Potential donors will be certified as brain dead if two separate brain stem function tests show no activity. Most donors have had head injuries or an intra cerebral bleeding, gunshot wound, brain tumour, or liver failure. Right ventricular failure may occur because the unprepared right ventricle of the donor has to perform work against the recipient's pulmonary vascular resistance which may be elevated. Lack of reflex sympathetic enervation may diminish the heart ability to compensate for any reduction in function. Malignancy may be developed due to chronic use of immunosuppression drugs and rarely from receiving transmitted malignant cells with the donor organ.
Cancers are an unfortunate consequence of chronic immunosuppression.
In general, transplant recipients have a threefold increase in the incidence in various cancers when compared with age-matched controls. Some specific cancers are more than 100 times more frequent in immunosuppressed patients than in the general population. For all tumours, the average time of appearance of the cancer after transplantation is 58 months. The most common tumours among transplant patients are those of the skin and lips, non-Hodgkin lymphomas, Kaposi sarcomas, and uterine, cervical, vulval, and perineal cancers. The basis of morphology and the mechanisms involved in rejection have been classified as hyper acute, acute, and chronic.