Intraoperative High Fraction of Inspiratory Oxygen is Independently Associated with Worse Outcome After Living-Donor Liver Transplantation: A Retrospective Study.

BACKGROUND: Ischemia and reperfusion injury is an important factor that determines graft function after liver transplantation, and oxygen plays a crucial role in this process. However, the relationship between the intraoperative high fraction of inspiratory oxygen (FiO2) and living-donor-liver-transplantation (LDLT) outcome remains unclear. PATIENTS AND METHODS: A total of 199 primary adult-to-adult LDLT cases in Kyoto University Hospital between January 2010 and December 2017 were enrolled in this study. The intraoperative FiO2 was averaged using the total amount of intraoperative oxygen and air and defined as the calculated FiO2 (cFiO2). The cutoff value of cFiO2 was set at 0.5. RESULTS: Between the cFiO2 <0.5 (n = 156) and ≥0.5 group (n = 43), preoperative recipients' background, donor factors, and intraoperative parameters were almost comparable. Postoperatively, the cFiO2 ≥0.5 group showed a higher early allograft dysfunction (EAD) rate (P = 0.049) and worse overall graft survival (P = 0.036) than the cFiO2 <0.5 group. Although the cFiO2 ≥0.5 was not an independent risk factor for EAD in multivariable analysis (OR 2.038, 95%CI 0.992-4.186, P = 0.053), it was an independent risk factor for overall graft survival after LDLT (HR 1.897, 95%CI 1.007-3.432, P = 0.048). CONCLUSION: The results of this study suggest that intraoperative high FiO2 may be associated with worse graft survival after LDLT. Avoiding higher intraoperative FiO2 may be beneficial for LDLT recipients.