Brain-Dead People: Exploring Ethical Implications

In a recent article published in the journal Science, the authors propose using the bodies of people declared neurologically deceased (brain-dead) for research purposes. Physiologically maintained deceased (PMD) individuals mimic living human physiology and could provide new research opportunities.

These types of trials have been conducted previously, such as the case of a genetically modified pig liver transplant in China to a brain-dead recipient. During the ten days that lasted the experiment, the porcine liver produced bile and albumin.

Previously, in the first trial of its kind, a pig kidney was transplanted into a brain-dead woman in September 2021, and the organ functioned properly for 54 hours.

Bioethical assessment

These types of experimental procedures merit multiple bioethical considerations. In addition to those relating to the use of animal organs in humans, we must also consider the use of brain-dead patients as a field of research.

First, in all cases, it must be confirmed that the patient died by neurological criteria, that is, by global brain death. All brain functions, both cerebral and brainstem, must have ceased.

A diagnosis of death is an essential requirement for all organ donations for transplant from a deceased donor, thus avoiding the removal of organs from patients who may not be dead. This could occur when the diagnosis of death is based on insufficient time in cardiorespiratory arrest.

Furthermore, in the case of clinical experimentation on the bodies of brain-dead individuals, their death must be independent of the subsequent use of their bodies for clinical experimentation. This is similar to the requirement for compliance with the Dead Donor Rule, which establishes that the death of a person must be independent of organ donation.

Secondly, priority should be given to using the organs of brain-dead patients for transplantation into patients who need them, rather than conducting experiments as described above. A fair assessment of healthcare priorities seems essential given the shortage of organs for transplantation.

Third, with express consent, all adults may donate their bodies for teaching or research purposes, regardless of age or health status, unless they suffer from a serious infectious disease at the time of death. Similarly, the case of experimentation on brain-dead patients in whom some vital functions are artificially maintained does not appear to be any different from a bioethical perspective.

Although in Spain it is not legally necessary to express the desire to donate organs after death to become a donor, it is necessary to do so in order to donate a body for the aforementioned purposes.

Fourth, in the case of organ donation, the benefit obtained is objective, since patients with severe organ dysfunction can continue to live in good condition after receiving an organ if the process is successful. However, the usefulness of the tests proposed by the authors mentioned above is still very limited.

In the clinical experiments described, the viability of the bodies whose circulatory and respiratory functions are artificially maintained does not allow the tests on them to be maintained long enough to confirm reliable results.

On the other hand, the level of clinical translation of experimental models with brain-dead patients should be considered.

Finally, if the use of PMDs improves the feasibility of the proposed model, it could prove useful as an intermediate step between animal and human experiments. Bringing scientific trials closer to the human context would allow for more representative results in gene editing experiments.