Split liver transplantation is utilized infrequently and concentrated at few transplant centers in the United States

Expanding the Liver Donor Pool: Promise and Peril

Liver transplantation remains a life-saving therapy for a growing list of indications. Although 10,660 adult liver transplants were performed in the United States in 2023, a 50% increase over the preceding decade, the demand continues to far exceed the supply. Efforts to expand the liver donor pool by using donors that were previously considered unsuitable have remained an important strategy to help overcome shortages. We discuss the progress that has been made over the past decade, as well as potential future barriers that will need to be overcome to help successfully expand the liver donor pool.

Expanding pediatric liver transplants: the role of split grafts, allocation policies, and machine perfusion

PURPOSE OF REVIEW

Pediatric liver transplant waitlist mortality remains disproportionately high, particularly among infants under one year old. Despite the success of split liver transplantation (SLT) in improving pediatric access to transplants, its utilization remains limited. This review examines barriers to SLT adoption, explores the impact of pediatric-focused allocation policies, and evaluates the potential of machine perfusion technology in expanding the pediatric donor pool.

RECENT FINDINGS

Studies have demonstrated that SLT outcomes are comparable to whole graft transplants when performed at experienced centers. However, logistical challenges, technical expertise, and policy limitations hinder its widespread adoption. Countries with pediatric-prioritized allocation and mandatory SLT policies, such as Italy and the United Kingdom, have significantly reduced pediatric waitlist mortality. Additionally, machine perfusion technology has emerged as a promising solution, allowing for ex vivo graft splitting and reducing ischemic injury, which may enhance graft utilization.

SUMMARY

A multifaceted approach is necessary to improve pediatric liver transplant outcomes, including stronger pediatric-first allocation policies, SLT training expansion, and integration of machine perfusion technologies. Implementing these strategies in the United States could significantly reduce pediatric waitlist mortality without negatively impacting adult transplant candidates.

Living Donor Liver Transplantation for Young Biliary Atresia Recipients Is Associated With Improved Outcomes in the Modern Era

INTRODUCTION

Biliary atresia (BA) is the most common indication for liver transplantation (LT) in children. We aimed to identify risk factors associated with survival in young patients with BA in the modern era.

METHODS

We performed a retrospective analysis of BA patients aged < 2 years who received their first isolated LT with available data from the United Network for Organ Sharing database (01/2013-12/2022). Factors included in the multivariable Cox regression were graft type, race/ethnicity, insurance status, laboratory pediatric end-stage liver disease (PELD) score, history of portal vein thrombosis, and intensive care unit (ICU) status.

RESULTS

1226 BA LT recipients aged < 2 years were included, of whom 501 (40.9%) received deceased donor whole grafts (DDWG), 425 (34.7%) received deceased donor technical variants (DDTV), and 300 (24.5%) received living donor LT (LDLT). LDLT recipients were more likely to be white (p = 0.008) and have private insurance (p < 0.001). Multivariable analysis demonstrated that ICU status (hazard ratio [HR] = 3.23, 95% confidence interval [95% CI]: 1.72-6.08, p < 0.001) and DDTV graft vs. LDLT (HR = 3.03, 95% CI: 1.14-8.04, p = 0.03) were associated with an increased risk of patient mortality. Factors associated with an increased risk of graft loss included ICU status (HR = 1.89, 95% CI: 1.19-3.00, p = 0.007) and both DDWG (HR = 3.37, 95% CI: 1.65-6.87, p = 0.001) and DDTV (HR = 3.47, 95% CI: 1.69-7.14, p = 0.001) grafts vs. LDLT.

CONCLUSION

LDLT is associated with improved survival in patients with BA aged < 2 years; however, socioeconomic differences exist between LDLT and non-LDLT recipients. Efforts to promote early equitable referral to centers offering LDLT are essential for improving outcomes in young children with BA.

Sex and Size Disparities in Access to Liver Transplant for Patients With Hepatocellular Carcinoma

Importance

Women on the liver transplant waiting list are less likely to undergo a transplant than men. Recent approaches to resolving this disparity have involved adjustments to Model for End-Stage Liver Disease (MELD) scoring, but this will not affect candidates who rely on exception scores rather than calculated MELD score, the majority of whom have hepatocellular carcinoma (HCC).

