Abstract:

BACKGROUND: Preservation duration of heart can be breakthrough if the heart was preserved in the beating state with continuous perfusion. However, the traditional explanting and preservation of heart is contrary to preservation with continuous perfusion. It is more scientific to explants and preserves heart with integrity pericardium in the beating state. 
OBJECTIVES: To evaluate feasibility of preservation heart in the beating state and to observe the functional changes of donor heart.
METHODS: Six guangxi bama mini-pigs were selected for this experiment. After pigs were anesthetized with ketamine, a median sternotomy was performed. And then, outside the pericardium, the descending aorta, the left subclavian artery, the superior vena cava, the inferior vena cava and the azygous vein were circumferentially mobilized and encircled with ties. The inferior vena cava was cut at the level of the diaphragm after heparinization. Additional venting was achieved with transection of the right superior pulmonary vein outside pericardium. The aortic cross-clamp was applied at the proximal of the descending aorta and the heart is continuous perfusion with blood through a needle inserted at the left subclavian artery. cardiectomy proceeds as the apex of the heart is elevated cephalad and any remaining intact pulmonary veins were divided. The descending aorta and the left subclavian artery were ligated and transected and the pulmonary arteries were divided distal to bifurcation. Once the explantation was complete, the left ventricle of heart was set with a Foleys (F12) through pulmonary vein and mitral orifice. At last, donor hearts were explanted with integrity pericardium and continuous perfuse in the empty beating state with perfusion apparatus for 4-hour in a sterile container. Four successive time points were set to monitor functional changes of left ventricle, namely, the moment after extraction was T0, 60, 120, 180 and 240 minutes after preservation was T1-T4, respectively. 
RESULTS AND CONCLUSION: Donor hearts excision with integrity pericardium and continuous perfusion preservation in the beating state were successfully performed in all 6 hearts. During preservation, comparison of the maximum ascending rate of left ventricular pressure (dp/dtmax) showed that, dp/dtmax in T0 was higher than other time points, the differences had significance (P < 0.05); but there was no significance between T1 and T2 (P > 0.05). The differences among T1 and T3/T4 had significance (P < 0.05). Comparison of maximum descending rate of left ventricular pressure (-dp/dtmax) showed, T0 was higher than in the other time points (P < 0.05); there was significance among T1, T2, T3 and T4 (P < 0.05). This new method is feasible in donor heart excision and preservation.