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

Split liver transplantation in high MELD score adult recipients: a reappraisal

BACKGROUND

Split liver transplantation (SLT) from deceased donors is a potential solution to the global organ shortage. While effective in patients with mild disease, outcomes in high MELD score recipients remain uncertain and conflicting. This study compares survival in high vs. low MELD score recipients.

METHODS

This retrospective single-centre study included all consecutive patients transplanted with a split liver graft between 2010 and 2022. Two groups of recipients with MELD<25 and ≥ 25 at LT were compared.

RESULTS

The study population included 119 patients (n = 98 with MELD<25, n = 21 with MELD≥25) with an average follow-up of 55 months. Both groups were comparable in terms of indication for transplantation and donor characteristics. The high MELD group required more blood transfusions (7 vs. 3 units; p < 0.001) during LT and had a longer stay in intensive care unit (7 vs. 5 days; p = 0.011). Biliary, arterial, and venous complications were similar between groups, as well as graft survival (5 years: 75 % vs. 61 %, p = 0.35) and long-term overall survival (5 years: 83 % vs. 75 %, p = 0.17).

DISCUSSION

Our results indicate that SLT for patients with MELD≥25 improves access to grafts, is feasible and safe, without significant increased risk of severe complications or decreased long-term overall patient or graft survivals.

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.

The use of the T-tube in biliary tract reconstruction during orthotopic liver transplantation: An umbrella review

Biliary complications are one of the main concerns after liver transplantation, and to avoid these, the use of a T-tube has been advocated in biliary reconstruction. Most liver transplantation centres perform a biliary anastomosis without a T-tube to avoid the risk of complications and T-tube-related costs. Several meta-analyses have reached discordant conclusions regarding the benefits of using the T-tube. An umbrella review was performed to summarise quantitative measures about overall biliary complications, biliary leaks, biliary strictures and cholangitis associated with the T-tube use after liver transplantation. Published systematic reviews and meta-analyses related to the use of T-Tube in liver transplantation were searched and analysed. From the comprehensive literature search from PubMed, EMBASE and Cochrane Library databases on the 25th of October 2021, 104 records were retrieved. Seven meta-analyses and two systematic reviews were included in the final analysis. All the meta-analyses of RCT stated no differences in overall biliary complications and biliary leaks when using T-tube for a liver transplant (I2 ≥ 90% and I2 range 0-76%, respectively). The meta-analysis of the RCTs evaluating the risks of biliary strictures after liver transplantation showed that T-tube protects from the complication (I2 range 0-80%). Biliary anastomosis without a T-tube has equivalent overall biliary complications and bile leaks compared to the T-tube reconstruction. The incidence of biliary strictures is attenuated in patients with T-tubes, and most meta-analyses of RCTs have very low heterogeneity. Therefore, the present umbrella review suggests a selective T-tube use, particularly in small biliary ducts or transplants with marginal grafts at high risk of post-LT strictures.

Are split liver grafts a suitable option in high-risk liver transplant recipients?

PURPOSE OF REVIEW

To assess the outcomes of split liver transplantation (SLT) in adults and children and evaluate its role in high-risk recipients with a high model for end-stage liver disease (MELD) score, an urgent indication or requiring retransplantation.

RECENT FINDINGS

Split liver grafts in general have equivalent long-term survival outcomes to whole grafts despite an increase in biliary complications. Recent success and technical advances have encouraged use of these grafts in high-risk recipients. Split liver grafts can be used successfully in recipients with a high MELD score if there is adequate weight-matching. There are mixed results in urgent indication recipients and for retransplantation such that use in this group of patients remains controversial.

SUMMARY

SLT addresses donor shortages by facilitating the transplant of two recipients from the same donor liver. By using careful donor and recipient selection criteria, SLT can achieve equivalent long-term outcomes to whole grafts. These grafts have been used successfully in recipients with a high MELD score, but should be used selectively in urgent indication recipients and for retransplantation.

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.

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.

Feasibility and Safety of Split-Liver Transplantation in a Nascent Framework of Deceased Donation

Split-liver transplantation (SLT) is a valuable option for optimizing the use of good-quality deceased donor grafts. It is not routinely reported outside the West because of limited deceased donor numbers, technical and organizational constraints, lack of experience, and a predominant living donor liver transplantation (LDLT) practice. At our center, 20% of the liver transplantations (LTs) are from deceased donors. We report our experience of SLT and compare outcomes with pediatric and adult LDLT recipients. A prospectively maintained database of all LT recipients between September 2009 and March 2017 was analyzed. Each pediatric SLT recipient was matched to 2 pediatric LDLT recipients for age, weight, urgency, and year of transplant. Each adult SLT recipient was similarly matched to 2 adult LDLT recipients for age, Model for End-Stage Liver Disease score, and year of transplant. Intraoperative and postoperative parameters, including recovery time, morbidity (biliary and vascular complications, Clavien grade >IIIA complications), and mortality were compared. In total, 40 SLTs were performed after splitting 20 deceased donor livers (in situ, n = 11; hybrid split, n = 3; and ex vivo, n = 6). Recipients included 22 children and 18 adults. There were 18 livers that were split conventionally (extended right lobe and left lateral segment [LLS]), and 2 were right lobe-left lobe SLTs. Also, 3 LLS grafts were used as auxiliary grafts for metabolic liver disease. Perioperative mortality in SLT recipients occurred in 3 patients (2 children and 1 adult). Incidence of vascular, biliary, and Clavien grade >IIIA complications were similar between matched adult and pediatric SLT and LDLT groups. In conclusion, SLT is an effective technique with outcomes comparable to living donor grafts for adult and pediatric recipients. Using SLT techniques at centers with limited deceased donors optimizes the use of good-quality whole grafts and reduces the gap between organ demand and availability.