Objective

To evaluate the association between female sex, candidate size, and access to liver transplant among wait-listed patients with HCC.

Design, Setting, and Participants

This retrospective cohort study used US transplant registry data of all adult (aged ≥18 years) wait-listed liver transplant candidates receiving an HCC exception score between January 1, 2010, and March 2, 2023.

Exposure

Wait-listed liver transplant candidate sex.

Main Outcomes and Measures

The association of female sex with (1) deceased-donor liver transplant (DDLT) and (2) death or waiting list removal for health deterioration were estimated using multivariable competing-risks regression. Results with and without adjustment for candidate height and weight (mediators of the sex disparity) were compared.

Results

The cohort included 31 725 candidates with HCC (mean [SD] age at receipt of exception, 61.2 [7.1] years; 76.3% men). Compared with men, women had a lower 1-year cumulative incidence of DDLT (50.8% vs 54.0%; P < .001) and a higher 1-year cumulative incidence of death or delisting for health deterioration (16.2% vs 15.0%; P = .002). After adjustment, without accounting for size, women had a lower incidence of DDLT (subdistribution hazard ratio [SHR], 0.92; 95% CI, 0.89-0.95) and higher incidence of death or delisting (SHR, 1.06; 95% CI, 1.00-1.13) compared with men. When adjusting for candidate height and weight, there was no association of female sex with incidence of DDLT or death or delisting. However, at a height cutoff of 166 cm, short women compared with short men were still less likely to undergo a transplant (SHR, 0.93; 95% CI, 0.88-0.99).

Conclusions and Relevance

In this study, women with HCC were less likely to receive a DDLT and more likely to die while wait-listed than men with HCC; these differences were largely (but not entirely) explained by sex-based differences in candidate size. For candidates listed with exception scores, additional changes to allocation policy are needed to resolve the sex disparity, including solutions to improve access to size-matched donor livers for smaller candidates.

Pushing the Limits of In Situ Split Liver Procurement to Overcome Donor Distance and Graft Size Challenges for 8-Week-Old Pediatric Recipient

BACKGROUND

Pediatric liver transplantation for small recipients presents significant challenges, particularly in securing suitably sized donor organs. This case report illustrates the feasibility of performing an in situ split procurement in an 18.5-kg toddler, the smallest recorded case in the OPTN database to date, for a critically ill 8-week-old infant recipient.

CASE PRESENTATION

An 8-week-old infant with severe hepatitis of unknown etiology was urgently listed as Status 1A. An organ offer from a 3.5-year-old donor, requiring a reduction procedure, became available 1939 nautical miles away. Instead of a back-table reduction procedure, we performed an in situ split to reduce cold ischemic time given the distance. The recipient surgery was started ahead of the organ's arrival, and the recipient was ready for graft implantation upon the organ's arrival, resulting in a total of 510 min of cold ischemic time. Post-operatively, the graft did not show signs of significant injury or dysfunction, which expedited recovery from her other medical conditions.

CONCLUSIONS

In situ split liver procurement is an invaluable tool for pediatric centers as it effectively provides more graft options for pediatric patients on the waitlist. Additionally, in situ split can offer significant benefits in optimizing recipient surgery, especially when the donor is located at an extreme distance. Despite these benefits, in situ split is not currently widely utilized across transplant centers. Addressing the logistical challenges associated with this technique is crucial for broader implementation and improved patient outcomes.

Optimizing pediatric liver transplantation: Evaluating the impact of donor age and graft type on patient survival outcome

BACKGROUND

We examined the combined effects of donor age and graft type on pediatric liver transplantation outcomes with an aim to offer insights into the strategic utilization of these donor and graft options.

METHODS

A retrospective analysis was conducted using a national database on 0-2-year-old (N = 2714) and 3-17-year-old (N = 2263) pediatric recipients. These recipients were categorized based on donor age (≥40 vs <40 years) and graft type. Survival outcomes were analyzed using the Kaplan-Meier and Cox proportional hazards models, followed by an intention-to-treat (ITT) analysis to examine overall patient survival.

RESULTS

Living and younger donors generally resulted in better outcomes compared to deceased and older donors, respectively. This difference was more significant among younger recipients (0-2 years compared to 3-17 years). Despite this finding, ITT survival analysis showed that donor age and graft type did not impact survival with the exception of 0-2-year-old recipients who had an improved survival with a younger living donor graft.

