Split-liver transplantation has allocation advantages over reduced-size transplantation because of its ability to benefit 2 recipients. However, prioritization of split-liver transplantation relies on the following 3 major assumptions that have never been tested in the United States: similar long-term transplant recipient outcomes, lower incidence of segment discard among split-liver procurements, and discard of segments among reduced-size procurements that would be otherwise “transplantable.” We used United Network for Organ Sharing Standard Transplant Analysis and Research data to identify all split-liver (n = 1831) and reduced-size (n = 578) transplantation episodes in the United States between 2008 and 2018. Multivariable Cox proportional hazards modeling was used to compare 7-year all-cause graft loss between cohorts. Secondary analyses included etiology of 30-day all-cause graft loss events as well as the incidence and anatomy of discarded segments. We found no difference in 7-year all-cause graft loss (adjusted hazard ratio [aHR], 1.1; 95% confidence interval [CI], 0.8-1.5) or 30-day all-cause graft loss (aHR, 1.1; 95% CI, 0.7-1.8) between split-liver and reduced-size cohorts. Vascular thrombosis was the most common etiology of 30-day all-cause graft loss for both cohorts (56.4% versus 61.8% of 30-day graft losses; P = 0.85). Finally, reduced-size transplantation was associated with a significantly higher incidence of segment discard (50.0% versus 8.7%) that were overwhelmingly right-sided liver segments (93.6% versus 30.3%). Our results support the prioritization of split-liver over reduced-size transplantation whenever technically feasible.

中文翻译：

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2008 年至 2018 年美国肝分裂和缩小移植中的移植物存活率和片段丢弃率

分裂式肝移植比缩小体积移植具有分配优势，因为它能够使 2 位受者受益。然而，分裂肝移植的优先次序取决于以下 3 个从未在美国测试过的主要假设：相似的长期移植受者结果、分裂肝采购中肝段丢弃率较低以及减少的肝段丢弃率- 在其他情况下“可移植”的规模采购。我们使用 United Network for Organ Sharing Standard Transplant Analysis and Research 数据来确定 2008 年至 2018 年间美国所有的分裂肝 (n = 1831) 和缩小体积 (n = 578) 移植事件。多变量 Cox 比例风险模型是用于比较队列之间的 7 年全因移植物丢失。二次分析包括 30 天全因移植物丢失事件的病因学以及丢弃节段的发生率和解剖结构。我们发现 7 年全因移植物丢失（调整后风险比 [aHR]，1.1；95% 置信区间 [CI]，0.8-1.5）或 30 天全因移植物丢失（aHR，1.1；95 % CI, 0.7-1.8) 在分裂肝脏和缩小队列之间。血管血栓形成是两个队列中 30 天全因移植物丢失的最常见病因（占 30 天移植物丢失的 56.4% 和 61.8%；P  = 0.85）。最后，缩小尺寸移植与显着更高的肝段丢弃率（50.0% 对 8.7%）相关，其中绝大部分是右侧肝段（93.6% 对 30.3%）。我们的结果支持在技术可行的情况下优先考虑分割肝脏而不是缩小尺寸移植。