Deceased-donor split-liver transplantation in adult recipients: is the learning curve over?

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.

Technical Variant Liver Transplant Utilization for Pediatric Recipients: Equal Graft Survival to Whole Liver Transplants and Promotion of Timely Transplantation Only When Performed at High-volume Centers

BACKGROUND

Technical variant liver transplantation (TVLT) is a strategy to mitigate persistent pediatric waitlist mortality in the United States, although its implementation remains stagnant. This study investigated the relationship between TVLT utilization, transplant center volume, and graft survival.

METHODS

Pediatric liver transplant recipients from 2010 to 2020 (n = 5208) were analyzed using the Scientific Registry of Transplant Recipients database. Transplant centers were categorized according to the average number of pediatric liver transplants performed per year (high-volume, ≥5; low-volume, <5). Graft survival rates were compared using Kaplan-Meier curves and log-rank tests. Cox proportional hazards models were used to identify predictors of graft failure.

RESULTS

High-volume centers demonstrated equivalent whole liver transplant and TVLT graft survival ( P = 0.057) and significantly improved TVLT graft survival compared with low-volume centers ( P < 0.001). Transplantation at a low-volume center was significantly associated with graft failure (adjusted hazard ratio, 1.6; 95% confidence interval, 1.14-2.24; P = 0.007 in patients <12 y old and 1.8; 95% confidence interval, 1.13-2.87; P = 0.013 in patients ≥12 y old). A subset of high-volume centers with a significantly higher rate of TVLT use demonstrated a 23% reduction in waitlist mortality.

CONCLUSIONS

Prompt transplantation with increased TVLT utilization at high-volume centers may reduce pediatric waitlist mortality without compromising graft survival.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT AND IMPLICATIONS

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

Split or whole liver transplantation? Utilization and posttransplant survival

BACKGROUND

Split liver transplantation (SLT), where a single donor liver is divided for transplantation to 2 recipients, has the potential to increase the availability of size-matched livers for pediatric candidates and expand the supply of donor organs available for adult candidates. Although SLT is a well-established technique, the number of SLTs has remained flat during the past 2 decades, partly due to concerns about the posttransplant survival of SLT recipients compared with whole liver transplantation (WLT) recipients. Prior work on SLT versus WLT survival analysis had limitations because, for pediatric recipients, it did not consider the correlations between donor age/weight and the allograft type, and for adult recipients, it may have included records where the donor livers did not meet the split liver criteria (splittable).

METHODS

Using the Organ Procurement and Transplantation Network's database (2003-2019), this study analyzes and compares (i) key characteristics of donors and recipients, (ii) donor-recipient match dynamics (organ offers and accept/decline decisions), and (iii) recipient posttransplant survival, for SLT and WLT.

RESULTS AND CONCLUSIONS

The results in this study show that the posttransplant survival of SLT and WLT recipients is similar (controlling for other confounding factors that may impact posttransplant survival), highlighting the importance of SLT for increasing the liver supply and potential benefits for both pediatric and adult candidates.

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.

Impact of donor age on short-term outcomes after pediatric split liver transplantation

Background

Donor shortage is an important limitation of liver transplantation (LT). Split liver transplantation (SLT) may increase the sources of donors and reduce the problem of organ shortage. However, there are no standard criteria of the selection of SLT donor, especially regarding the donor age.

Methods

We retrospectively analyzed the clinical data of children who received initial SLT between January 2015 and December 2021. Based on the age of donors, the patients were divided into groups A (1-10 years old; n = 26), B (10-45 years old; n = 87), and C (45-55 years old; n = 27). The short-term (<1 year after SLT) outcomes of the recipients were analyzed.

Results

A total of 140 patients received SLT from 122 donors. The 1-, 3- and 12-month patient survival rates in group A were 100.0%, and the graft survival rates were 92.3%. The 1-, 3- and 12-month survival rates of patient and graft in group B were 97.7%, 96.6%, and 95.0%, respectively, and in group C were 85.2%, 85.2%, and 81.1%, respectively. The patient survival rate was significantly lower in group C than in groups A and B (p = 0.0082). There was no significant difference in graft survival between the three groups (p = 0.0545).

