Improving the Outcomes of Organs Obtained From Controlled Donation After Circulatory Death Donors Using Abdominal Normothermic Regional Perfusion

Liver Transplantation Today: Where We Are Now and Where We Are Going

Liver transplantation was made a reality through the bravery, innovation, and persistence of Dr. Thomas Starzl. His death in 2017, at the age of 90, makes us pause to consider how far the field has come since its inception by this remarkable pioneer. It also is an opportunity to evaluate the continued novel innovations which contribute to the growth and potential for liver transplantation in the future. The liver transplant community in 2017 continued to be most significantly challenged by an overwhelming disparity between the need for liver transplant and the shortage of donor organs. The many ways in which this critical shortage are being addressed are examined in this article. The continued debate about equitable and efficacious organ allocation, "the liver wars," has dominated much of the recent past, while efforts to optimize current organ availability have also been aggressively pursued. Efforts to optimize the use of marginal and expanded criteria organs have escalated in recent years and have been accompanied by rigorous scientific evaluation. The ongoing opioid epidemic, combined with the approval and availability of highly effective hepatitis C treatment options, has allowed the increased use of HCV positive organs in HCV positive and negative recipients. Machine perfusion, both cold and warm, has moved solidly into the liver transplant world potentiating optimization of marginal donors and also offering potential modulation of liver grafts (ie, gene therapy, stem cell therapy, and defatting). Finally, pharmacological and mechanical interventions in DCD procurement techniques have contributed to improved outcomes in DCD transplants. All of these are explored in this article as a tribute to innovative spirit of Dr. Starzl and his continued impact on liver transplant today.

The Impact of CPR in High-Risk Donation after Circulatory Death Donors and Extended Criteria Donors for Kidney Transplantation

The demand for organs for kidney transplantation (KTX) compels the use of high-risk donation after circulatory death donors (DCDs) and extended criteria donors (ECDs). Many deceased donors receive prehospital CPR, but the literature does not address CPR as a benefit to graft survival. We hypothesized that donor prehospital CPR correlates with improved graft survival with high-risk DCD/ECD kidneys. We retrospectively analyzed KTX recipients and their donor data from 2008 to 2013. A total of 646 cadaveric donors (498 SCDs, 55 DCDs, and 93 ECDs) facilitated 910 KTX. There were 223 KTX performed from 148 high-risk DCDs/ECDs (31 with CPR and 117 without CPR). The mean age of high-risk DCDs/ECDs with CPR was 44.94 versus 53.45 years without CPR (P = 0.005). The recipients of high-risk DCDs/ECDs revealed no significant difference in body mass index, length of stay, discharge Cr, CIT, or DGF with and without CPR. Graft survival at three years was significant with 0/50 failures from high-risk DCDs/ECDs with CPR versus 16/173 without CPR (P = 0.026). Our findings are limited as a single-center retrospective study; however, the result of significant three-year graft survival in high-risk DCDs/ECDs with CPR suggests that prehospital donor CPR should be further investigated for its contribution to the relative quality of the donor.

First Scandinavian Protocol for Controlled Donation After Circulatory Death Using Normothermic Regional Perfusion

Background

Donation after circulatory death (DCD) can increase the pool of available organs for transplantation. This pilot study evaluates the implementation of a controlled DCD (cDCD) protocol using normothermic regional perfusion in Norway.

Methods

Patients aged 16 to 60 years that are in coma with documented devastating brain injury in need of mechanical ventilation, who would most likely attain cardiac arrest within 60 minutes after extubation, were eligible. With the acceptance from the next of kin and their wish for organ donation, life support was withdrawn and cardiac arrest observed. After a 5-minute no-touch period, extracorporeal membrane oxygenation for post mortem regional normothermic regional perfusion was established. Cerebral and cardiac reperfusion was prevented by an aortic occlusion catheter. Measured glomerular filtration rates 1 year postengraftment were compared between cDCD grafts and age-matched grafts donated after brain death (DBD).

Results

Eight cDCD were performed from 2014 to 2015. Circulation ceased median 12 (range, 6-24) minutes after withdrawal of life-sustaining treatment. Fourteen kidneys and 2 livers were retrieved and subsequently transplanted. Functional warm ischemic time was 26 (20-51) minutes. Regional perfusion was applied for 97 minutes (54-106 minutes). Measured glomerular filtration rate 1 year postengraftment was not significantly different between cDCD and donation after brain death organs, 75 (65-76) vs 60 (37-112) mL/min per 1.73 m² (P = 0.23). No complications have been observed in the 2 cDCD livers.

Conclusion

A protocol for cDCD is successfully established in Norway. Excellent transplant outcomes have encouraged us to continue this work addressing the shortage of organs for transplantation.

Heparin but not tissue plasminogen activator improves outcomes in donation after circulatory death liver transplantation in a porcine model

Ischemic-type biliary lesions (ITBLs) arise most frequently after donation after circulatory death (DCD) liver transplantation and result in high morbidity and graft loss. Many DCD grafts are discarded out of fear for this complication. In theory, microvascular thrombi deposited during donor warm ischemia might be implicated in ITBL pathogenesis. Herein, we aim to evaluate the effects of the administration of either heparin or the fibrinolytic drug tissue plasminogen activator (TPA) as means to improve DCD liver graft quality and potentially avoid ITBL. Donor pigs were subjected to 1 hour of cardiac arrest (CA) and divided among 3 groups: no pre-arrest heparinization nor TPA during postmortem regional perfusion; no pre-arrest heparinization but TPA given during regional perfusion; and pre-arrest heparinization but no TPA during regional perfusion. In liver tissue sampled 1 hour after CA, fibrin deposition was not detected, even when heparin was not given prior to arrest. Although it was not useful to prevent microvascular clot formation, pre-arrest heparin did offer cytoprotective effects during CA and beyond, reflected in improved flows during regional perfusion and better biochemical, functional, and histological parameters during posttransplantation follow-up. In conclusion, this study demonstrates the lack of impact of TPA use in porcine DCD liver transplantation and adds to the controversy over whether the use of TPA in human DCD liver transplantation really offers any protective effect. On the other hand, when it is administered prior to CA, heparin does offer anti-inflammatory and other cytoprotective effects that help improve DCD liver graft quality. Liver Transplantation 24 665-676 2018 AASLD.