Whole Liver Versus Split Liver Versus Living Donor in the Adult Recipient—An Analysis of Outcomes by Graft Type

Current Understanding of Marginal Grafts in Liver Transplantation

End-stage liver disease (ESLD), stemming from a spectrum of chronic liver pathologies including chronic liver failure, acute cirrhosis decompensation and hepatocellular carcinoma, imposes a significant global healthcare burden. Liver transplantation (LT) remains the only treatment for ESLD. However, the escalating mortality on transplant waitlists has prompted the utilization of marginal liver grafts in LT procedures. These grafts primarily encompass elderly livers, steatotic livers, livers from donation after circulatory death, split livers and those infected with the hepatitis virus. While the expansion of the donor pool offers promise, it also introduces concomitant risks. These encompass graft failure, biliary and cardiovascular complications, the recurrence of liver disease and reduced patient and graft survival. Consequently, various established strategies, ranging from improved donor-recipient matching to surgical interventions, have emerged to mitigate these risks. This article undertakes a comprehensive assessment of the current landscape, evaluating the viability of diverse marginal liver grafts. Additionally, it synthesizes approaches aimed at enhancing the quality of such marginal liver grafts. The overarching objective is to augment the donor pool and ameliorate the risk factors associated with the shortage of liver grafts.

Biliary atresia and liver transplantation in the United States: A contemporary analysis

BACKGROUND

Biliary atresia (BA) remains the number one indication for paediatric liver transplantation (LT) worldwide but is an uncommon indication for older LT recipients. The impact of recent donor allocation changes, pervasive organ shortage and evolving LT practices on the BA LT population is unknown.

METHODS

We identified patients who underwent LT between January 2010 and December 2021 using the UNOS database. We compared clinical outcomes between patients with BA and those with non-BA cholestatic liver disease. Groups were stratified by age, <12 years (allocated via PELD system) and ≥12 years (allocated via MELD system). Waitlist outcomes were compared using competing-risk regression analysis, graft survival rates were compared using Kaplan-Meier time-to-event analysis and Cox proportional hazards modelling provided adjusted estimates.

RESULTS

There were 2754 BA LT waitlist additions and 2206 BA LTs (1937 <12 years [younger], 269 ≥12 years [older]). There were no differences in waitlist mortality between BA and non-BA cholestatic patients. Among BA LT recipients, there were 441 (20.0%) living-donor liver transplantations (LDLT) and 611 (27.7%) split deceased-donor LTs. Five-year graft survival was significantly higher among BA versus non-BA cholestatic patients in the older group (88.3% vs. 79.5%, p < .01) but not younger group (89.3% vs. 89.5%). Among BA LT recipients, improved graft outcomes were associated with LDLT (vs. split LT: HR: 2, 95% CI: 1.03-3.91) and higher transplant volume (volume >100 vs. <40 BA LTs: HR: 3.41, 95% CI: 1.87-6.2).

CONCLUSION

Liver transplant outcomes among BA patients are excellent, with LDLT and higher transplant centre volume associated with optimal graft outcomes.

Outcome of split liver transplantation vs living donor liver transplantation: A systematic review and meta-analysis

BACKGROUND

The outcomes of liver transplantation (LT) from different grafts have been studied individually and in combination, but the reports were conflicting with some researchers finding no difference in both short-term and long-term outcomes between the deceased donor split LT (DD-SLT) and living donor LT (LDLT).

AIM

To compare the outcomes of DD-SLT and LDLT we performed this systematic review and meta-analysis.

METHODS

This systematic review was performed in compliance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. The following databases were searched for articles comparing outcomes of DD-SLT and LDLT: PubMed; Google Scholar; Embase; Cochrane Central Register of Controlled Trials; the Cochrane Database of Systematic Reviews; and Reference Citation Analysis (https://www.referencecitationanalysis.com/). The search terms used were: "liver transplantation;" "liver transplant;" "split liver transplant;" "living donor liver transplant;" "partial liver transplant;" "partial liver graft;" "ex vivo splitting;" and "in vivo splitting."