Conclusions

Similar results were obtained for pediatric SLT with donors <10 years old and 10-45 years old. Pediatric SLT can be performed with older donors (45-55 years) after strict donor selection and selection of appropriate recipients.

Increased use of split liver grafts in adult recipients following implementation of a pediatric liver transplant program

BACKGROUND

Split liver transplantation (SLT) is a strategy to address organ shortage, but is a technically more demanding procedure than whole graft liver transplantation (LT). We aimed to determine the outcomes following SLT in adult recipients as well as to highlight the impact that having a pediatric LT program has on SLT implementation.

METHODS

All SLTs conducted at a single-center from 2010 to 2019 were identified. Patient data was obtained through retrospective review of the electronic medical record. Kaplan-Meier analysis assessed primary outcomes of 1-,3-, and 5-year graft and patient survival.

RESULTS

We identified 37 SLTs performed at our institution from 2010 to 2019. Twenty-four donated livers resulted in 21 extended right lobes and 16 left lateral segments for adults and pediatrics recipients, respectively. Eighty-one percent (30/37) of the SLTs were performed after introduction of the combined pediatric program in 2016. 13/24 donor livers were split with both grafts allocated and used at our institution and 92% occurred after introduction of the pediatric program. Graft survival rates at 1-, 3-, and 5-years were 94% in adult recipients and 100% for all time periods in pediatric recipients. Actuarial post-transplant patient survival was 100% at 1-, 3-, and 5-years in both.

CONCLUSIONS

The introduction of a pediatric liver transplantation program resulted in more than a fourfold increase in the number of SLTs performed at our center. Increase in allocation and use of both grafts at our institution was also seen.

Split liver transplantation with extended right grafts on adult recipients: A propensity score matching analysis

INTRODUCTION

Split liver transplantation (SLT) emerged due to its potential to contribute to the organ pool and reduce organ shortage. However, SLT is technically challenging and has been associated with higher rates of postoperative complications leading to concerns about graft and patient survival. Moreover, there are few studies on matched-pair adult recipients of SLT and whole-liver transplant (WLT), with conflicting results.

METHODS

This retrospective study analyze outcomes among adults who underwent SLT at our institution from 2010 to 2019. A 1:1 propensity score matching analysis was performed based on important donor and recipient variables. Baseline characteristics and postoperative outcomes were analyzed and compared between groups. Actuarial graft and patient survival were analyzed by KM curves.

RESULTS

Out of 592 adults receiving a LT in our institution, 21 SLT adult recipients were identified and matched with 21 adults undergoing WLT. As expected donor age was significantly lower in SLT recipients (16 (15-22) vs. 32 (17-47), P = .012). Additional donor characteristics, including anthropometrics, and ischemic times were similar between groups. Baseline recipient characteristics and postoperative outcomes, including length of stay, vascular complications, biliary complications, and re-transplantation were comparable between SLT and WLT recipients. Graft (95/95/95 vs. 100/94/94, P = .98) and patient (100/100/100 vs. 100/94/94, P = .30) survival at 1-, 3-, 5-years, were similar between the SLT- and WLT group, respectively.

CONCLUSION

Split liver transplantation has the potential to increase the availability of organs for adult recipients without compromising individual outcomes.

IV segment portal vein reconstruction in split-liver transplantation with extended right grafts

Background

Liver transplantation is one of the most effective treatments for end-stage liver disease. Split liver transplantation (SLT) can effectively improve the utilization efficiency of grafts. However, split liver transplantation still faces shortcomings and is not widely used in surgery. How to improve the effective transplantation volume of split liver transplantation and promote the postoperative recovery of patients has important clinical significance.

Methods

In our study, the donor’s liver was split into the extended right graft and left lateral sector, and the IV segment occur ischemia. To guarantee the functional graft size, and avoid complications, we reconstructed the IV segment portal vein and left portal vein. And we analyzed the operation time, intraoperative bleeding, liver function, and postoperative complications.

