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.

Quantifying the Disadvantage of Small Recipient Size on the Liver Transplantation Waitlist, a Longitudinal Analysis Within the Eurotransplant Region

BACKGROUND

Small adult patients with end-stage liver disease waitlisted for liver transplantation may face a shortage of size-matched liver grafts. This may result in longer waiting times, increased waitlist removal, and waitlist mortality. This study aims to assess access to transplantation in transplant candidates with below-average bodyweight throughout the Eurotransplant region.

METHODS

Patients above 16 y of age listed for liver transplantation between 2010 and 2015 within the Eurotransplant region were eligible for inclusion. The effect of bodyweight on chances of receiving a liver graft was studied in a Cox model corrected for lab-Model for End-stage Liver Disease (MELD) score updates fitted as time-dependent variable, blood type, listing for malignant disease, and age. A natural spline with 3 degrees of freedom was used for bodyweight and lab-MELD score to correct for nonlinear effects.

RESULTS

At the end of follow-up, the percentage of transplanted, delisted, and deceased waitlisted patients was 49.1%, 17.9%, and 24.3% for patients with a bodyweight <60 kg (n = 1267) versus 60.1%, 15.1%, and 18.6% for patients with a bodyweight ≥60 kg (n = 10 520). To reach comparable chances for transplantation, 60-kg and 50-kg transplant candidates are estimated to need, respectively, up to 2.8 and 4.0 more lab-MELD points than 80-kg transplant candidates.

CONCLUSIONS

Decreasing bodyweight was significantly associated with decreased chances to receive a liver graft. This resulted in substantially longer waiting times, higher delisting rates, and higher waitlist mortality for patients with a bodyweight <60 kg.

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.

Revisiting the forgotten "full-right full-left" liver division: Simplified technique and new strategical considerations for clinical implementation in Italy

BACKGROUND

Full-right/full-left liver splitting was introduced early in the 90s as part of the great wave of technical innovations that characterized that decade. One approach was to divide the liver on the right of the Cantlie's line and leave the middle hepatic vein with the left graft, with both grafts allocated to adults. Both grafts had some functional disadvantages and exposed the adult recipients to some early hepatic dysfunction, and the results were not great. An alternative approach consisted of an ex situ division of the liver, exactly along Cantlie's line, thus sharing the middle hepatic vein between the two grafts. None of these two techniques were really adopted, and there has been nearly no transplantation of this type in the last decade worldwide.

METHOD AND RESULTS

The authors propose a variation of the latter technique that was used recently with success: The division of the liver is made simpler; the two grafts are prepared ex situ and need a simple vascular reconstruction (one venous patch on each graft); and the grafts can be implanted using very standard techniques.

CONCLUSION

Because candidates for liver transplantation weighing 25-60 kg (old children, teenagers, and some small adults) are often at some disadvantage in getting size-matched livers (this range of weight is less represented in the donor population), implementing the latter technique would help provide adequate grafts for them. In Italy, where many livers offered for splitting are not used, there would be ample room for implementing this option within the actual donor pool and allocation system.

Full-Right Full-Left Split Liver Transplantation for Two Adult Recipients: A Single-Center Experience in China

BACKGROUND

The most effective treatment for end-stage liver diseases is liver transplantation, which is impeded by the shortage of donor livers. Split liver transplantation (SLT) is important for addressing the donor liver shortage. However, full-right full-left SLT for two adult recipients is globally rarely conducted. This study aimed to investigate the clinical outcomes of this technique.

METHODS

We retrospectively analyzed the clinical data of 22 recipients who underwent full-right full-left SLT at Shulan (Hangzhou) Hospital between January, 2021 and September, 2022. The graft-to-recipient weight ratio (GRWR), cold ischemia time, operation time, length of the anhepatic phase, intraoperative blood loss, and red blood cell transfusion amount were all analyzed. The differences in liver function recovery after transplantation were compared between the left and right hemiliver groups. The postoperative complications and prognosis of the recipients were also analyzed.

RESULTS

The livers of 11 donors were transplanted into 22 adult recipients. The GRWR ranged from 1.16-1.65%, the cold ischemia time was 282.86 ± 134.87 min, the operation time was 371.32 ± 75.36 min, the anhepatic phase lasted 60.73 ± 19.00 min, the intraoperative blood loss was 759.09 ± 316.84 mL, and the red blood cell transfusion amount was 695.45 ± 393.67 mL. No significant difference in the levels of liver function markers, total bilirubin, aspartate aminotransferase, or alanine aminotransferase between left and right hemiliver groups at 1, 3, 5, 7, 14, and 28 d postoperatively was observed (both p > 0.05). One recipient developed bile leakage 10 d after transplantation, which improved with endoscopic retrograde cholangiopancreatography-guided nasobiliary drainage and stent placement. Another developed portal vein thrombosis 12 d after transplantation and underwent portal vein thrombectomy and stenting to restore portal vein blood flow. A color Doppler ultrasound performed 2 d after transplantation revealed hepatic artery thrombosis in one patient, and thrombolytic therapy was administered to restore hepatic artery blood flow. The liver function of other patients recovered quickly after transplantation.