RESULTS

Ten studies were included for the data synthesis and meta-analysis. There were a total of 4836 patients. The overall survival rate at 1 year, 3 years and 5 years was superior in patients that received LDLT compared to DD-SLT. At 1 year, the hazard ratios was 1.44 (95% confidence interval: 1.16-1.78; P = 0.001). The graft survival rate at 3 years and 5 years was superior in the LDLT group (3 year hazard ratio: 1.28; 95% confidence interval: 1.01-1.63; P = 0.04).

CONCLUSION

This meta-analysis showed that LDLT has better graft survival and overall survival when compared to DD-SLT.

Full-left-full-right split liver transplantation for adult recipients: a systematic review and meta-analysis

Full-left-full-right split liver transplantation (FSLT) for adult recipients, may increase the availability of liver grafts, reduce waitlist time, and benefit recipients with below-average body weight. However, FSLT may lead to impaired graft and patient survival. This study aims to assess outcomes after FSLT. Five databases were searched to identify studies concerning FSLT. Incidences of complications, graft- and patient survival were assessed. Discrete data were pooled with random-effect models. Graft and patient survival after FSLT were compared with whole liver transplantation (WLT) according to the inverse variance method. Vascular complications were reported in 25/273 patients after FSLT (Pooled proportion: 6.9%, 95%CI: 3.1-10.7%, I² : 36%). Biliary complications were reported in 84/308 patients after FSLT (Pooled proportion: 25.6%, 95%CI: 19-32%, I² : 44%). Pooled proportions of graft and patient survival after 3 years follow-up were 72.8% (95%CI: 67.2-78.5, n = 231) and 77.3% (95%CI: 66.7-85.8, n = 331), respectively. Compared with WLT, FSLT was associated with increased graft loss (pooled HR: 2.12, 95%CI: 1.24-3.61, P = 0.006, n = 189) and patient mortality (pooled HR: 1.81, 95%CI: 1.17-2.81, P = 0.008, n = 289). FSLT was associated with high incidences of vascular and biliary complications. Nevertheless, long-term patient and graft survival appear acceptable and justify transplant benefit in selected patients.

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.

Association of Donor and Recipient Cytomegalovirus Serostatus on Graft and Patient Survival in Liver Transplant Recipients

Among solid organ transplant recipients, donor cytomegalovirus (CMV) seropositive (D+) and recipient seronegative (R-) status are associated with an increased risk of graft loss and mortality after kidney or lung transplantation. Whether a similar relationship exists among liver transplant recipients (LTR) is unknown. We assessed graft loss and mortality among adult LTRs from January 1, 2010, to March 14, 2020, in the Organ Procurement and Transplantation Network database. We used multivariable mixed Cox proportional hazards regression to analyze the association of donor and recipient CMV serostatus group with graft loss and mortality, with donor seronegative (D-) and recipient seronegative (R-) as the reference group. Among 54,078 LTRs, the proportion of D-R-, D- and recipient seropositive (R+), D+R-, and D+R+ was 13.4%, 22.5%, 22%, and 42%, respectively. By unadjusted Kaplan-Meier survival curve estimates, survival by the end of follow-up was 73.3%, 73.5%, 70.1%, and 69.7%, among the D-R-, D-R+, D+R-, and D+R+ groups, respectively. By multivariable Cox regression, the CMV D+R- serogroup, but not other serogroups, was independently associated with increased risks of graft loss (adjusted hazard ratio [aHR], 1.13; 95% confidence interval [CI], 1.05-1.22) and mortality (aHR, 1.13; 95% CI, 1.05-1.22). The magnitude of the association of the CMV D+R- serostatus group with mortality was similar when the Cox regression analysis was restricted to the first year after transplant and beyond the first year after transplant: aHR, 1.13 (95% CI, 1.01-1.27) and aHR, 1.13 (95% CI, 1.02-1.25), respectively. Even in an era of CMV preventive strategies, CMV D+R- serogroup status remains independently associated with increased graft loss and mortality in adult LTRs. Factors in addition to direct CMV-associated short-term mortality are likely, and studies to define the underlying mechanism(s) are warranted.