Results

In our research, 14 patients underwent IV segment portal vein reconstruction, and 8 patients did not undergo vascular reconstruction. We found that the ischemic area of the IV segment decreased significantly after IV segment portal vein reconstruction. We found that there was no significant difference in operation time and postoperative complications between the patients of the groups. There were significant differences in ALT on the 1st day and albumin on the 6th day after the operation.

Conclusion

It indicates that IV segment reconstruction in SLT surgery can alleviate the graft ischemic and promote the recovery of liver function after the operation. And, IV segment reconstruction as a novel operating procedure may be widely used in SLT.

"Beyond MELD" - Emerging strategies and technologies for improving mortality prediction, organ allocation and outcomes in liver transplantation

In this review article, we discuss the model for end-stage liver disease (MELD) score and its dual purpose in general and transplant hepatology. As the landscape of liver disease and transplantation has evolved considerably since the advent of the MELD score, we summarise emerging concepts, methodologies, and technologies that may improve mortality prognostication in the future. Finally, we explore how these novel concepts and technologies may be incorporated into clinical practice.

Living Donor Liver Transplantation vs. Split Liver Transplantation Using Left Lateral Segment Grafts in Pediatric Recipients: An Analysis of the UNOS Database

Split and LDLT in pediatric patients have the potential to decrease wait times and waitlist mortality. Using UNOS-STAR data, we compared outcomes of pediatric patients undergoing LDLT and SLT using LLS grafts. The baseline characteristics and post-operative outcomes were compared between groups. Actuarial graft and patient survival were analyzed with Kaplan-Meier curves. Between 2010 and 2019, 911 pediatric LT were included in the analysis (LD graft group, n = 508, split graft group, n = 403). LD graft recipients spent more time on the waitlist vs. the split graft group (60 (22–138) days vs. 46 (16–108) days; p = 0.007). LD recipients had a lower rate of graft failure, found in 9.8% of patients compared with 14.6% in the split graft group (p = 0.02). HAT was the most common graft failure cause, with similar rates. Graft and patient survival at 1-, 3-, and 5-years was comparable between LDLT and SLT. In subgroup analyses, patients with biliary atresia, those ≤10 kg or ≤10 years old receiving an LD graft showed improved graft survival. In conclusion, LDLT is associated with a lower rate of graft failure in pediatric patients. The use of LLS regardless of the type of donor is a safe way to facilitate access to transplantation to pediatric patients with acceptable short and long-term outcomes.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

Split liver transplantation (SLT) is 1 strategy for maximizing the number of deceased donor liver transplants. Recent reports suggest that utilization of SLT in the United States remains low. We examined deceased donor offers that were ultimately split between 2010 and 2014. SLTs were categorized as "primary" and "secondary" transplants. We analyzed allocation patterns and used logistic regression to evaluate factors associated with secondary split discard. Four hundred eighteen livers were split: 54% from adult, 46% from pediatric donors. Of the 227 adult donor livers split, 61% met United Network for Organ Sharing "optimal" split criteria. A total of 770 recipients (418 primary and 352 secondary) were transplanted, indicating 16% discard. Ninety-two percent of the 418 primary recipients were children, and 47% were accepted on the first offer. Eighty-seven percent of the 352 secondary recipients were adults, and 7% were accepted on the first offer. Of the 352 pairs, 99% were transplanted in the same region, 36% at the same center. In logistic regression, shorter donor height was associated with secondary discard (odds ratio 0.97 per cm, 95% CI 0.94-1.00, P = .02). SLT volume by center was not predictive of secondary discard. Current policy proposals that incentivize SLT in the United States could increase the number of transplants to children and adults.