CONCLUSIONS

Timely transplantation has the largest impact on survival in pediatric recipients. Improving waitlist mortality requires uniform surgical expertise at many transplant centers to provide technical variant graft (TVG) options and shed the conservative mindset of seeking only the "best" graft for pediatric recipients.

Utilization of older deceased donors for pediatric liver transplant may negatively impact long-term survival

BACKGROUND

Multiple adult studies have investigated the role of older donors (ODs) in expanding the donor pool. However, the impact of donor age on pediatric liver transplantation (LT) has not been fully elucidated.

METHODS

UNOS database was used to identify pediatric (≤18 years) LTs performed in the United States during 2002-22. Donors ≥40 years at donation were classified as older donors (ODs). Propensity analysis was performed with 1:1 matching for potentially confounding variables.

RESULTS

A total of 10,024 pediatric liver transplantation (PLT) patients met inclusion criteria; 669 received liver grafts from ODs. Candidates receiving OD liver grafts were more likely to be transplanted for acute liver failure, have higher Model End-Stage Liver Disease/Pediatric End-Stage Liver Disease (MELD/PELD) scores at LT, listed as Status 1/1A at LT, and be in the intensive care unit (ICU) at time of LT (all p < 0.001). Kaplan-Meier (KM) analyses showed that recipients of OD grafts had worse patient and graft survival (p < 0.001) compared to recipients of younger donor (YD) grafts. KM analyses performed on candidates matched for acuity at LT revealed inferior patient and graft survival in recipients of deceased donor grafts (p < 0.001), but not living donor grafts (p > 0.1) from ODs. Cox regression analysis demonstrated that living donor LT, diagnosis of biliary atresia and first liver transplant were favorable predictors of recipient outcomes, whereas ICU stay before LT and transplantation during 2002-12 were unfavorable.

CONCLUSION

Livers from ODs were used for candidates with higher acuity. Pediatric recipients of livers from ODs had worse outcome compared to YDs; however, living donor LT from ODs had the least negative impact on recipient outcomes.

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

BACKGROUND

End-stage liver disease (ESLD) and end-stage renal disease (ESRD) are prevalent diseases for which the definitive treatment is transplantation. With limited organ supply, strategies to maximize organ availability has led to increasing rates of split liver transplantations for ESLD patients. Therefore, simultaneous split liver and kidney transplantations (SSLK) for patients with ESLD and ESRD could represent a treatment option for comorbid patients. However, current practice and outcomes after SSLK are unknown.

METHODS

We aim to report national trends and our experience with patients undergoing SSLK. We performed a retrospective review of the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research file from January 2011-April 2022. Descriptive analysis of preoperative characteristics, postoperative outcomes and actuarial graft and patient survivals are reported.

RESULTS

National review of the UNOS transplant registry from 2011-2021 of adult patients undergoing initial transplantation via SSLK demonstrates that this procedure remains uncommon, with only 76 such cases captured in that time. Nevertheless, survival rates at 1, 3, and 5 years remains robust, at 94%, 92%, and 90% for patients overall, 90%, 88%, 88%, for the liver graft, and 93%, 91%, 88% for the kidney graft, respectively. Review of a single center experience with three such patients from 2019-2021 has shown a safe, enduring transplant option with no graft complications seen.

CONCLUSIONS

SSLK is both safe and a feasible option to optimize organ supply while allowing recipients to receive quality liver and kidney grafts and should be considered more often by transplant centers going forward.

Improving outcomes of in situ split liver transplantation in Italy over the last 25 years

BACKGROUND & AIMS

Split liver transplant(ation) (SLT) is still considered a challenging procedure that is by no means widely accepted. We aimed to present data on 25-year trends in SLT in Italy, and to investigate if, and to what extent, outcomes have improved nationwide during this time.

METHODS

The study included all consecutive SLTs performed from May 1993 to December 2019, divided into three consecutive periods: 1993-2005, 2006-2014, and 2015-2019, which match changes in national allocation policies. Primary outcomes were patient and graft survival, and the relative impact of each study period.