Addressing the challenges of split liver transplantation through technical advances. A systematic review

BACKGROUND

Split liver transplantation addresses donor shortages by facilitating the transplant of two recipients using one donor liver. Some still consider these grafts inferior due to prolonged cold ischaemia time and at times difficult vascular reconstruction. Techniques such as in-situ splitting, machine perfusion and interposition grafts may address these challenges and thereby address these concerns. The aim of this review is to assess these technical advances in split liver transplantation, their utility and outcomes.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Keywords included 'split liver transplantation', 'arterial reconstruction', and 'machine perfusion'. Data found was synthesised into sections including: methods of splitting, full-left full-right splitting, donor cholangiography, machine perfusion and arterial reconstruction.

RESULTS

A total of 78 articles met inclusion criteria after screening of 151 eligible articles. These were subdivided into the following categories: in-situ (25), ex-vivo (25), full-left full-right splitting (15), donor cholangiography (2), machine perfusion (6), and arterial reconstruction (5). The in-situ splitting technique reduces the cold ischaemia time compared to the ex-vivo technique which may improve graft quality and liver splitting during normothermic machine perfusion is a novel technique with the potential to incorporate the best aspects of both techniques. Interposition grafts are often required during split liver transplantation but have an increased risk of hepatic artery thrombosis.

CONCLUSION

Advancements in technique have allowed many of the unique challenges of split liver transplantation to be overcome. Overall, this supports the use of split liver transplantation in broader and riskier settings and we advocate for liver transplant surgeons to not hesitate in using these grafts liberally and expanding their recipient selection criteria.

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.

Is there an ethical obligation to split every donor liver? Scarce resources, medical factors, and ethical reasoning

SLT has the potential to counter the worldwide shortage of donor organs. Although the preferred recipients of SLT are usually pediatric patients, a more stringent ethical argument than the fundamental prioritization of children is to demonstrate that SLT of deceased donor organs could increase access to this potentially lifesaving resource for all patients, including children. Several empirical studies show that SLT also makes it possible to achieve similar outcomes to WLT in adults if several factors are observed. In general, it can be regarded as ethically permissible to insist on splitting a donor liver if, in an individual case, SLT is expected to have a similar outcome to that of WLT. The question is therefore no longer whether, but under what conditions SLT is able to achieve similar results to WLT. One of the main challenges of the current debate is the restricted comparability of the available data. We therefore have an ethical obligation to improve the available empirical data by implementing prospective clinical studies, SLT programs, and national registries. The introduction of 2 modes of allocation-one for patients willing to accept both SLT and WLT, and a second for patients only willing to accept WLT-would help to resolve the issue of patient autonomy in the case of mandatory splitting policy.

Split versus living-related adult liver transplantation: a systematic review and meta-analysis

BACKGROUND-OBJECTIVE

The outcomes of split liver transplantation between recipients of deceased donor split liver transplant (SLT) or live donor liver transplants (LDLT) have never been compared in meta-analysis. It is important to understand graft and recipient survival between recipients of these grafts.

METHODS

Databases were searched for relevant articles over the previous 20 years (MEDLINE, Embase, Cochrane Library and Google Scholar). Meta-analyses were performed using both fixed- and random-effects models. Patient survival and graft survival were obtained using the inverse variance hazard ratio method.

