Thoracic organ preservation

Abstract

Clinical heart transplantation began in December 1967 when Cristiaan Barnard performed the first human to human heart transplant on a 57 year old man with ischaemic heart disease, in Cape Town. This ushered in a bout of enthusiastic heart transplantations world-wide over the subsequent few years which soon waned as the problems of acute rejection and infection became apparent to those who had embarked on this venture without fully understanding the complications. The importance of a well functioning donor heart cannot be overemphasized. Early donor heart failure accounts for approximately 26% of the deaths of heart transplant recipients today and there is also a steep rise in acute mortality associated with storage times in excess of two hours (9.8% < 2 hours rising to 17.6% > 4 hours), although satisfactory function has been reported in a few hearts stored for up to 6 hours.1 Careful selection and meticulous management of the donor, followed by optimal storage, are therefore essential to a satisfactory outcome.2 There is evidence that some of the problems of organ preservation are related to metabolic changes in the donor consequent upon brain death3-6 and recent ongoing studies by our own group show some benefit from hormone replacement therapy in the donor.7 There are essentially two major approaches to the problem of organ storage; metabolic inhibition resulting in reduced substrate requirements, and the supply of metabolic requirements, or a combination of both. Although nonperfusion methods currently predominate, the simplicity of these methods are overshadowed by the short safe time interval which they allow and the variable functional quality which results. The author believes that perfusion preservation methods will predominate in the future and may also allow expansion of the donor pool bywhole donor and/or ex vivo thoracic organ resuscitation.