Division of Transplant Surgery, Department of Surgery, University of Washington, Seattle.
Clinical and Bio-Analytics Transplant Laboratory (CBATL), University of Washington, Seattle.
JAMA Surg. 2023 Jun 1;158(6):610-616. doi: 10.1001/jamasurg.2023.0191.
Small waitlist candidates are significantly less likely than larger candidates to receive a liver transplant.
To investigate the magnitude of the size disparity and test potential policy solutions.
DESIGN, SETTING, AND PARTICIPANTS: A decision analytical model was generated to match liver transplant donors to waitlist candidates based on predefined body surface area (BSA) ratio limits (donor BSA divided by recipient BSA). Participants included adult deceased liver transplant donors and waitlist candidates in the Organ Procurement and Transplantation Network database from June 18, 2013, to March 20, 2020. Data were analyzed from January 2021 to September 2021.
Candidates were categorized into 6 groups according to BSA from smallest (group 1) to largest (group 6). Waitlist outcomes were examined. A match run was created for each donor under the current acuity circle liver allocation policy, and the proportion of candidates eligible for a liver based on BSA ratio was calculated. Novel allocation models were then tested.
Time on the waitlist, assigned Model for End-Stage Liver Disease (MELD) score, and proportion of patients undergoing a transplant were compared by BSA group. Modeling under the current allocation policies was used to determine baseline access to transplant by group. Simulation of novel allocation policies was performed to examine change in access.
There were 41 341 donors (24 842 [60.1%] male and 16 499 [39.9%] female) and 84 201 waitlist candidates (53 724 [63.8%] male and 30 477 [36.2%] female) in the study. The median age of the donors was 42 years (IQR, 28-55) and waitlist candidates, 57 years (IQR, 50-63). Females were overrepresented in the 2 smallest BSA groups (7100 [84.0%] and 7922 [61.1%] in groups 1 and 2, respectively). For each increase in group number, waitlist time decreased (234 days [IQR, 48-700] for group 1 vs 179 days [IQR, 26-503] for group 6; P < .001) and the proportion of the group undergoing transplant likewise improved (3890 [46%] in group 1 vs 4932 [57%] in group 6; P < .001). The smallest 2 groups of candidates were disadvantaged under the current acuity circle allocation model, with 37% and 7.4% fewer livers allocated relative to their proportional representation on the waitlist. Allocation of the smallest 10% of donors (by BSA) to the smallest 15% of candidates overcame this disparity, as did performing split liver transplants.
In this study, liver waitlist candidates with the smallest BSAs had a disadvantage due to size. Prioritizing allocation of smaller liver donors to smaller candidates may help overcome this disparity.
与较大的候选者相比，较小的候补者获得肝移植的可能性显著降低。
调查大小差异的幅度，并检验潜在的政策解决方案。
设计、地点和参与者：根据预先设定的体表面积（BSA）比值限制（供体 BSA 除以受体 BSA），生成了一个决策分析模型，以便根据体表面积（BSA）将肝移植供体与候补者进行匹配。参与者包括来自器官获取和移植网络数据库的成年死亡肝移植供体和候补者，时间为 2013 年 6 月 18 日至 2020 年 3 月 20 日。数据分析于 2021 年 1 月至 2021 年 9 月进行。
根据 BSA 从最小（第 1 组）到最大（第 6 组）将候选者分为 6 组。检查候补名单的结果。为当前急性圆肝分配政策下的每位供体创建了一次匹配运行，并计算了根据 BSA 比值有资格进行肝脏移植的候选者的比例。然后测试了新的分配模型。
通过 BSA 组比较候补名单上的等待时间、分配的终末期肝病模型（MELD）评分和接受移植的患者比例。使用当前分配政策进行建模，以确定按组获得移植的基线。模拟新的分配政策，以检查访问权限的变化。
该研究共纳入 41341 名供体（24842 名男性[60.1%]和 16499 名女性[39.9%]）和 84201 名候补者（53724 名男性[63.8%]和 30477 名女性[36.2%]）。供体的中位年龄为 42 岁（IQR，28-55），候补者的中位年龄为 57 岁（IQR，50-63）。女性在 2 个最小 BSA 组中占比过高（分别为第 1 组的 7100 名[84.0%]和第 2 组的 7922 名[61.1%]）。每组人数增加，候补时间减少（第 1 组为 234 天[IQR，48-700]，第 6 组为 179 天[IQR，26-503]；P < .001），接受移植的比例也相应提高（第 1 组为 3890 名[46%]，第 6 组为 4932 名[57%]；P < .001）。当前急性圆肝分配模型对候选者中最小的 2 个组不利，分配给候补名单上的比例相对应的肝脏数量减少了 37%和 7.4%。将最小的 10%的供体（按 BSA）分配给最小的 15%的候选者，可以克服这种差异，进行劈离式肝移植也可以。
在这项研究中，BSA 最小的肝候补者由于体型而处于不利地位。优先将较小的肝供体分配给较小的候选者可能有助于克服这种差异。