Improving graft survival by understanding the mechanism of segment 4 complications after split liver transplantation

BACKGROUND

This study was designed to assess the actual mechanism of segment 4 (S4)-related complications after split liver transplantation (SLT) and their impact on graft and overall survival with reference to those of left lateral sectionectomy for pediatric living donor liver transplantation (LLSLD).

METHODS

Clinical data from 53 SLT recipients and 62 LLSLD patients were assessed to determine the mechanism of S4-related complications. The postoperative parameters of SLT and their impact on graft and overall survival were also evaluated.

RESULTS

Although two biliary leakages were noted (3.2%), no necrosis of S4 developed after LLSLD. S4-related complications were seen in 15 (28.3%) patients after SLT. Radiological volumetry of S4 and the ischemic area after SLT showed no significant difference between those with and without S4-related complications. There were no significant differences between the patients with and without S4-related complications regarding both overall and graft survival rates. Significant better overall and graft survival rates were observed in patients treated during the later period.

CONCLUSIONS

S4-related complications after SLT are totally independent of the S4 volume, and biliary leakage is inherently an actual mechanism. Adequate intervention with early identification leads to better graft and overall survival, which validates SLT as a treatment option.

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.

Fifteen years and 382 extended right grafts from in situ split livers in a multicenter study: Are these still extended criteria liver grafts?

In situ split liver extended right grafts (SL-ERGs) are still considered marginal grafts. Our aim was to verify this statement at the present time. From 1997 to 2011, a multicenter, retrospective study based on a prospective database was performed at 9 liver transplantation (LT) centers in northern Italy; it included 382 in situ SL-ERG transplants in adults. There were 358 primary LTs and 24 retransplantations (RETXs). The 1-, 3-, and 5-year overall graft survival rate for LT with in situ SL-ERGs were 73.5%, 63.3%, and 60.7%, respectively, from 1997 to 2004 and 83.5%, 80.3%, and 80.3%, respectively, thereafter (P=0.0001). A shorter total ischemia time and fewer RETX grafts were the main differences between the characteristics of the 2 periods. From 1997 to 2011, the 1-, 3-, and 5-year graft survival rates showed a significant difference between the 358 primary LT in situ SL-ERGs and the 24 RETX in situ SL-ERGs (P<0.001). In a multivariate analysis, the main prognostic factor for 60-day graft survival was a total ischemia time<8 hours for the 358 primary in situ SL-ERGs. From 2005 to 2011, in 2473 LTs, the 5-year graft survival for 184 in situ SL-ERGs and 2289 whole grafts was 75% and 80% (P=0.3), respectively. Univariate and multivariate studies alike failed to indicate that the type of graft was a prognostic factor for graft survival. A donor age>60 years, RETX grafts, and urgency were the main prognostic factors for failure for all of the grafts. Although caution should be taken regarding the choice of appropriate donors, in situ SL-ERGs should no longer be considered marginal grafts for experienced LT centers. SL-ERGs should not be used in RETX settings, and when SL-ERGs are used as primary grafts, the total ischemia time should be less than 8 hours.

Split liver transplantation using Hemiliver graft in the MELD era: a single center experience in the United States

Under the "sickest first" Model for End-Stage Liver Disease (MELD) allocation, livers amenable to splitting are most often allocated to patients unsuitable for split liver transplantation (SLT). Our experience with SLT using hemilivers was reviewed. From April 2004 to June 2012, we used 25 lobar grafts (10 left lobes and 15 right lobes) for adult-sized recipients. Twelve recipients were transplanted with primary offers, and 13 were transplanted with leftover grafts. Six grafts were shared with other centers. The data were compared with matched whole liver grafts (n = 121). In 92% of donors, the livers were split in situ. Hemiliver recipients with severe portal hypertension had a greater graft-to-recipient weight ratio than those without severe portal hypertension (1.96% vs. 1.40%, p < 0.05). Hemiliver recipients experienced biliary complications more frequently (32.0% vs. 10.7%, p = 0.01); however, the 5-year graft survival for hemilivers was comparable to whole livers (80.0% vs. 81.5%, p = 0.43). The secondary recipients with leftover grafts did not have increased incidences of graft failure (p = 0.99) or surgical complications (p = 0.43) compared to the primary recipients. In conclusion, while routine application is still controversial due to various challenges, hemiliver SLT can achieve excellent outcomes under the MELD allocation.

Trends in liver transplantation 2011

This review will highlight some of the important recent trends in liver transplantation. When possible, we will compare and contrast these trends across various regions of the world, in an effort to improve global consensus and better recognition of emerging data.