewer apoptotic cells were observed in the H2 group (p<0.001 and p<0.001, respectively).

Conclusions: Our results demonstrated that the H2-rich preservation solution attenuated ischemia-reperfusion injury in a canine left LTx model. (247 words).

Keywords: hydrogen-rich solution; ischemia-reperfusion injury; lung transplantation; molecular hydrogen; preservation solution.