Hyperbaric Oxygen Therapy in Liver and Kidney Transplantation

Ischemia-reperfusion injury remains a major determinant of early and late graft outcomes after liver and kidney transplantation.Hyperbaric oxygen therapy (HBOT), the delivery of 100% oxygen at pressures above 1 atmosphere absolute (ATA), increases dissolved plasma oxygen independent of hemoglobin and has antioxidant, anti-inflammatory, and mitochondria-protective effects in experimental models.This narrative review summarizes the physical principles and safety of HBOT, the biologic rationale for its use in transplantation, and the preclinical and clinical evidence in liver and kidney recipients.Literature was identified through a structured search of PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, and the Cochrane Library and synthesized qualitatively.Animal models of hepatic and renal ischemia-reperfusion injury consistently show protection, but benefit depends on timing and is greatest when oxygen is delivered during ischemia or as preconditioning, a window that recipient HBOT rarely reaches.Clinical experience is limited to case reports and small series, mostly describing salvage treatment of hepatic artery thrombosis, and no randomized trial of recipient HBOT exists in either organ.Oxygenation of the isolated graft by machine perfusion, by contrast, has entered clinical practice with randomized evidence, and hyperbaric preservation remains experimental.HBOT also has an established adjunctive role in conditions that affect transplant recipients, such as necrotizing soft-tissue infections and compromised wounds.Clinical application to the graft is limited by the mismatch between the protective window and post-transplant delivery, recipient instability, interactions with immunosuppression, chamber access, and the lack of standardized protocols.Recipient HBOT therefore remains biologically plausible but clinically unproven.Its most realistic roles are as a selective salvage therapy for arterial complications, an adjunct for established indications, and a possible complement to ex vivo graft oxygenation, to be tested in prospective studies that define timing, dose, and patient selection.