RESULTS

SLT accounted for 8.9% of all liver transplants performed in Italy. A total of 1,715 in situ split liver grafts were included in the analysis: 868 left lateral segments (LLSs) and 847 extended right grafts (ERGs). A significant improvement in patient and graft survival (p <0.001) was observed with ERGs over the three periods. Predictors of graft survival were cold ischaemia time (CIT) <6 h (p = 0.009), UNOS status 2b (p <0.001), UNOS status 3 (p = 0.009), and transplant centre volumes: 25-50 cases vs. <25 cases (p = 0.003). Patient survival was significantly higher with LLS grafts in period 2 vs. period 1 (p = 0.008). No significant improvement in graft survival was seen over the three periods, where predictors of graft survival were CIT <6 h (p = 0.007), CIT <6 h vs. ≥10 h (p = 0.019), UNOS status 2b (p = 0.038), and UNOS status 3 (p = 0.009). Retransplantation was a risk factor in split liver graft recipients, with significantly worse graft and patient survival for both types of graft (p <0.001).

CONCLUSIONS

Our analysis showed Italian SLT outcomes to have improved over the last 25 years. These results could help to dispel reservations regarding the use of this procedure.

IMPACT AND IMPLICATIONS

Split liver transplant(ation) (SLT) is still considered a challenging procedure and is by no means widely accepted. This study included all consecutive in situ SLTs performed in Italy from May 1993 to December 2019. With more than 1,700 cases, it is one of the largest series, examining long-term national trends in in situ SLT since its introduction. The data presented indicate that the outcomes of SLT improved during this 25-year period. Improvements are probably due to better recipient selection, refinements in surgical technique, conservative graft-to-recipient matching, and the continuous, yet carefully managed, expansion of donor selection criteria under a strict mandatory split liver allocation policy. These results could help to dispel reservations regarding the use of this procedure.

Center use of technical variant grafts varies widely and impacts pediatric liver transplant waitlist and recipient outcomes in the United States

To assess the impact of technical variant grafts (TVGs) [including living donor (LD) and deceased donor split/partial grafts] on waitlist (WL) and transplant outcomes for pediatric liver transplant (LT) candidates, we performed a retrospective analysis of Organ Procurement and Transplantation Network (OPTN) data on first-time LT or liver-kidney pediatric candidates listed at centers that performed >10 LTs during the study period, 2004-2020. Center variance was plotted for LT volume, TVG usage, and survival. A composite center metric of TVG usage and WL mortality was developed to demonstrate the existing variation and potential for improvement. Sixty-four centers performed 7842 LTs; 657 children died on the WL. Proportions of WL mortality by center ranged from 0% to 31% and those of TVG usage from 0% to 76%. Higher TVG usage, from deceased donor or LD, independently or in combination, significantly correlated with lower WL mortality. In multivariable analyses, death from listing was significantly lower with increased center TVG usage (HR = 0.611, CI: 0.40-0.92) and LT volume (HR = 0.995, CI: 0.99-1.0). Recipients of LD transplants (HR = 0.637, CI: 0.51-0.79) had significantly increased survival from transplant compared with other graft types, and recipients of deceased donor TVGs (HR = 1.066, CI: 0.93-1.22) had statistically similar outcomes compared with whole graft recipients. Increased TVG utilization may decrease WL mortality in the US. Hence, policy and training to increase TVG usage, availability, and expertise are critical.

Addressing sex-based disparities in solid organ transplantation in the United States - a conference report

Solid organ transplantation provides the best treatment for end-stage organ failure, but significant sex-based disparities in transplant access exist. On June 25, 2021, a virtual multidisciplinary conference was convened to address sex-based disparities in transplantation. Common themes contributing to sex-based disparities were noted across kidney, liver, heart, and lung transplantation, specifically the existence of barriers to referral and wait listing for women, the pitfalls of using serum creatinine, the issue of donor/recipient size mismatch, approaches to frailty and a higher prevalence of allosensitization among women. In addition, actionable solutions to improve access to transplantation were identified, including alterations to the current allocation system, surgical interventions on donor organs, and the incorporation of objective frailty metrics into the evaluation process. Key knowledge gaps and high-priority areas for future investigation were also discussed.

An appraisal of technical variant grafts compared to whole liver grafts in pediatric liver transplant recipients: Multicenter analysis from the SPLIT registry

BACKGROUND

Shortages of liver allografts for children awaiting transplantation have led to high LT waitlist mortality. Prior studies have shown that usage of TVG can reduce waiting time and waitlist mortality, but their use is not universal. We sought to compare patient and graft survival between WLG and TVG and to identify potential associated risk factors in a contemporary pediatric LT cohort.