Frequency of whole-organ in lieu of split-liver transplantation over the last decade: Children experienced increased wait time and death

Organ shortage is a barrier to liver transplantation (LT). Split LT (SLT) increases organ utilization, saving 2 recipients. A simulation of Organ Procurement and Transplantation Network/United Network for Organ Sharing data (2007-2017) was performed to identify whole-organ LT grafts (WLT) that met the criteria for being splittable to 2 recipients. Waitlist consequences presented. Deceased donor (DD) livers transplanted as whole organs were evaluated for suitability to split. Of these DD organs, we identified the adolescent and adult recipients of WLT who were suitable for SLT. Pediatric candidates suitable to share the SLT were ascertained from DD match-run lists, and 1342 splittable DD organs were identified; 438 WLT recipients met the criteria for accepting a SLT. Review of the 438 DD match-run lists identified 420 children next on the list suitable for SLT. Three hundred thirty-three children (79%) underwent LT, but had longer wait-times compared to 591 actual pediatric SLT recipients (median 147 days vs 44 days, P  < 0.001). Thirty-three of 420 children died on waitlist after a mean 206 days (standard deviation 317). Sharing organs suitable for splitting increases the number of LT, saving more lives. With careful patient selection, SLT will not be a disadvantage to the adult recipients. With a children-first allocation scheme, SLT will naturally increase the number of allografts because adult organs are too large for small children.

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.

Elevated Risk of Split-Liver grafts in adult liver Transplantation: Statistical Artifact or Nature of the Beast?

A recent study using US national registry data reported, using Cox proportional hazards (PH) models, that split-liver transplantation (SLT) has improved over time and is no more hazardous than whole-liver transplantation (WLT). However, the study methods violated the PH assumption, which is the fundamental assumption of Cox modeling. As a result, the reported hazard ratios (HRs) are biased and unreliable. This study aimed to investigate whether the risk of graft survival (GS) in SLT has really improved over time, ensuring attention to the PH assumption. This study included 80,998 adult deceased donor liver transplantation (LT) (1998-2015) from the Scientific Registry Transplant Recipient. The study period was divided into 3 time periods: era 1 (January 1998 to February 2002), era 2 (March 2002 to December 2008), and era 3 (January 2009 to December 2015). The PH assumption was tested using Schoenfeld's test, and where the HR of SLT violated the assumption, changes in risk for SLT over time from transplant were assessed. SLT was performed in 1098 (1.4%) patients, whereas WLT was used in 79,900 patients. In the Cox PH analysis, the P values of Schoenfeld's global tests were <0.05 in all eras, which is consistent with deviation from proportionality. Assessing HRs of SLT with a time-varying effect, multiple Cox models were conducted for post-LT intervals. The HR curves plotted according to time from transplant were higher in the early period and then decreased at approximately 1 year and continued to decrease in all eras. For 1-year GS, the HRs of SLT were 1.92 in era 1, 1.52 in era 2, and 1.47 in era 3 (all P < 0.05). In conclusion, the risk of SLT has a time-varying effect and is highest in the early post-LT period. The risk of SLT is underestimated if it is evaluated by overall GS. SLT was still hazardous if the PH assumption was considered, although it became safer over time.

Living or deceased organ donors in liver transplantation for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

The outcomes of living donor liver transplantation (LDLT) versus deceased donor liver transplantation (DDLT) for HCC patients were not well defined and it was necessary to reassess.

METHODS

A comprehensive literature search was conducted in PubMed, Embase, Cochrane Library, Google Scholar and WanFang database for eligible studies. Perioperative and survival outcomes of HCC patients underwent LDLT were pooled and compared to those underwent DDLT.

RESULTS

Twenty-nine studies with 5376 HCC patients were included. For HCC patients underwent LDLT and DDLT, there were comparable rates of overall survival (OS) (1-year, RR = 1.04, 95%CI = 1.00-1.09, P = 0.03; 3-year, RR = 1.03, 95%CI = 0.96-1.11, P = 0.39; 5-year, RR = 1.04, 95%CI = 0.95-1.13, P = 0.43), disease free survival (DFS) (1-year, RR = 1.00, 95%CI = 0.95-1.05, P = 0.99; 3-year, RR = 1.00, 95%CI = 0.94-1.08, P = 0.89; 5-year, RR = 1.01, 95%CI = 0.93-1.09, P = 0.85), recurrence (1-year, RR = 1.41, 95%CI = 0.72-2.77, P = 0.32; 3-year, RR = 0.89, 95%CI = 0.57-1.39, P = 0.60; and 5-year, RR = 0.85, 95%CI = 0.56-1.31, P = 0.47), perioperative mortality within 3 months (RR = 0.89, 95%CI = 0.50-1.59, p = 0.70) and postoperative complication (RR = 0.99, 95%CI = 0.70-1.39, P = 0.94). LDLT was associated with better 5-year intention-to-treat patient survival (ITT-OS) than DDLT (RR = 1.11, 95% CI = 1.01-1.22, P = 0.04).

