Graft Survival and Segment Discards Among Split‐Liver and Reduced‐Size Transplantations in the United States From 2008 to 2018

Abstract

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 splitliver 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], 1.09; 95% confidence interval [CI], 0.82-1.46) or 30-day all-cause graft loss (aHR, 1.13; 95% CI, 0.70-1.80) 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.

Three-Dimensional Liver Model Application for Liver Transplantation

“…It is certainly clearly described in the literature that these issues remain a problem because approximately 8.7% of splitliver segments (52% left lateral segments) and 50% of reduced-size segments (56.4% right lobes and 37.2% right trisegments) were discarded between 2008 and 2018. 31 A major size match issue for infants is the anteroposterior thickness of grafts. 32 Graft size matching and the impact on pediatric LT outcomes and delayed abdominal wound closure have been described elsewhere.…”

“…It is certainly clearly described in the literature that these issues remain a problem because approximately 8.7% of split-liver segments (52% left lateral segments) and 50% of reduced-size segments (56.4% right lobes and 37.2% right trisegments) were discarded between 2008 and 2018. 31…”

Simultaneous split liver/kidney transplantation: A national and single center experience report

“…Moreover, it allows for another way for split livers to be utilized. Discard rates after reduced size transplantation approach 50% and 9% for split‐liver grafts despite similar rates of graft complications between the two with equivalent outcomes for 6,7 . If the usage of split liver grafts increases with this indication, an increase in splitting livers may occur to further increase the donor pool as there is vast underutilization of splitting livers than meet criteria, 5,9,10 despite potentially improving waitlist outcomes with similar mortality outcomes, as seen in the national mandatory split‐liver policy in Italy 11 .…”

“…Moreover, liver grafts that are of adequate quality to be split already preselects for quality liver and concurrent kidney grafts from relatively young healthy donors 5 . Additionally, there remains an unused cohort of organs—those discarded after reduced size or split liver transplants 6,7 …”

“…5 Additionally, there remains an unused cohort of organs-those discarded after reduced size or split liver transplants. 6,7 Nevertheless, despite growing usage of split liver grafts and increasing number of SLK transplants, there has been limited use of the two together-simultaneous split liver and kidney transplants (SSLK). Current practice and outcomes after SSLK are unknown.…”