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

Hidenao Kayawake , Toyofumi F Chen-Yoshikawa , Masao Saito , Hiroya Yamagishi , Akihiko Yoshizawa, Shin-Ich Hirano , Ryosuke Kurokawa , Hiroshi Date Ann Thorac Surg . 2021 Jan;111(1):246-252. doi: 10.1016/j.athoracsur.2020.05.076. Epub 2020 Jul 8. PMID: 32649946

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 group (n = 5), and H2 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 H2 group, these were flushed and immersed using H2-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 H2 group than in the control group (P = .045 and P < .001, respectively). The wet-to-dry ratio was significantly lower in the H2 group than in the control group (P = .032). Moreover, in histology examination, less lung injury and fewer apoptotic cells were observed in the H2 group (P < .001 and P < .001, respectively).

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