Pediatric Heart Transplantation Following Donation after Circulatory Death, Distant Procurement and Ex-Situ Perfusion

Purpose There remains a significant shortage of organs for children listed for heart transplant. This may be ameliorated by controlled donation after circulatory death (DCD), which has proven success in adults. However, there are numerous challenges in retrieval, assessment and transportation of DCD hearts. We report a unique collaboration between 2 centres, combining expertise in DCD organ retrieval and paediatric transplantation. Methods All families of children over 20 kg listed for heart transplantation were approached for DCD listing; all consented (n = 20). DCD hearts were procured by direct retrieval and perfusion, and then mounted, perfused and assessed on an ex-situ cardiac perfusion machine (Organ Care System (OCS), TransMedics, Inc., Andover, MA), before transfer to the implanting unit. Results Between 1 Feb and 30 Jun 2020, 5 children received a DCD heart (aged 12 to 16 years; two female). Two had previous cardiac surgery, and none had transpulmonary gradient > 8 mmHg. Donor median age was 19.5 years (15-43); three were male. Donor heart mean functional warm ischaemic time was 25 minutes (22 - 28). Mean travel distance was 150 miles (40 - 220) and mean ex-situ perfusion time was 266 minutes (192 - 325). Initial arterial lactate on the OCS was 8.8 mmol/l (4.7-11.7) and venous 8.0 mmol/l (4.7 - 10.1); these fell to 4.7 mmol/l (2.2 - 7.4) and 4.4 mmol/L (2 - 7.1) respectively during transport. No recipients required post-operative mechanical support. Median ITU stay was 8 days (7 - 11) and total hospital stay was 16 days (12 - 21). Pre-discharge echocardiography showed good biventricular function in all recipients except one with mild left and moderate right ventricular dysfunction; all now have excellent graft function. In the same period, 6 DBD transplants were performed in those listed for DCD; although not reaching statistical significance, ventilation, inotrope use, ITU and hospital stay were all shorter in the DCD group. Conclusion The use of previously unavailable DCD hearts has increased transplant activity by 83% in children > 20 kg in this early series. By combining the expertise of one unit in organ retrieval using novel technologies with another in paediatric transplantation, all patients had excellent short-term outcomes. Development of the DCD program to include the use of smaller organs is now a priority for both units.