Reasons for not using organs
Before considering patterns of organ retrieval in more detail, it is useful to consider the challenges involved with organ retrieval and possible reasons why organs are not used. These reasons can be grouped under four main categories: medical, non-medical, other uses and unknown. ‘Medical’ refers to any medical condition or situation that prevents the organ from being used, such as injury, disease or lack of suitable compatibility. It is by far the most common reason for non-use, accounting for approximately 68% of cases. ‘Other’ refers to uses other than transplant, such as recovery of tissues (e.g. heart valves) or research (5%). Of special interest is the group of non-medical reasons (12%), such as lack of suitable facilities, lack of consent, or problems in reaching potential recipients. For these cases, it may be possible to change existing retrieval practices so that fewer organs are left unused. This, in fact, is what appears to be happening. In Figure 1, the four categories of non-use are plotted for years 1991 to 2004. A least-squares regression line is plotted for each set of points in order to highlight the overall trend. On average, the non-medical reasons are trending downward, an encouraging sign that suggests that there have indeed been improvements in the retrieval, allocation, and transplantation of organs.