RESULTS

There were differences in the characteristics of the donors and recipients. Donors of the SLT were younger compared to LDLT cohort [mean difference (MD) = - 11.12 years (- 15.41 to - 6.84), p < 0.001] whilst recipients of LDLT were younger [MD = - 2.06 years (- 1.12 to - 3.01), p < 0.001]. Significantly fewer men received grafts after SLT, 45%, compared to those receiving LDLT, 55%, [OR = 0.66 (0.55 to 0.80), p < 0.001]. There were no significant differences detected in postoperative complications, graft and patient 1-, 3- and 5-year survival between the SLT and LDLT cohorts.

CONCLUSIONS

There is no apparent difference in overall survival, graft survival or complications between recipients of SLT or LDLT. However, characteristics of the donor and recipients differed suggesting the need for adequate risk-adjusted assessment of outcomes.

Higher retransplantation rate following extended right split-liver transplantation: An analysis from the eurotransplant liver follow-up registry

Split-liver transplantation has been perceived as an important strategy to increase the supply of liver grafts by creating 2 transplants from 1 allograft. The Eurotransplant Liver Allocation System (ELAS) envisages that the extended right lobes (ERLs) after splitting (usually in the pediatric center) are almost exclusively shipped to a second center. Whether the ELAS policy impacts the graft and patient survival of extended right lobe transplantation (ERLT) in comparison to whole liver transplantation (WLT) recipients remains unclear. Data on all liver transplantations performed between 2007 and 2013 were retrieved from the Eurotransplant Liver Follow-up Registry (n = 5351). Of these, 5013 (269 ERL, 4744 whole liver) could be included. The impact of the transplant type on patient and graft survival was evaluated using univariate and multivariate proportional hazard models adjusting for demographics of donors and recipients. Cold ischemia times were significantly prolonged for ERLTs (P < 0.001). Patient survival was not different between ERLT and WLT. In the univariate analysis, ERLT had a significantly higher risk for retransplantation (P = 0.02). For WLT, the risk for death gradually and significantly increased with laboratory Model for End-Stage Liver Disease (MELD) scores of >20. For ERLT, this effect was seen already with laboratory MELD scores of >14. These results mandate a discussion on how to refine the splitting policy to avoid excess retransplant rates in ERL recipients and to further improve transplant outcomes of these otherwise optimal donor organs. Liver Transplantation 24 26-34 2018 AASLD.

Using on-site liver 3-D reconstruction and volumetric calculations in split liver transplantation

BACKGROUND

Split liver transplantation increases the number of grafts available for transplantation. Pre-recovery assessment of liver graft volume is essential for selecting suitable recipients. The purpose of this study was to determine the ability and feasibility of constructing a 3-D model to aid in surgical planning and to predict graft weight prior to an in situ division of the donor liver.

METHODS

Over 11 months, 3-D volumetric reconstruction of 4 deceased donors was performed using Pathfinder Scout© liver volumetric software. Demographic, laboratory, operative, perioperative and survival data for these patients along with donor demographic data were collected prospectively and analyzed retrospectively.

RESULTS

The average predicted weight of the grafts from the adult donors obtained from an in situ split procedure were 1130 g (930-1458 g) for the extended right lobe donors and 312 g (222-396 g) for left lateral segment grafts. Actual adult graft weight was 92% of the predicted weight for both the extended right grafts and the left lateral segment grafts. The predicted and actual graft weights for the pediatric donors were 176 g and 210 g for the left lateral segment grafts and 308 g and 280 g for the extended right lobe grafts, respectively. All grafts were transplanted except for the right lobe from the pediatric donors due to the small graft weight.

CONCLUSIONS

On-site volumetric assessment of donors provides useful information for the planning of an in situ split and for selection of recipients. This information may expand the donor pool to recipients previously felt to be unsuitable due to donor and/or recipient weight.

Long-term results after adult ex situ split liver transplantation since its introduction in 1987

BACKGROUND

Split liver transplantation is still discussed controversially. Utilization of split liver grafts has been declining since a change of allocation rules for the second graft abolished incentives for German centres to perform ex situ splits. We therefore analysed our long-term experiences with the first ex situ split liver transplant series worldwide.