METHODS

We performed a retrospective analysis of patient survival, graft survival, and biliary and vascular complications for LT recipients <18 years old entered into the Society of Pediatric Liver Transplantation prospective multicenter database.

RESULTS

Of 1839 LT recipients, 1029 received a WLG and 810 received a TVG from either a LD or a DD. There was no difference in patient survival or graft survival by graft type. Three-year patient survival and graft survival were 96%, 93%, and 96%, and 95%, 89%, and 92% for TVG-LD, TVG-DD, and WLG, respectively. Biliary complications were more frequent in TVG. Hepatic artery thrombosis was more frequent in WLG. Multivariate analysis revealed primary diagnosis was the only significant predictor of patient survival. Predictors for graft survival included time-dependent development of biliary and vascular complications.

CONCLUSIONS

There were no significant differences in patient and graft survival based on graft types in this North American multi-center pediatric cohort. Widespread routine use of TVG should be strongly encouraged to decrease mortality on the waitlist for pediatric LT candidates.

Chinese expert consensus on evaluation of donor and donor liver for split liver transplantation

With the advent of the era of organ donation after citizen's death, split liver transplantation (SLT) can effectively increase the supply of donor livers and shorten the transplantation wait time for patients, especially pediatric recipients. In recent years, SLT has been performed to varying degrees in many transplant centers in China, and varying levels of efficacy have been achieved. The quality of donors and donor livers for SLT is an important factor affecting the outcome of the surgery. At this stage, it is necessary to reach a consensus on the evaluation of SLT donor and liver donor that is suitable for the conditions in China by combining the well-established experience of the international community with advanced transplantation technology. This approach will aid in enhancing the efficacy of SLT. Based on the experience of experts, a consensus on the evaluation of donors and donor livers for SLT has been formulated in this study, which focuses on evaluation of donors and donor livers, evaluating the functional and anatomical aspects of the donor liver and donor-recipient matching.

Survival Benefit of Split-Liver Transplantation for Pediatric and Adult Candidates

Patient and graft survival are similar following whole-liver transplantations (WLTs) versus split-liver transplantations (SLTs) among pediatric and adult recipients, yet SLTs are rarely used. We sought to determine the survival benefit associated with accepting a splittable graft offer for SLT versus declining and waiting for a subsequent offer using 2010 to 2018 Scientific Registry of Transplant Recipients (SRTR) data on 928 pediatric and 1814 adult liver transplantation candidates who were ever offered a splittable graft. We compared eventual mortality, regardless of subsequent transplants, between those patients who accepted versus declined a split liver offer with adjustments for Pediatric End-Stage Liver Disease/Model for End-Stage Liver Disease (MELD) scores, diagnosis, and weight among pediatric candidates and matching for MELD score, height, and offer among adult candidates. Among pediatric candidates ≤7 kg, split liver offer acceptance versus decline was associated with a 63% reduction in mortality (adjusted hazard ratio [aHR], _0.17 0.37_0.80 [P = 0.01]; 93.1% versus 84.0% 1-year survival after decision). Within 1 year of decline for those ≤7 kg, 6.4% died and 31.1% received a WLT. Among pediatric candidates >7 kg, there was no significant difference associated with acceptance of a split liver offer (aHR, _0.63 1.07_1.82 [P = 0.81]; 91.7% versus 94.4% 1-year survival after decision). Within 1 year of decline for those >7 kg, 1.8% died and 45.8% received a WLT. Among adult candidates, split liver offer acceptance was associated with a 43% reduction in mortality (aHR, _0.39 0.57_0.83 [P = 0.005]; 92.2% versus 84.4% 1-year survival after decision). Within 1 year of decline for adult candidates, 7.9% died and 39.3% received a WLT. Accepting split liver offers for SLT could significantly improve survival for small children and adults on the waiting list.

Pediatric living donor liver transplantation using liver allograft after ex vivo backtable resection of hemangioma: A case report

BACKGROUND

Use of liver allograft with hepatic hemangioma after in vivo resection of hemangioma in living donor liver transplantation (LDLT) has been previously reported. However, there are few reports describing ex vivo backtable resection of hemangioma from liver allografts in LDLT.