CONCLUSIONS

Full-right full-left SLT for two adult patients is an efficient way to increase the donor pool. It is safe and feasible with careful donor and recipient selection. Transplant hospitals with highly experienced surgeons in SLT are recommended to promote using full-right full-left SLT for two adult recipients.

Declined Organs for Liver Transplantation: A Right Decision or a Missed Opportunity for Patients with Hepatocellular Carcinoma?

BACKGROUND

Liver transplantation is the only promising treatment for end-stage liver disease and patients with hepatocellular carcinoma. However, too many organs are rejected for transplantation.

METHODS

We analyzed the factors involved in organ allocation in our transplant center and reviewed all livers that were declined for transplantation. Reasons for declining organs for transplantation were categorized as major extended donor criteria (maEDC), size mismatch and vascular problems, medical reasons and risk of disease transmission, and other reasons. The fate of the declined organs was analyzed.

RESULTS

1086 declined organs were offered 1200 times. A total of 31% of the livers were declined because of maEDC, 35.5% because of size mismatch and vascular problems, 15.8% because of medical reasons and risk of disease transmission, and 20.7% because of other reasons. A total of 40% of the declined organs were allocated and transplanted. A total of 50% of the organs were completely discarded, and significantly more of these grafts had maEDC than grafts that were eventually allocated (37.5% vs. 17.7%, p < 0.001).

CONCLUSION

Most organs were declined because of poor organ quality. Donor-recipient matching at time of allocation and organ preservation must be improved by allocating maEDC grafts using individualized algorithms that avoid high-risk donor-recipient combinations and unnecessary organ declination.

Outcome of Extended Right Lobe Liver Transplantations

Split-liver transplantation offers a solution to the organ shortage problem. However, the outcomes of extended right lobe liver transplantation (ERLT) and whether it is a suitable alternative to full-size liver transplantation (FSLT) remain controversial. We compared the outcomes of ERLT and FSLT in adult recipients of 43,409 first deceased donor liver transplantations using Cox regression. We also analyzed 612 ERLT and 1224 FSLT 1:2 matched cases to identify factors that affect ERLT outcome. The risk of graft loss was significantly higher following ERLT than following FSLT during the first posttransplantation year in the matched and unmatched collective (hazard ratio [HR], 1.39 and 1.27 and P = 0.01 and 0.006, respectively). Every additional hour of cold ischemia time (CIT) increased the risk of 1-year graft loss by 10% in the ERLT group compared with only 3% in the FSLT group (P = 0.003 and <0.001, respectively). Importantly, the outcome of ERLT and FSLT did not differ significantly if the CIT was below 10 hours (HR, 0.71; P = 0.22). One-year graft and patient survival were lower in high-risk ERLT recipients with a Model for End-Stage Liver Disease (MELD) score of ≥20 (HR, 1.88; P = 0.03 and HR, 2.03; P = 0.02). In the male recipient-male donor combination, ERLT recipients had a higher risk of 1-year graft loss than FSLT recipients (HR, 2.44; P = 0.006). This was probably because of the significantly higher MELD score in ERLT recipients (P = 0.004). ERLT in adults is an adequate alternative to FSLT and offers an elegant solution to the problem of organ shortage as long as the cold storage is less than 10 hours and the recipient's MELD score is <20.

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.

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.

Adult split liver transplantation: A PRISMA-compliant Chinese single-center retrospective case-control study

Although pediatric split liver transplantation (SLT) has been proven safe and the waitlist mortality rate has been successfully reduced, the safety of adult SLT has not been confirmed.Using 1:2 matching, 47 recipients who underwent adult SLT were matched to 94 of 743 recipients who underwent adult whole graft liver transplantation (WGLT). Eventually, 141 recipients were included in the case-control study. Subgroup analysis of 43 recipients in the SLT group was performed based on the presence of the middle hepatic vein (MHV) in the grafts.No significant differences in 5-year survival (80.8% vs 81.6%, P = .465) were observed between the adult SLT and WGLT groups. However, compared to recipients in the WGLT group, those in the SLT group had more Clavien-Dindo grade III-V complications, longer hospitalization duration, and higher mortality within 45 days. Furthermore, on multivariate analysis, 45-day postoperative mortality in recipients in the SLT group was mainly affected by hyperbilirubinemia within postoperative day (POD) 7-14, surgery time, and intraoperative blood loss. Subgroup analysis showed no significant differences in hyperbilirubinemia within POD 7-14, complications, and survival rate between SLTMHV(+) and SLTMHV [-].Adult SLT is safe and effective based on long-term survival rates; however, a reduction in the incidence of short-term complications is required. Non-obstructive hyperbilirubinemia within POD 7 to 14 is an independent predictor of short-term mortality after SLT.

