A Potential Solution to the Shortage of Solid Organs for Transplantation

Abstract

In the United States, the majority of deaths occur unexpectedly, outside hospitals or in emergency departments. 1 Rarely do these deaths provide opportunities for organ donation. In Europe, unexpected deaths provide substantial numbers of transplantable organs through uncontrolled donation after circulatory determination of death (UDCDD). 2 UDCDD considers decedents candidates for donation even when death is unexpected, regardless of location, as long as preservation begins after all life-sustaining efforts have been exhausted.More than 124 000 patients are wait-listed for organs in the United States, a number that increases annually despite attrition from 10 500 who die or become too sick for transplantation. 1 United States policy currently promotes organ recovery from 3 sources; neurologic deaths, controlled circulatory deaths, and live donors for kidneys and partial livers.However, these approaches are incapable of meeting increasing US demand for transplants. During controlled donation after circulatory determination of death (CDCDD), the time from cessation of life support to circulatory arrest often exceeds 60 minutes. Prolonged hypotension leads to irreparable organ damage, thus limiting the effect of CDCDD on organ supply. 3 Live donation primarily affects kidney supply; it is unlikely that altruistic donation will ever meet demand. Although many changes in public policy regarding cadaveric donation are debated (markets and presumed consent), none is likely to become law or make substantial differences in organ supply.The US organ donation system is neglecting the much larger pool of potential donors who could provide organs following unexpected death outside an intensive care unit. In 2006, the US Institute of Medicine projected that implementation of UDCDD protocols nationwide could generate 22 000 more donation opportunities annually in the United States, substantially reducing waiting times for transplantation. 4 If deaths by traumatic causes are added to the Institute of Medicine estimate, the potential donor pool could increase by as much as 63%. 5 UDCDD requires initiation of organ preservation soon after death. If the warm ischemic time, which represents the time organs receive inadequate circulation to sustain cellular function, exceeds an organ-specific threshold, organs are not viable. European programs initiate organ preservation without requiring explicit consent, 2 a concept the US public will not allow despite supporting UDCDD. 6 Therefore, some US programs restricted eligibility to deceased persons who had previously registered for organ donation. However, UDCDD programs in the United States experienced recruit-ment problems by restricting eligibility to previously registered organ donors. 6

Can tissue engineering produce bioartificial organs for transplantation?

“…Moreover, the length of the waiting list continues to increase despite attrition of patients who die or become too sick for transplantation. 46 In the future, tissue engineering technology could be used alleviate this severe shortage by rescuing discarded organs. Proteolysis is known to occur within 4-6 hours after death.…”

Finding a solution to the organ shortage

“…1 In the US and Canada, the overwhelming majority of deaths occur unexpectedly, outside hospital. These deaths are pronounced on the basis of cardiopulmonary death.…”

“…1 The requests to preserve organs for possible donation could be made without actually requesting consent to organ donation. That consent could be made later at a hospital, following usual protocols.…”

“…It is time to consider a strategy that seeks to maximize the pool of potential donors through a twostep process of consent to preserve and donate for those who die outside hospital. 1 Let's begin with the numbers. Spain has the world's highest rate of donation, with 35 per million population; the United States has 26 per million, although some states achieve higher rates, and Canada is at 15 per million, about the same as Australia (International Registry in Organ Donation and Transplantation: www.irodat.org).…”

Successful Transplantation of Lungs From an Uncontrolled Donor After Circulatory Death Preserved In Situ by Alveolar Recruitment Maneuvers and Assessed by Ex Vivo Lung Perfusion

“…If true, this would eventually lead to a lesser number of organs procured, since the numbers of organs procured from DCDD are significantly lower than those procured from DBD (8). Conversely, recovery of organs from uncontrolled DCDD (uDCDD) would increase the pool of organs available for transplantation (9). However, donation from this category adds logistical, ethical, and legal complexity to the donation process in many countries (10).…”