CASE SUMMARY

A 55-year-old male was evaluated as a donor for an 8-month-year old patient with acute hepatic failure due to biliary atresia. Pre-operative contrast enhanced computed tomography revealed a 9 cm hemangioma in segment 4 with vascular variations in the donor. During LDLT, an intra-operative intrahepatic cholangiography was performed to ensure no variation in the anatomy of the intrahepatic bile duct. After intra-operative pathological diagnosis, ex vivo backtable resection of the hemangioma was performed and the liver allograft was transplanted into the recipient. The donor’s and recipient’s post-operative course were uneventful. At the 2-year follow-up, the liver allograft showed good regeneration without any recurrence of hemangioma.

CONCLUSION

Liver allografts with hemangiomas are an acceptable alternative strategy for LDLT. Ex vivo backtable resection of hemangioma from the donor liver during pediatric LDLT is safe and feasible, and can effectively reduce the operative time and intra-operative bleeding for the donor.

Variability of Care and Access to Transplantation for Children with Biliary Atresia Who Need a Liver Replacement

Background & Aims: Biliary atresia (BA) is the commonest single etiology indication for liver replacement in children. As timely access to liver transplantation (LT) remains challenging for small BA children (with prolonged waiting time being associated with clinical deterioration leading to both preventable pre- and post-transplant morbidity and mortality), the care pathway of BA children in need of LT was analyzed—from diagnosis to LT—with particular attention to referral patterns, timing of referral, waiting list dynamics and need for medical assistance before LT. Methods: International multicentric retrospective study. Intent-to-transplant study analyzing BA children who had indication for LT early in life (aged < 3 years at the time of assessment), over the last 5 years (2016−2020). Clinical and laboratory data of 219 BA children were collected from 8 transplant centers (6 in Europe and 2 in USA). Results: 39 patients underwent primary transplants. Children who underwent Kasai in a specialist -but not transplant- center were older at time of referral and at transplant. At assessment for LT, the vast majority of children already were experiencing complication of cirrhosis, and the majority of children needed medical assistance (nutritional support, hospitalization, transfusion of albumin or blood) while waiting for transplantation. Severe worsening of the clinical condition led to the need for requesting a priority status (i.e., Peld Score exception or similar) for timely graft allocation for 76 children, overall (35%). Conclusions: As LT currently results in BA patient survival exceeding 95% in many expert LT centers, the paradigm for BA management optimization and survival have currently shifted to the pre-LT management. The creation of networks dedicated to the timely referral to a pediatric transplant center and possibly centralization of care should be considered, in combination with implementing all different graft type surgeries in specialist centers (including split and living donor LTs) to achieve timely LT in this vulnerable population.

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

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.

A Novel Strategy for Preventing Posttransplant Large-For-Size Syndrome in Adult Liver Transplant Recipients: A Pilot Study

There are two causes of graft compression in the large-for-size syndrome (LFSS). One is a shortage of intra-abdominal space for the liver graft, and the other is the size discrepancy between the anteroposterior dimensions of the liver graft and the lower right hemithorax of the recipient. The former could be treated using delayed fascial closure or mesh closure, but the latter may only be treated by reduction of the right liver graft to increase space. Given that split liver transplantation has strict requirements regarding donor and recipient selections, reduced-size liver transplantation, in most cases, may be the only solution. However, surgical strategies for the reduction of the right liver graft for adult liver transplantations are relatively unfamiliar. Herein, we introduce a novel strategy of HuaXi-ex vivo right posterior sectionectomy while preserving the right hepatic vein in the graft to prevent LFSS and propose its initial indications.

Challenging the Traditional Paradigm of Supply and Demand in Pediatric Liver Transplantation Through Nondirected Living Donation: A Case Series

