Heart Transplant and Donors After Circulatory Death: A Clinical-Preclinical Systematic Review

Heart transplant donation after circulatory death: current status and implications

PURPOSE OF REVIEW

The use of cardiac transplantation following circulatory death (DCD) has been limited worldwide. Concerns about cardiac function after warm ischemia and the potential for decreased graft function have been important considerations in this hesitancy. In addition, ethical and legal questions about the two widely used organ procurement methods have led to discussions and public education in many countries.

RECENT FINDINGS

Publication of a US randomized trial of cardiac transplantation following DCD has shown that it is both feasible and has similar short-term outcomes compared with cardiac transplantation following brain death (DBD). These data support those from both Australia and the UK who have largest experience to date.

SUMMARY

The adoption of cardiac transplantation following circulatory death has increased overall cardiac transplantation in those transplant centers who have incorporated these donors. Short term outcomes for DCD organ procurement methods are similar to those outcomes using DBD hearts. Continued study and standardization of warm ischemic times will allow for better comparisons of organ procurement techniques and organ optimization. The ethical concerns about procurement methods, in addition to a discussion of procurement costs and feasibility will need to be addressed further in the efforts to expand the organ pool and increase overall cardiac transplantation numbers.

[Histological and ultrastructural analysis of biopsy specimens of donor heart under conditions of extended period of pharmaco-cold ischaemia]

OBJECTIVE

At the histological and ultramicroscopic level, compare biopsy specimens of donor heart under standard (up to 240 min) and extended (more than 240 min) periods of pharmaco-cold preservation.

MATERIAL AND METHODS

Biopsy specimens of the left atrium of donor hearts: group 1 - 8 samples after transportation with pharmaco-cold preservation of the graft in Bretschneider solution (Dr. Franz Köhler Chemie GmbH, Germany) up to 240 min, (Me 140), and group 2 - 5 samples after an extended pharmaco-cold period (more than 240 min; Me 375) were examined using light microscopy of semi-thin sections and transmission electron microscopy, followed by stereological and statistical analysis.

RESULTS

A comparative study of the myocardium of donor hearts revealed stereotypical dystrophic changes in cardiomyocytes. Semi-thin sections demonstrated a mosaic pattern of myocardial parenchyma in both groups, caused by contracture and less pronounced lytic changes in myocytes, which were accompanied by stromal edema without statistically significant differences according to stereological studies. Ultrathin sections of the perinuclear zones of cardiomyocytes visualized reduction and focal damage to myofibrils and mitochondria in combination with pronounced autophagy; at the same time, with a shorter duration of the pharmaco-cold period, the stereological indicators of cardiomyocyte organelles indicated a relatively better supply of myofibrils with mitochondria.

CONCLUSION

The results obtained suggest a sufficiently high degree of preservation of the tissue and ultrastructural organization of donor hearts with prolonged (more than 240 min) pharmaco-cold ischemia to restore adequate cardiac activity after heart transplantation.