Split liver transplantation: a single center experience

Background: Split liver transplantation is used worldwide and allows for an increase of donor organ pool, especially for pediatric recipients. Donor selection, some aspects of surgical techniques and long-term results remain to be important issues of split liver transplantation.

Aim: To analyze our own clinical results of split liver transplantation, basic principles of deceased donor selection and specifics of surgical technique.

Materials and methods: From May 2008 to December 2019, 32 cases of division of the deceased donor liver for transplantation to two recipients have been performed (64 split liver transplantations). Liver was divided into the left lateral section and the extended right lobe in 30 cases (“classical split”), and into the left lobe and right lobe in two cases (“full-split”). In 22 cases, the liver grafts were split in situ and in 10, ex-situ.

Results: In the recipients of left-side transplants (left lateral section and whole left lobe), the one-, three-, and five-year survival rates were 80, 80, and 60%, respectively. In the right-sided transplant recipients (extended right lobe and right lobe), the one-, three-, and five-year survival rates were 93.3, 89.4, and 89.4%, respectively (p = 0.167). The most probable risk factors for mortality in the univariate analysis were liver retransplantation (p = 0.047) and patient’s weight (p = 0.04).

Conclusion: For split transplantation, it is advisable to consider donors with a high-quality liver. This technique demonstrates satisfactory results and can be viewed as effective for patients with terminal liver diseases.

Disadvantage of Small (<60 kg) Adult Candidates on the Liver Transplantation Waitlist

BACKGROUND

Small adult patients with lower bodyweight wait-listed for liver transplantation may face a shortage of size-matched whole-liver grafts. The objective of this study is to compare time to transplantation in adult patients with a bodyweight of <60 kg to patients with bodyweight ≥60 kg.

METHODS

A matched case-control study was conducted. Patients aged 18 years and older listed for liver transplantation at our transplant center, from 2007 to 2016 with a bodyweight <60 kg were manually matched 1:2 to control patients ≥ 60 kg. Matching was performed based on ABO blood type, model for end-stage liver disease score, (non)-standard exception status, and eligibility for donation after cardiac death. Time to transplantation was assessed with univariable Cox-regression.

RESULTS

In total, 23 cases with a bodyweight < 60 kg were matched to 46 average-sized control patients. Small adults were significantly disadvantaged for receiving a liver transplantation as compared to their average-sized counterpart (hazard ratio 0.47; 95% confidence interval 0.29-0.75, P = .002). At the end of follow-up, 14/23 (60.9%) of cases versus 35/46 of controls (76.1%) had received a liver transplantation.

CONCLUSION

Small adults with a bodyweight below 60 kg are disadvantaged on the waitlist for a size-matched whole liver graft.

Outcome after pediatric liver transplantation for staged abdominal wall closure with use of biological mesh-Study with long-term follow-up

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft-to-recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end-point was the occurrence of postoperative abdominal wall infection. Secondary end-points included 1- and 5-year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no-BM group. No significant differences between the two groups were observed for 1- and 5-year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no-BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.

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.

A national mandatory-split liver policy: A report from the Italian experience

To implement split liver transplantation (SLT) a mandatory-split policy has been adopted in Italy since August 2015: donors aged 18-50 years at standard risk are offered for SLT, resulting in a left-lateral segment (LLS) graft for children and an extended-right graft (ERG) for adults. We aim to analyze the impact of the new mandatory-split policy on liver transplantation (LT)-waiting list and SLT outcomes, compared to old allocation policy. Between August 2015 and December 2016 out of 413 potentially "splittable" donors, 252 (61%) were proposed for SLT, of whom 53 (21%) donors were accepted for SLT whereas 101 (40.1%) were excluded because of donor characteristics and 98 (38.9%) for absence of suitable pediatric recipients. The SLT rate augmented from 6% to 8.4%. Children undergoing SLT increased from 49.3% to 65.8% (P = .009) and the pediatric LT-waiting list time dropped (229 [10-2121] vs 80 [12-2503] days [P = .045]). The pediatric (4.5% vs 2.5% [P = .398]) and adult (9.7% to 5.2% [P < .001]) LT-waiting list mortality reduced; SLT outcomes remained stable. Retransplantation (HR = 2.641, P = .035) and recipient weight >20 kg (HR = 5.113, P = .048) in LLS, and ischemic time >8 hours (HR = 2.475, P = .048) in ERG were identified as predictors of graft failure. A national mandatory-split policy maximizes the SLT donor resources, whose selection criteria can be safely expanded, providing favorable impact on the pediatric LT-waiting list and priority for adult sick LT candidates.