A gap exists between the demand for pediatric liver transplantation and the supply of appropriate size-matched donors. We describe our center's experience with pediatric liver transplantation using anonymous nondirected living liver donors (ND-LLD). First-time pediatric liver transplant candidates listed at our center between January 2012 and June 2020 were retrospectively reviewed and categorized by donor graft type, and recipients of ND-LLD grafts were described. A total of 13 ND-LLD pediatric liver transplantations were performed, including 8 left lateral segments, 4 left lobes, and 1 right lobe. Of the ND-LLD recipients, 5 had no directed living donor evaluated, whereas the remaining 8 (62%) had all potential directed donors ruled out during the evaluation process. Recipient and graft survival were 100% during a median follow-up time of 445 (range, 70-986) days. Of ND-LLDs, 69% were previous living kidney donors, and 1 ND-LLD went on to donate a kidney after liver donation. Of the ND-LLDs, 46% were approved prior to the recipient being listed. Over time, the proportion of living donor transplants performed, specifically from ND-LLDs, increased, and the number of children on the waiting list decreased. The introduction of ND-LLDs to a pediatric liver transplant program can expand the benefit of living donor liver transplantation to children without a suitable directed living donor while achieving excellent outcomes for both the recipients and donors.

A review of split liver transplantation with full right/left hemi-liver grafts for 2 adult recipients

Liver transplantation has become a routine operation in many transplantation centers worldwide. However, liver graft availability fails to meet patient demands. Split liver transplantation (SPLT), which divides a deceased donor liver into 2 partial liver grafts, is a promising strategy for increasing graft availability for transplantation and ameliorating organ shortage to a certain degree. However, the transplantation community has not yet reached a consensus on SPLT because of the variable results. Specifically, SPLT for 2 adult recipients using full right/left hemi-liver grafts is clinically more challenging in terms of surgical technique and potential postoperative complications. Therefore, this review summarizes the current status of SPLT, focusing on the transplantation of adult recipients. Furthermore, the initiation of the SPLT program, donor allocation, surgical aspects, recipient outcomes, and obstacles to developing this procedure will be thoroughly discussed. This information might help provide an optimal strategy for implementing SPLT for 2 adult recipients among current transplantation societies. Meanwhile, potential obstacles to SPLT might be overcome in the near future with growing knowledge, experience, and refinement of surgical techniques. Ultimately, the widespread diffusion of SPLT may increase graft availability and mitigate organ donation shortages.

The Surge in Deceased Liver Donors Due to the Opioid Epidemic: Is It Time to Split the Difference?

BACKGROUND

This study aimed to compare trends in use of drug overdose (DO) donors in adult versus pediatric liver transplants and the utilization of split liver transplantation in this donor population.

METHODS

The United Network for Organ Sharing database was reviewed for deceased donor liver transplants from March 2002 to December 2017. Recipients were categorized by donor mechanism of death. Donor splitting criteria was defined as age <40 y, single vasopressor or less, transaminases no >3 times the normal limit, and body mass index ≤ 28 kg/m2.

RESULTS

Adult liver transplants from DO donors increased from 2% in 2002 to 15% in 2017, while pediatric liver transplants from DO donors only increased from <1% to 3% in the same time. While 28% of DO donors met splitting criteria, only 3% of those meeting splitting criteria were used as a split graft. Both pediatric and adult recipients of DO donor livers achieved excellent patient and graft survival.

CONCLUSIONS

DO donors are underutilized in pediatric liver transplantation. Increased splitting of DO donor livers could significantly decrease, if not eliminate, the pediatric liver waiting list.

Liver simulated allocation model does not effectively predict organ offer decisions for pediatric liver transplant candidates

The SRTR maintains the liver-simulated allocation model (LSAM), a tool for estimating the impact of changes to liver allocation policy. Integral to LSAM is a model that predicts the decision to accept or decline a liver for transplant. LSAM implicitly assumes these decisions are made identically for adult and pediatric liver transplant (LT) candidates, which has not been previously validated. We applied LSAM's decision-making models to SRTR offer data from 2013 to 2016 to determine its efficacy for adult (≥18) and pediatric (<18) LT candidates, and pediatric subpopulations-teenagers (≥12 to <18), children (≥2 to <12), and infants (<2)-using the area under the receiver operating characteristic (ROC) curve (AUC). For nonstatus 1A candidates, all pediatric subgroups had higher rates of offer acceptance than adults. For non-1A candidates, LSAM's model performed substantially worse for pediatric candidates than adults (AUC 0.815 vs. 0.922); model performance decreased with age (AUC 0.898, 0.806, 0.783 for teenagers, children, and infants, respectively). For status 1A candidates, LSAM also performed worse for pediatric than adult candidates (AUC 0.711 vs. 0.779), especially for infants (AUC 0.618). To ensure pediatric candidates are not unpredictably or negatively impacted by allocation policy changes, we must explicitly account for pediatric-specific decision making in LSAM.

