The experience of extracorporeal membrane oxygenation (ECMO)–supported donors in the field of cardiothoracic transplantation is limited, in contrast to abdominal organs in which ECMO has enhanced and increased the number of available donors.1,2
A 23-year-old healthy male patient was admitted after acute excess 3,4-methylenedioxymethamphetamine consumption. He presented with loss of consciousness, convulsions, and severe hyponatremia. Brain CT showed extensive cerebral edema with transforaminal herniation. The patient developed severe respiratory failure and soon was connected to veno-venous ECMO. First echocardiography revealed severe biventricular dysfunction. Further examination revealed normal left and right ventricular function (Table 1). Seventy-six hours from presentation, the donor was pronounced brain dead, and his organs (lung, kidneys, liver, pancreas, and heart) were procured while on ECMO support. Brain death was confirmed using CT angiography.
The recipient was a 66-year-old man, supported with a HeartMate II left ventricular assist device for 17 months. Early postoperative recovery period was slow, secondary to mechanical lung injury, followed by a consequent rapid recovery. He was discharged on the 23rd postoperative day. Two years of follow-up was uneventful with normal heart function; no evidence for cellular or antibody rejection. Donor specific antibodies were negative; second-year angiography revealed normal coronary arteries with normal hemodynamics.
The remarkable feature of this case is of a patient with marginal function of both heart and lungs who eventually successfully donated these organs by the use of a veno-venous ECMO, as well as his 2 kidneys, pancreas, and liver, benefitting 5 recipients.
Organ-Preserving ECMO: Definition
The use of ECMO support for the primary purpose of preserving organs for transplantation, rather than to save the patient’s life, can be encountered in 3 scenarios; ECMO-supported patients may experience catastrophic brain injury, and after confirmation of brain death, the ongoing use of ECMO may be used for its organ-preserving role. Alternatively, brain-dead potential organ donors may become hemodynamically unstable, endangering the loss of potential donation, and ECMO support may enable safe organ donation. Recently, in some donation after circulatory determination of death (DCD) programs, ECMO is used after death determination.3
What Is the Potential for Organ-Preserving ECMO Donors?
Despite major technological and therapeutic advances, ECMO remains associated with considerable morbidity. Neurological complications are the leading causes of mortality and disability in ECMO patients. However, there are limited data regarding the incidence, pathophysiology, risk factors, and management of neurological injuries, and there are no widely accepted guidelines for their prevention, detection, and management. Among them, brain death is prominent and accounts for 1% to 8%. Yet, data are missing for brain-dead potential donors with hemodynamics instability, and therefore, the numbers are anticipated to be higher.4 For example, it is estimated that DCD donors will increase UK heart transplant activity by 30%.5
Diagnosis of Brain Death on ECMO Support
One of the main problems encountered is the technical challenge of diagnosing brain death in patients on ECMO. Conventional apnea testing is not feasible because oxygenation and carbon dioxide elimination are accomplished by ECMO. There are currently no guidelines, and existing protocols differ.6
Monitoring and Selecting Appropriate Hearts
Beyond the existing criteria for heart donation, more extensive functional evaluation should be performed for the donation of these hearts. These should include cardiac index of 2.5 liters/min/m2 or greater, central venous pressure and pulmonary capillary wedge pressure of 12 mmHg or lesser, and left ventricular ejection fraction of 50% or greater on echocardiography.5 We estimate a time frame of 72 hours for the recovery of the heart; further studies are warranted.
This case suggests that the use of hearts from ECMO-supported donors to left ventricular assist device–assisted patients is feasible and safe and is associated with improved outcomes. Such an approach would potentially expand the donor pool and patient survival.
1. Fan X, Chen Z, Nasralla D, et al. The organ preservation and enhancement of donation success ratio effect of extracorporeal membrane oxygenation in circulatory unstable brain death donor. Clin Transplant
2. Ke HY, Lin CY, Tsai YT, et al. Increase the donor pool: transportation of a patient with fatal head injury supported with extracorporeal membrane oxygenation. J Trauma
3. Dalle Ave AL, Gardiner D, Shaw DM. The ethics of extracorporeal membrane oxygenation in brain-dead potential organ donors. Transpl Int
4. Xie A, Lo P, Yan TD, et al. Neurologic complications of extracorporeal membrane oxygenation: a review. J Cardiothorac Vasc Anesth
5. Messer SJ, Axell RG, Colah S, et al. Functional assessment and transplantation of the donor heart after circulatory death. J Heart Lung Transplant
6. Talahma Murad, Degeorgia Michael. Apnea testing for the determination of brain death in patients supported by extracorporeal membrane oxygenation. J Neurol Res