Division of Surgical Transplantation, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX.
Division of Nephrology, Department of Medicine, University of Texas Southwestern Medical Center, Dallas, TX.
Ann Surg. 2020 Sep 1;272(3):397-401. doi: 10.1097/SLA.0000000000004198.
Normothermic machine perfusion (NMP) enables optimized ex-vivo preservation of a donor liver in a normal physiologic state. The impact of this emerging technology on donor liver utilization has yet to be assessed.
NMP of the donor liver and ex-vivo enhancement of its function has been envisioned for decades, however only with recent technological advances have devices been suitable for transition to clinical practice. The present study examines the effect NMP on liver utilization in the United States.
The United Network for Organ Sharing database was queried to identify deceased donor livers procured from 2016 to 2019 (n = 30596). Donor livers were divided by preservation method: standard cold-static preservation (COLD, n = 30,368) versus NMP (n = 228). Donor and recipient risk factors, liver disposition, and discard reasons were analyzed. The primary outcome was liver discard rate between 2 groups.
A total of 4037 livers were discarded. The NMP group had a 3.5% discard rate versus 13.3% in the COLD group (P < 0.001), and this was despite NMP donors being older (47.7 vs 39.5 years, P < 0.0001), more frequently donation after cardiac death (DCD) (18% vs 7%, P < 0.001), and having a greater donor risk index (1.6 vs 1.5, P < 0.05). The most common reasons for liver discard in the COLD group were biopsy findings (38%), DCD warm ischemic time (11%), and prolonged preservation time (10%). Survival analysis, following propensity score matching, found no significant difference in 1-year overall survival between recipients of NMP versus COLD livers.
NMP reduces the discard rate of procured livers despite its use in donors traditionally considered of more marginal quality. NMP maintains excellent graft and patient survival. Broader application of NMP technology holds the potential to generate a significant number of additional liver grafts for transplantation every year, thus greatly reducing the nationwide disparity between supply and demand.
常温机器灌注（NMP）可使供体肝脏在正常生理状态下得到优化的离体保存。这种新兴技术对供体肝脏利用的影响尚未得到评估。
几十年来，人们一直设想对供体肝脏进行 NMP 和离体功能增强，但直到最近技术进步，才有合适的设备过渡到临床实践。本研究检查了 NMP 对美国供体肝脏利用的影响。
利用美国器官共享网络数据库，检索 2016 年至 2019 年期间获取的 30596 例已故供体肝脏。供体肝脏按保存方法分为：标准冷静态保存（COLD，n=30368）与 NMP（n=228）。分析供体和受体的风险因素、肝脏处理和丢弃原因。主要结果是两组之间的肝脏丢弃率。
共有 4037 个肝脏被丢弃。NMP 组的丢弃率为 3.5%，而 COLD 组为 13.3%（P<0.001），尽管 NMP 供体年龄较大（47.7 岁比 39.5 岁，P<0.0001），更频繁地采用心脏死亡后捐献（DCD）（18%比 7%，P<0.001），且供体风险指数更高（1.6 比 1.5，P<0.05）。COLD 组肝脏丢弃的最常见原因是活检结果（38%）、DCD 热缺血时间（11%）和保存时间延长（10%）。在进行倾向评分匹配后的生存分析中，NMP 组与 COLD 组受体的 1 年总生存率无显著差异。
尽管 NMP 用于传统上质量较差的供体，但仍可降低获取肝脏的丢弃率。NMP 可保持良好的移植物和患者存活率。更广泛地应用 NMP 技术有可能每年增加大量额外的肝脏供体用于移植，从而大大减少全国范围内供需之间的差距。