Considering extended right lobe grafts as major extended donor criteria in liver transplantation is justified

The outcomes of split-liver transplantation are controversial. This study compared outcomes and morbidity after extended right lobe liver transplantation (ERLT) and whole liver transplantation (WLT) in adults. MEDLINE and Web of Science databases were searched systematically and unrestrictedly for studies on ERLT and its impact on graft and patient survival, and postoperative complications. Graft loss and patient mortality odds ratios (OR) and 95% confidence intervals (CI) were assessed by meta-analyses using Mantel-Haenszel tests with a random-effects model. Vascular and biliary complications, primary nonfunction, 3-month, 1-, and 3-year graft and patient survival, and retransplantation after ERLT and WLT were analyzed. The literature search yielded 10 594 articles. After exclusion, 22 studies (n = 75 799 adult transplant patients) were included in the analysis. ERLT was associated with lower 3-month (OR = 1.43, 95% CI = 1.09-1.89, P = 0.01), 1-year (OR = 1.46, 95% CI = 1.08-1.97, P = 0.01), and 3-year (OR = 1.37, 95% CI = 1.01-1.84, P = 0.04) graft survival. WL grafts were less associated with retransplantation (OR = 0.57; 95% CI = 0.41-0.80; P < 0.01), vascular complications (OR = 0.53, 95% CI = 0.38-0.74, P < 0.01) and biliary complications (OR = 0.67; 95% CI = 0.47-0.95; P = 0.03). Considering ERLT as major Extended Donor Criteria is justified because ERL grafts are associated with vasculobiliary complications and the need for retransplantation, and have a negative influence on graft survival.

Ex Situ Dual Hypothermic Oxygenated Machine Perfusion for Human Split Liver Transplantation

Supplemental Digital Content is available in the text.

Liver splitting allows the opportunity to share a deceased graft between 2 recipients but remains underutilized. We hypothesized that liver splitting during continuous dual hypothermic oxygenated machine perfusion (DHOPE) is feasible, with shortened total cold ischemia times and improved logistics. Here, we describe a left lateral segment (LLS) and extended right lobe (ERL) liver split procedure during continuous DHOPE preservation with subsequent transplantation at 2 different centers.

Outcomes of hemi- versus whole liver transplantation in patients from mainland china with high model for end-stage liver disease scores: a matched analysis

Background

Adult hemiliver transplantation (AHLT) is an important approach given the current shortage of donor livers. However, the suitability of AHLT versus adult whole liver transplantation (AWLT) for recipients with high Model for End-Stage Liver Disease (MELD) scores remains controversial.

Methods

We divided patients undergoing AHLT and AWLT into subgroups according to their MELD scores (≥ 30: AHLT, n = 35; AWLT, n = 88; and < 30: AHLT, n = 323; AWLT, n = 323). Patients were matched by demographic data and perioperative conditions according to propensity scores. A cut-off value of 30 for MELD scores was determined by comparing the overall survival data of 735 cases of nontumor liver transplantation.

Results

Among patients with an MELD score ≥ 30 and < 30, AHLT was found to be associated with increased warm ischemia time, operative time, hospitalization time, and intraoperative blood loss compared with AWLT (P < 0.05). In the MELD ≥ 30 group, although the 5-year survival rate was significantly higher for AWLT than for AHLT (P = 0.037), there was no significant difference between AWLT and AHLT in the MELD < 30 group (P = 0.832); however, we did not observe a significant increase in specific complications following AHLT among patients with a high MELD score (≥ 30). Among these patients, the incidence of complications classified as Clavien-Dindo grade III or above was significantly higher in patients undergoing AHLT than in those undergoing AWLT (25.7% vs. 11.4%, P = 0.047). For the MELD < 30 group, there was no significant difference in the incidence of complications classified as Clavien-Dindo grade III or above for patients undergoing AHLT or AWLT.

Conclusion

In patients with an MELD score < 30, AHLT can achieve rates of mortality and overall survival comparable to AWLT. In those with an MELD score ≥ 30, the prognosis and incidence of complications classified as Clavien-Dindo III or above are significantly worse for AHLT than for AWLT; therefore, we may need to be more cautious regarding the conclusion that patients with a high MELD score can safely undergo AHLT.