A brain dead donor model of porcine orthotopic cardiac transplantation for assessment of cardiac allograft preservation

Background. We aimed to develop a large animal model of orthotopic cardiac transplantation, incorporating donor brain death, to assess new methods of preservation of the donor heart. Methods. Brain death was achieved in the donor pig by inflation of a 20 cc subdural balloon 1 h prior to harvest. The donor heart was stored for 6 h with conventional hypothermic ischaemic preservation. It was then transplanted orthotopically into the recipient pig using the Lower and Shumway technique. One hour after reperfusion, the transplanted heart was weaned from cardiopulmonary bypass with dobutamine support. Dobutamine support was continued for up to 4 h, if required. After 6 h of physiological and biochemical evaluation, the recipient was euthanased and the heart excised for histological assessment. Results. All pigs experienced the classical haemodynamic changes associated with brain death. This resulted in the release of Troponin I, consistent with myocardial injury. The donor operation was successfully completed in 11 out of 13 pigs. Six out of 11 transplanted hearts were successfully weaned from cardiopulmonary bypass, but required ongoing dobutamine support. Conclusions. This porcine model of orthotopic cardiac transplantation is a relevant and practical large animal model for the assessment of new methods of preservation of the donor heart.