METHODS

A total of 131 consecutive adult ex situ split liver transplants (01.12.1987-31.12.2010) were analysed retrospectively.

RESULTS

Thirty-day mortality rates and 1- and 3-year patient survival rates were 13, 76.3, and 66.4 %, respectively. One- and three-year graft survival rates were 63.4 and 54.2 %, respectively. The observed 10-year survival rate was 40.6 %. Continuous improvement of survival from era 1 to 3 was observed (each era: 8 years), indicating a learning curve over 24 years of experience. Patient and graft survival were not influenced by different combinations of transplanted segments or types of biliary reconstruction (p > 0.05; Cox regression). Patients transplanted for primary sclerosing cholangitis had better survival (p = 0.021; log-rank), whereas all other indications including acute liver failure (13.6 %), acute and chronic graft failure (9.1 %) had no significant influence on survival (p > 0.05; log-rank). Biliary complications (27.4 %) had no significant influence on patient or graft survival (p > 0.05; log-rank). Hepatic artery thrombosis (13.2 %) had a significant influence on graft survival but not on patient survival (p = 0.002, >0.05, respectively; log-rank).

CONCLUSIONS

Split liver transplantation can be used safely and appears to be an underutilized resource that may benefit from liberal allocation of the second graft.

Hepatitis C disease severity in living versus deceased donor liver transplant recipients: an extended observation study

Donor factors influence hepatitis C virus (HCV) disease severity in liver transplant (LT) recipients. Living donors, because they are typically young and have short cold ischemic times, may be advantageous for HCV-infected patients. Among HCV-infected patients in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL) surviving >90 days and followed for a median 4.7 years, advanced fibrosis (Ishak stage ≥3) and graft loss were determined. The 5-year cumulative risk of advanced fibrosis was 44% and 37% in living donor LT (LDLT) and deceased donor LT (DDLT) patients (P = 0.16), respectively. Aspartate aminotransferase (AST) activity at LT (hazard ratio [HR] = 1.38 for doubling of AST, P = 0.005) and biliary strictures (HR = 2.68, P = 0.0001) were associated with advanced fibrosis, but LDLT was not (HR = 1.11, 95% confidence interval [CI] 0.73-1.69, P = 0.63). The 5-year unadjusted patient and graft survival probabilities were 79% and 78% in LDLT, and 77% and 75% in DDLT (P = 0.43 and 0.32), with 27% and 20% of LDLT and DDLT graft losses due to HCV (P = 0.45). Biliary strictures (HR = 2.25, P = 0.0006), creatinine at LT (HR = 1.74 for doubling of creatinine, P = 0.0004), and AST at LT (HR = 1.36 for doubling of AST, P = 0.004) were associated with graft loss, but LDLT was not (HR = 0.76, 95% CI: 0.49-1.18, P = 0.23).

CONCLUSION

Donor type does not affect the probability of advanced fibrosis or patient and graft survival in HCV-infected recipients. Thus, while LDLT offers the advantage of shorter wait times, there is no apparent benefit for HCV disease progression. Biliary strictures have a negative effect on HCV fibrosis severity and graft survival, and a high AST at LT may be an important predictor of fibrosis risk post-LT.

Ex vivo split-liver transplantation: the true right/left split

BACKGROUND

Successful left lateral segment (sectionectomy) and right trisegmentectomy (trisectionectomy) split-liver transplantation (SLT) have been achieved. However, there are few reports of the use of true right/left splitting in SLT.

METHODS

A single-centre retrospective review of true right/left ex vivo split-liver transplants performed during the period 1993-2010 was conducted. Nine cadaveric liver grafts underwent splitting and the resultant 18 allografts were used in transplants performed at the study centre.

