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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.

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.

Right lobe split liver graft versus whole liver transplantation: A systematic review by updated traditional and cumulative meta-analysis

INTRODUCTION

Advancements in surgical techniques and experience of donor-recipient pairing has led to a wider use of right split liver grafts in adults. An update meta-analysis was conducted to compare right split liver graft (RSLG) and whole liver transplantation (WLT) using traditional and cumulative approaches.

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 and graft survival were obtained using the inverse variance hazard ratio method.

RESULTS

Donors were significantly younger in the RSLG group than in the WLT group (MD = -12.06 [-16.29 to -7.83]; P < .001). In addition, the model for end-stage liver disease (MELD) score was significantly lower in the RSLG group than in the WLT group (MD = -2.45 [-4.61 to -.28]; P = .03). However, cold ischaemia time was significantly longer by 1 h in the RSLG group than in the WLT group (MD = 57 [20.63-92.73]; P = .002). Overall biliary, vascular, and outflow tract complications and hepatic artery thrombosis were significantly lower in the WLT group than in the RSLG group (odds ratio [OR] = 1.75 [1.35-2.27], P < .001; OR = 1.91 [1.37-2.65], P = .006; Peto OR = 1.83 [1.19-2.82], P = .006; and Peto OR = 2.07 [1.39-3.10], P = .004, respectively). However, no difference in patient and graft survival was noted between the two cohorts.

CONCLUSIONS

Although the RSLG group had a higher postoperative complication rate than the WLT group, equal patient and graft survival benefits were observed.

Current status and perspectives in split liver transplantation

Growing experience with the liver splitting technique and favorable results equivalent to those of whole liver transplant have led to wider application of split liver transplantation (SLT) for adult and pediatric recipients in the last decade. Conversely, SLT for two adult recipients remains a challenging surgical procedure and outcomes have yet to improve. Differences in organ shortages together with religious and ethical issues related to cadaveric organ donation have had an impact on the worldwide distribution of SLT. Despite technical refinements and a better understanding of the complex liver anatomy, SLT remains a technically and logistically demanding surgical procedure. This article reviews the surgical and clinical advances in this field of liver transplantation focusing on the role of SLT and the issues that may lead a further expansion of this complex surgical procedure.

Right lobe split liver transplantation versus whole liver transplantation in adult recipients: A systematic review and meta-analysis

Split liver transplantation (SLT) has proven to be an effective technique to reduce the mortality of children on the waiting list, but whether creating 2 split grafts from 1 standard-criteria whole liver would compromise outcomes of adult recipients remains uncertain. We conducted this meta-analysis to compare outcomes of right lobe SLT and whole liver transplantation (WLT) in adult patients. PubMed, Embase, and the Cochrane Library were searched for relevant articles published before December 2014. Outcomes assessed were patient survival (PS), graft survival (GS), and major surgical complications after transplantation. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to synthesize the results. Seventeen studies with a total of 48,457 patients met the full inclusion criteria. PS and GS rates were all found to be equivalent between SLT and WLT recipients. However, SLT was associated with higher rates of overall biliary complications (OR = 1.66; 95% CI = 1.29-2.15; P < 0.001), bile leaks (OR = 4.30; 95% CI = 2.97-6.23; P < 0.001), overall vascular complications (OR = 1.81; 95% CI = 1.29-2.53; P < 0.001), hepatic artery thromboses (OR = 1.71; 95% CI = 1.17-2.50; P = 0.005), and outflow tract obstructions (OR = 4.17; 95% CI = 1.75-9.94; P = 0.001). No significant difference was observed in incidences of biliary stricture, portal vein complications, postoperative bleeding requiring surgical treatments, primary nonfunction, and retransplantations. In subgroup analyses, biliary and vascular complications only increased after ex vivo SLT rather than in situ SLT, and SLT recipients had more retransplantations if they matched with WLT recipients in terms of urgent status. In conclusion, adult right lobe SLT was associated with increased biliary and vascular complications compared with WLT, but it did not show significant inferiority in PSs and GSs.

Conventional split liver transplantation for two adult recipients: a recent experience in a single European center

BACKGROUND

Split liver transplantation (SLT) for two adult recipients is still considered a challenging procedure, especially when subjected to model for end-stage liver disease (MELD)-based allocation criteria.

METHODS

Twenty-two SLTs were performed in adult recipients in a European center operating within a MELD-oriented system. Thirteen right-sided grafts and nine left-sided grafts were used. Right-sided grafts included 11 extended right grafts and two full right grafts. Left-sided grafts included six left lateral segment grafts and three full left grafts. Ninety-three percent of donors were allocated based on MELD score. Median graft-to-recipient body weight ratio was 1.53 (range 1.07-2.11) with right-sided grafts and 0.81 (range 0.67-1.11) with left-sided grafts. Liver cirrhosis (46%) and metabolic/genetic disorders (56%) were the main indications for transplant in recipients of right and left grafts, respectively.

RESULTS

Overall patient and graft survival were 90% and 86%. Patient survival was 84% in recipients of right grafts and 100% in recipients of left grafts. Graft survival was 84% and 89%, respectively. Vascular and biliary complications occurred in 14% and 4% of cases. Postoperative serum levels of total bilirubin were significantly higher in recipients of left-sided grafts versus right-sided grafts on postoperative days 7 and 14. Prothrombin activity was significantly lower in recipients of left-sided grafts versus right-sided grafts on postoperative days 3 and 7.

CONCLUSIONS

SLT for two adult recipients can be successfully performed even using left lateral segments by assigning one graft according to MELD score, and with a more liberal allocation of the second graft.

Split-liver transplantation: an underused resource in liver transplantation

Split-liver transplantation is an efficient tool to increase the number of liver grafts available for transplantation. More than 15 years after its introduction only the classical splitting technique has reached broad application. Consequently children are benefiting most from this possibility. Full-right full-left splitting for two adult recipients has been shown to work but is hampered mainly by the dangers of small-for-size transplantation. A solution to this last problem would completely change the scope of split-liver transplantation. Organ allocation systems and collaboration between centers play a crucial role in the chances to let suitable patients profit from this valuable source of extra grafts.