51. Humidified oxygen gas perfusion (persufflation) in organ preservation and cryobanking

Abstract

It is widely recognized that exposure to ischemia and its metabolic and sequelae during procurement and preservation results in tissue injury and/or death and that normothermic reperfusion during transplantation further amplifies the damage. This is also now a recognized issue in organ cryopreservation with data suggesting that inadequately preserved (damaged) organs may not be successfully cryopreserved and rewarmed for transplantation. Published literature reports demonstrate that enhanced oxygenation during organ preservation for kidney, heart, pancreas, and liver, results in improved organ viability, leading to better short and long-term outcomes including limiting chronic rejection in a porcine kidney and heart transplant model. Persufflation (PSF) the flow of hypothermic humidified oxygen gas through the vasculature of organs has been shown to be effective in oxygenating and preserving as well as reconditioning a variety of organs including kidneys, livers, hearts, and pancreata from expanded criteria donors (including Donors after Cardiac Death) in a variety of small and large animal models with excellent outcomes. Persufflation is currently in a clinical trial for reconditioning (after hypothermic static storage) and transplanting livers that would have otherwise been discarded in Europe. PSF also extended significantly the allowable window for organ preservation (for example 14 h instead of 4–6 for the heart and 24 h instead of 8–12 h for the pancreas) without compromising outcomes. However, perhaps due to the unavailability of a “turnkey” portable persufflator and the requirement for use of pressurized oxygen gas cylinders, PSF has not been widely used clinically and has been until recently limited to reconditioning organs after prolonged cold ischemia times (shipped on hypothermic static storage). The development and current availability of a novel portable battery operated electrochemical oxygen generator (“persufflator”) that can be used during flight and deliver humidified oxygen gas to the vasculature of organs may change that. This PSF has been extensively tested with porcine and human pancreata and to a limited extent with porcine kidneys, livers, hearts and composite tissues. It is currently in pilot clinical testing in Canada for pancreas preservation prior to rewarming for digestion and islet purification for clinical islet allo transplantation. In this paper we present we discuss the utility of PSF in organ preservation and in particular organ (re) conditioning prior to cryopreservation as well as during thawing and rewarming prior to transplantation. Financial Support: NIH/NIDDK SBIR R44DK070400.