A Trip to the Moon: Neonatal ABO Non-Compatible Heart Transplant in Donor Circulatory Death
Donation after Circulatory Death (DCD) is gaining worldwide acceptance as an adjunct to brain death (BD) in transplant surgery. Initially performed for abdominal organs procurement, DCD was then carried out for heart and lung transplants (HT). Most DCD-HT protocols regard their first cases to be performed with both donor and recipient located in the same institution. The first three cases were performed in Denver (Colorado, USA) in 2008 (ultra-fast procurement, without in situ graft evaluation), and since then few records of children have been published. Several ways of harvesting, including ultra-fast, normothermic regional perfusion -NRP- or on peripheral Extra Corporeal Membrane Oxygenation (ECMO) and preservation during transport (cold storage -CS-, Transmedics Organ Care System -OCS-) allow different combinations possible, as displayed by groups in Australia, Belgium, Great Britain and other countries.
Our Institution was offered a heart from a 3 day-old, 3.4 Kg child, blood group A, suffering irreversible encephalopathy as a result of neonatal asphyxia. Parents accepted withdrawal of life-sustaining therapy (WLST) and agreed to donation. The donor Hospital was located 340 km away. Concomitantly, a two month-old, 3.1 kg, blood group type B and with non-compaction ventricles was awaiting HT in our neonatal unit. Thus, we envisioned a great opportunity and considered a distant procurement of an ABO non-compatible DCD-HT.
The local transplant coordinator run the DCD protocol while the surgeons kept waiting. Seventeen minutes after WLST, mean blood pressure dropped below 30 mmHg. Twenty minutes later, the heart arrested. Once permission was granted (five minutes afterwards) a fast sternotomy was performed. The supra aortic vessels were clamped altogether. Single purse-string sutures in the aorta and right appendage were placed, both cannulae inserted, fastened, and connected to ECC lines. Time since skin incision to ECC establishment was 7 minutes. Functional warm ischemia was 32 minutes (20+5+7), whilst overall warm ischemia lasted for 49 (17+20+5+7) minutes.
Next step was a cut-down in the innominate artery above the clamp. The heart resumed spontaneous rhythm in less than one minute. Ventilation was restored and ECC was maintained for 32 minutes. ECC was weaned and the heart was assessed for 10 minutes. An epicardial echo showed proper contractility. Upon cardioplegic arrest (500 ml HTK-Custodiol; Koehler Chemi, Alsbach-Haenlien, Germany), the graft was harvested as routinely. After retrieval, the heart was cold stored (CS) and transported by plane to our Hospital.
An orthotopic bi-caval transplant was performed. Isohemaglutinin titers proved negative in all four samples withdrawn in our ABO non-compatible protocol. Sinus rhythm resumed spontaneously after aortic clamp removal. Trans-esophageal ecocardiography showed good biventricular function. Overall cold ischemia (since aortic donor clamp until recipient clamp removal) was 245 minutes. Ten weeks later, the child was discharged home in good condition.
To our knowledge, this might be the first combined ABO non-compatible plus neonatal DCD-HT case in the world.
Provided the limitations of a single case, several conclusions can be drawn from this report:
1. Given the lack of brain-death donors, DCD could increase the pool in neonates.
2. Fast sternotomy and ECC rescue proves successful for procurement in neonates.
3. Distant procurement plus cold storage for DCD donors is feasible, sparing OCS.
4. DCD-HT and ABO non-compatible strategies are complementary to each other.
References
1. Boucek MM, Mashburn C, Dunn SM et al. Pediatric heart transplantation after declaration of cardiocirculatory death. N Engl J Med 2008;359:709-14
2. Dhital KK, Iyer A, Connellan M et al. Adult heart transplantation with distant procurement and ex-vivo preservation of donor hearts after circulatory death: a case series. Lancet 2015;385:2585-91
3. Messer S, Page A, Colah S et al. Human heart transplantation from donation after circulatory-determined death donors using normothermic regional perfusion and cold storage. J Heart Lung Transplant 2018;37:865-9
4. Tchana-Sato V, Ledoux D, Detry O et al. Successful clinical transplantation of hearts donated after circulatory death using normothermic regional perfusion. J Heart Lung Transplant 2019;38:593-8
5. Urschell S, West LJ. ABO-incompatible heart transplantation. Curr Opin Pediatr 2016;28(5):613-9