RESULTS

In the nine right lobe recipients, 10-year patient and graft survival rates were both 74%. There were no vascular complications, one biliary complication and one re-exploration. In the nine left lobe recipients, 10-year patient and graft survival rates were 78% and 66%, respectively. Postoperative complications included six biliary complications, four of which required surgical revision and all of which occurred within 5 months of transplantation, and two vascular complications, including one early hepatic artery thrombosis (HAT) and one late HAT, one of which required retransplantation. Five left lobe recipients required re-exploration, and one patient developed small-for-size syndrome following SLT, which resolved with conservative measures.

CONCLUSIONS

True right/left ex vivo SLT remains a viable option for facilitating the expansion of the adult cadaver donor pool and allows for excellent patient and graft survival. Postoperative morbidity remains high, especially in recipients of the left lobe graft, and must be balanced with the benefits to be derived from transplant.

Cytokine concentrations and regulatory T cells in living donor and deceased donor liver transplant recipients

Outcomes of pediatric liver transplantation have constantly improved in the last decade. Living-related liver transplantation does not seem to improve long-term outcomes following liver transplantation, but few studies have evaluated immunological parameters of the alloimmune response after living vs. deceased donor organ transplantation. We analyzed numbers of regulatory T cells, lymphocyte subsets, and serum cytokine concentrations in 12 pediatric recipients of living-related liver transplants and in 28 pediatric recipients of deceased donor organs during their annual follow-ups. Transplant recipients who underwent living donor organ transplantation had significantly higher numbers of regulatory T cells and IL-4 serum concentrations than recipients of deceased donor organs; both of these factors are associated with beneficial outcomes and transplantation tolerance. Living-related liver transplantation may have potentially beneficial immunological aspects, although long-term outcomes do not seem to be better in recipients of living donor organs than in recipients of deceased donor organs. Further studies are needed to compare immunological aspects of the two transplant procedures.

Meeting report of the International Liver Transplantation Society's 18th annual international congress: Hilton San Francisco Hotel, San Francisco, CA, May 16-19, 2012

From May 16-19, 2012, the International Liver Transplantation Society held its annual congress in San Francisco, CA. More than 1300 registrants attended the meeting, which included a premeeting conference entitled Balancing Risk in Liver Transplantation, focused topic sessions, and a variety of oral and poster presentations. This report is not all-inclusive and focuses on specific research abstracts on key topics in liver transplantation. As always, the new data herein are presented in the context of the published literature to further enhance knowledge in the field.

Liver transplantation: issues and nursing care requirements

Liver transplantation has evolved into an accepted treatment for many suffering from end-stage liver failure. The complex nature of the liver results in every organ system being impacted by either the failing or the transplanted liver. Organ shortage remains problematic, and work to ensure maximizing the organ donor pool as well as the success of each organ transplant continues. The clinical care and condition of the patient before transplant can impact the outcome after transplant. Nurses can play an integral role in early identification of graft dysfunction, rejection, or infection. Because of the intimate and large amount of time that the nurse is at the patient’s bedside, he or she is often in a position to monitor for potential risks to the patient and take corrective action.

Where are we today in split liver transplantation?

PURPOSE OF REVIEW

Results of surgical innovations using partial liver grafts from deceased donors have improved the availability of transplantable organs. However, current data on outcomes after split liver transplantation (SLT) are conflicting. This article reviews the current state of SLT, focusing on long-term outcomes and predictors for patient and graft survival after SLT.

RECENT FINDINGS

The conventional SLT has been proven to be a durable life-saving procedure. Early results for full left-right SLT for two adults are promising but this technique had not showed efficacy for wide application. Predictors of diminished patient survival after SLT included the use of split grafts in critically ill recipients (model for end-stage liver disease score >30), retransplant patients, cold ischemia time more than 10 h, and the performance of SLT in low-volume liver transplant centers.

SUMMARY

Conventional SLT performed in specialized centers resulted in long-term survival outcomes comparable with whole-organ liver transplantation. Full left-right SLT for two adults remains experimental. Splitting of the liver is an effective approach to expand the donor pool and remains an untapped resource for patients in need of liver transplantation. Split graft-to-recipient pairing is crucial for optimal organ allocation and survival outcomes after liver transplantation.

