Effect of Hyperbaric Oxygen on Hypoxic-ischemic Damage in Cold Preserved Tissues

Abstract

Objective: To assess the possible effect of hyperbaric oxygen (HBO) in preventing hypoxic-ischemic damage in cold-preserved organs. Methods: Visceral organs of white male New Zealand rabbits (n=6) were removed and examined in two groups: right kidneys (n=6), right lungs (n=6), right lobe of livers (n=6) and the hearts of three animals constituted the HBO group and left kidneys (n=6), left lungs (n=6), left lobe of livers (n=6) and the hearts of the remaining animals (n=3) formed the control group. After excision, organs in the HBO group were immediately placed in 100% oxygen at 2.5 atmosphere absolute for 2 h while those in the control group were kept in room air during this period. All tissues were kept in University of Wisconsin (UW) solution, 4 °C, at the end of the experiment. Tissue sections were obtained at 2 h after removal (T1, early stage) and at 125% of the maximal acceptable ischemic time determined for each tissue (T2, late stage). Histopathological evaluation was made by blinded pathologists using semiquantitative scoring systems and scores were compared between the HBO and control groups. Results: Tissue injury in the lungs and kidneys of the HBO group was milder compared to controls at both the early and late stages, but the difference was not statistically significant. Heart tissue in both the HBO and control groups demonstrated signs of ischemic injury at T2, while liver tissue did not change significantly from T1 to T2. Conclusion: These preliminary results suggest that further studies with larger sample sizes, particularly involving lung and kidney tissue and conditions applicable to clinical settings, are needed to determine any effect of HBO during cold storage.

Keywords

• hyperbaric oxygen therapy
• cold preservation
• solid organ
• transplantation
• transportation