14.

 This general discussion of the ethics of risk must now be applied to the specific case of xenotransplantation.

First of all, we note that there are issues connected with xenotransplantation, such as the probability of rejection and the increase in the probability of infection because of immunosuppressive therapies, about which some degree of knowledge already exists, although further study is necessary. The data which the scientific community already possesses, together with new data being gathered, can help to establish the threshold of risk that must not be crossed if a transplant operation to be considered morally acceptable.

More complex and uncertain is the assessment and evaluation of risks connected to one specific aspect of xenotransplantation:  the possible transmission to the recipient of infections arising from the xenotransplant (zoonoses) by known or unknown pathogenic agents which are not harmful to the animal but which are possibly dangerous for man. Such infections could escape detection, with the consequent possibility of the spread of the infection to those having close contacts with the patient, leading eventually to its being spread to the entire population.

Since clinical experience of xenotransplantation is quite limited and certainly insufficient to provide reliable statistics on the real probability of occurrences and spread of infections, any decision concerning clinical development of the new therapy can only be based on hypothesis. There is, therefore, an ethical requirement to proceed with the greatest caution.

When the moment for clinical application of xenotransplantation arrives, it will be necessary to select patients carefully, based on clear and well-established criteria,(⁶⁷) and to monitor the patient very closely and constantly. One must also contemplate the possibility of placing the patient in quarantine to prevent the epidemic spread of an infection. Arrangements for some kind of monitoring of those having close contacts with patient should also be made.

Moreover, during the experimental phase of clinical trials, patients should agree not to procreate because of the possible risk of genetic recombination that could affect the patient's germ cells. Sexual abstinence would also be necessary to avoid the venereal transmission of possible viruses.
In the clinical application of xenotransplantation, psychology should also play an important role. It should address the probable repercussions that the recipient could undergo in their psyche (e.g. because of the modification of one's "bodily schema") arising from the acceptance of a foreign organ,(⁶⁸) especially when it comes from an animal.(⁶⁹) In the post-transplant stage, psychology must also provide clinical support the for the patient in the process of integration.