Major challenges limiting liver transplantation in the United States

Liver transplantation is the gold standard of care in patients with end-stage liver disease and those with tumors of hepatic origin in the setting of liver dysfunction. From 1988 to 2009, liver transplantation in the United States grew 3.7-fold from 1713 to 6320 transplants annually. The expansion of liver transplantation is chiefly driven by scientific breakthroughs that have extended patient and graft survival well beyond those expected 50 years ago. The success of liver transplantation is now its primary obstacle, as the pool of donor livers fails to keep pace with the growing number of patients added to the national liver transplant waiting list. This review focuses on three major challenges facing liver transplantation in the United States and discusses new areas of investigation that address each issue: (1) the need for an expanded number of useable donor organs, (2) the need for improved therapies to treat recurrent hepatitis C after transplantation and (3) the need for improved detection, risk stratification based upon tumor biology and molecular inhibitors to combat hepatocellular carcinoma.

Outcomes in adult recipients of right-sided liver grafts in split-liver procedures

BACKGROUND

The split-liver technique provides a good left lateral graft in children, but its results in adults remain controversial.

METHODS

From 1992 to 2007, 37 patients received 38 cadaveric right-sided grafts. Donors and recipients were selected for good quality grafts and elective indications; the latter included a high proportion of tumour cases and primary sclerosing cholangitis. Grafts included 31 extended right grafts (ERGs; segments IV-VIII and I and the inferior vena cava [IVC]) and seven right grafts (RGs; segments V-VIII) including five without the IVC and middle hepatic vein (MHV).

RESULTS

Mortality was 5% (two patients). There were four retransplantations (11%) for arterial thrombosis (1), portal vein thrombosis (2) and primary non-function (1). The retransplantation rate was higher in RG than in ERG (three vs. one patient; P= 0.015). Of the five patients without MHV, three were retransplanted and one had small-for-size syndrome leading to late death. After a mean follow-up of 5 years, 1-, 3- and 5-year graft and patient survival rates were 84%, 80% and 71%, and 91%, 88% and 78%, respectively. One-year patient and graft survival rates after ERG transplantation were 96% and 92%, respectively.

CONCLUSIONS

Split-liver transplantation is a safe alternative to whole organ transplantation when an ERG is carried out. Right graft is associated with increased risk of graft loss, especially if the MHV is omitted. Split-liver transplantation with an ERG offers excellent outcomes and should be encouraged when good quality grafts are available.

Gender-specific differences associated with living donor liver transplantation: a review study

Living donor liver transplantation (LDLT) has developed into an important therapeutic option for liver diseases. For living donor kidney transplantation (LDKT), gender-specific differences have been observed among both donors (two-thirds being women and one-third being men) and recipients (two-thirds being men and one-third being women). The aim of this study was to determine whether there is a gender disparity for LDLT. We contacted 89 national and international transplantation registries, single transplant centers, and coordinators. In addition, a sample of 274 articles dealing with LDLT and its outcomes was reviewed and compared with the registry data. The data included the gender of the donors and recipients, the country of transplantation, and the donor-recipient relationship. The investigation showed that overall there were slightly more men among the donors (53% male and 47% female). As for the recipients, 59% of the organs were distributed to males, and 41% were distributed to females. Differences in the gender distribution were observed with respect to individual countries. Worldwide, 80% of the donors were blood-related, 11% were not blood-related, and 9% were spouses. The data acquired from the publications were similar to the registry data. Our research has shown that there are hardly any registry data published, a lot of countries do not have national registries, or the access to these data is difficult. Even widely ranging published studies often do not give information on the gender distribution or the donor-recipient relationship. Further investigations are needed to understand the possible medical, psychosocial, or cultural reasons for gender distribution in LDLT and the differences in comparison with LDKT.

