Freeman Richard B, Harper Ann M, Edwards Erick B
Department of Surgery, Division of Transplantation, New England Medical Center/Tufts University School of Medicine, Boston, MA 02111, USA.
Liver Transpl. 2002 Aug;8(8):659-66. doi: 10.1053/jlts.2002.34385.
For several years, the Organ Procurement and Transplantation Network/United Network for Organ Sharing (UNOS) Liver and Intestinal Transplantation Committee has been examining effects of changes and proposed changes to the liver allocation system. The Institute of Medicine recently recommended that the size of liver distribution units be increased to improve the organ distribution system. Methods to achieve this and the potential impact on patients and transplant centers of such a change are evaluated in this study. In hypothetical scenarios, we combined geographically contiguous organ procurement organizations (OPOs) in seven different configurations to increase the size of liver distribution units to cover populations greater than 9 million persons. Using the UNOS Liver Allocation Model (ULAM), we examined the effect of 17 different organ allocation sequences in these proposed realignments and compared them with those predicted by ULAM for the current liver distribution system by using the following primary outcome variables: number of primary liver transplantations performed, total number of deaths, and total number of life-years saved. Every proposed new liver distribution unit plan resulted in fewer primary transplantations. Many policies increased the total number of deaths and reduced total life-years saved compared with the current system. Most of the proposed plans reduced interregional variation compared with the current plan, but no one plan consistently reduced variation for all outcome variables, and all reductions in variations were relatively small. All new liver distribution unit plans led to significant shifts in the number of transplantations performed in individual OPOs compared with the current system. The ULAM predicts that changing liver distribution units to larger geographic areas has little positive impact on overall results of liver transplantation in the United States compared with the current plan. Enlarging liver distribution units likely will result in significant shifts in organs across current OPO boundaries, which will have a significant impact on the activity of many transplant centers.
数年来，器官获取与移植网络/器官共享联合网络（UNOS）肝脏及肠道移植委员会一直在研究肝脏分配系统的变化及拟议变化所产生的影响。美国国家医学院最近建议扩大肝脏分配单位的规模，以改善器官分配系统。本研究评估了实现这一目标的方法以及这种变化对患者和移植中心的潜在影响。在假设情景中，我们将七个不同配置的地理上相邻的器官获取组织（OPO）进行合并，以扩大肝脏分配单位的规模，使其覆盖人口超过900万。使用UNOS肝脏分配模型（ULAM），我们在这些拟议的重新调整中研究了17种不同器官分配顺序的效果，并通过以下主要结局变量将其与ULAM对当前肝脏分配系统的预测结果进行比较：进行的初次肝脏移植数量、死亡总数以及挽救的生命年总数。每一项拟议的新肝脏分配单位计划都导致初次移植数量减少。与当前系统相比，许多政策增加了死亡总数并减少了挽救的生命年总数。与当前计划相比，大多数拟议计划减少了区域间差异，但没有一个计划能始终如一地减少所有结局变量的差异，而且差异的所有减少幅度都相对较小。与当前系统相比，所有新的肝脏分配单位计划都导致各个OPO进行的移植数量发生了显著变化。ULAM预测，与当前计划相比，将肝脏分配单位变更为更大的地理区域对美国肝脏移植的总体结果几乎没有积极影响。扩大肝脏分配单位可能会导致器官在当前OPO边界之间发生显著转移，这将对许多移植中心的活动产生重大影响。