Potential effect of using ABO-compatible living-donor liver transplantation

Liver transplantation increased 1.84-fold from 1988 to 2004. However, the number of patients on the waiting list for a liver increased 2.71-fold, from 553 to 1500. We used a mathematical equation to analyze the potential effect of using ABO-compatible living-donor liver transplantation (LDLT) on both our liver transplantation program and the waiting list. We calculated the prevalence distribution of blood groups (O, A, B, and AB) in the population and the probability of having a compatible parent or sibling for LDLT. The incidence of ABO compatibility in the overall population was as follows: A, 0.31; B, 0.133; O, 0.512; and AB, 0.04. The ABO compatibility for parent donors was blood group A, 0.174; B, 0.06; O, 0.152; and AB, 0.03; and for sibling donors was A, 0.121; B, 0.05; O, 0.354; and AB, 0.03. Use of LDLT can reduce the pressure on our liver transplantation waiting list by decreasing its size by at least 16.5% at 20 years after its introduction. Such a program could save an estimated 3600 lives over the same period.

Follow-up of Chinese liver transplant recipients in Hong Kong

The outcome of liver transplantation in China remains speculative. From 1998 to 2007, 177 adult Hong Kong patients underwent liver transplantation in China and were subsequently followed up at Queen Mary Hospital, Hong Kong. One hundred six (59.9%) patients had hepatocellular carcinoma (HCC). The grafts were probably derived from uncontrolled non-heart-beating donors. The 1-month mortality rate was 4.0%. The 1-, 3-, and 5-year overall survival rates were 73.9%, 59.0%, and 53.9%, respectively. The 5-year overall survival rates for non-HCC, HCC, HCC (within the Milan criteria), and HCC (beyond the Milan criteria) patients were 66.3%, 44%, 58%, and 26.2%, respectively. The long-term survival was compromised by the high incidence of HCC recurrence and graft failure secondary to diffuse intrahepatic biliary strictures. The overall survival rate of the entire group was lower than that of the patients receiving deceased donor liver grafts at Queen Mary Hospital in the same period. For non-HCC patients, however, the 5-year survival rate of 66.3% was comparable to that of recent reports from the Western world.

Longterm outcomes for whole and segmental liver grafts in adult and pediatric liver transplant recipients: a 10-year comparative analysis of 2,988 cases

BACKGROUND

Data on longterm outcomes after liver transplantation with partial grafts are limited. We compared 10-year outcomes for liver transplant patients who received whole grafts (WLT), split grafts from deceased donors (SLT), and partial grafts from living donors (LDLT).

STUDY DESIGN

We conducted a single-center analysis of 2,988 liver transplantations performed between August 1993 and May 2006 with median followup of 5 years. Graft types included 2,717 whole-liver, 181 split-liver, and 90 living-donor partial livers. Split-liver grafts included 109 left lateral and 72 extended right partial livers. Living-donor grafts included 49 left lateral and 41 right partial livers.

RESULTS

The 10-year patient survivals for WLT, SLT, and LDLT were 72%, 69%, and 83%, respectively (p=0.11), and those for graft survival were 62%, 55%, and 65%, respectively (p=0.088). There were differences in outcomes between adults and children when compared separately by graft types. In adults, 10-year patient survival was significantly lower for split extended right liver graft compared with adult whole liver and living-donor right liver graft (57% versus 72% versus 75%, respectively, p=0.03). Graft survival for adults was similar for all graft types. Retransplantation, recipient age older than 60 years, donor age older than 45 years, split extended right liver graft, and cold ischemia time>10 hours were predictors of diminished patient survival outcomes. In children, the 10-year patient and graft survivals were similar for all graft types.

CONCLUSIONS

Longterm graft survival rates in both adults and children for segmental grafts from deceased and living donors are comparable with those in whole organ liver transplantation. In adults, patient survival was lower for split compared with whole grafts when used in retransplantations and in critically ill recipients. Split graft-to-recipient matching is crucial for optimal organ allocation and best use of a scarce and precious resource.