CONCLUSION

This meta-analysis suggested that LDLT was not inferior to DDLT in consideration of comparable perioperative and survival outcomes. However, in terms of 5-year ITT-OS, LDLT was a possibly better choice for HCC patients.

Expansion of the Liver Donor Supply Through Greater Use of Split-Liver Transplantation: Identifying Optimal Recipients

The increased use of split-liver transplantation (SLT) represents a strategy to increase the supply of organs. Although outcomes after SLT and whole liver transplantation (WLT) are similar on average among pediatric recipients, we hypothesized that the relationship between graft type and outcomes may vary depending on patient, donor, and surgical characteristics. We evaluated graft survival among pediatric (<18 years) deceased donor, liver-only transplant recipients from March 2002 until December 2015 using data from the Scientific Registry of Transplant Recipients. Graft survival was assessed in a Cox proportional hazards model, with and without effect modification between graft type and donor, recipient, and surgical characteristics, to identify conditions where the risk of graft loss for SLT and WLT were similar. In a traditional multivariable model, characteristics associated with graft loss included donor age >50 years, recipient weight <10 kg, acute hepatic necrosis, autoimmune diseases, tumor, public insurance, and cold ischemia time (CIT) >8 hours. In an analysis that explored whether these characteristics modified the relationship between graft type and graft loss, many characteristics associated with loss actually had similar outcomes regardless of graft type, including weight <10 kg, acute hepatic necrosis, autoimmune diseases, and tumor. In contrast, several subgroups had worse outcomes when SLT was used, including recipient weight 10-35 kg, non-biliary atresia cholestasis, and metabolic disease. Allocation score, share type, or CIT did not modify risk of graft type and graft failure. Although one might anticipate that individuals with higher rates of graft loss would be worse candidates for SLT, data suggest that these patients actually have similar rates of graft loss. These findings can guide surgical decision making and may support policy changes that promote the increased use of SLT for specific pediatric recipients.

Split liver transplantation: Current developments

In 1988, Rudolf Pichlmayr pioneered split liver transplantation (SLT), enabling the transplantation of one donor liver into two recipients - one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.

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.

Survival Outcomes in Split Compared With Whole Liver Transplantation

Split-liver transplantation (SLT) should be cautiously considered because the right trisection (RTS) graft can be a marginal graft in adult recipients. Herein, we analyzed the outcomes of RTS-SLT in Korea, where >75% of adult liver transplantations are performed with living donor liver transplantation. Among 2462 patients who underwent deceased donor liver transplantations (DDLTs) from 2005 to 2014, we retrospectively reviewed 86 (3.5%) adult patients who received a RTS graft (RTS-SLT group). The outcomes of the RTS-SLT group were compared with those of 303 recipients of whole liver (WL; WL-DDLT group). Recipient age, laboratory Model for End-Stage-Liver Disease (L-MELD) score, ischemia time, and donor-to-recipient weight ratio (DRWR) were not different between the 2 groups (P > 0.05). However, malignancy was uncommon (4.7% versus 36.3%), and the donor was younger (25.2 versus 42.7 years) in the RST-SLT group than in the WL-DDLT group (P < 0.05). The technical complication rates and the 5-year graft survival rates (89.0% versus 92.8%) were not different between the 2 groups (P > 0.05). The 5-year overall survival (OS) rate (63.1%) and graft-failure-free survival rate (63.1%) of the RTS-SLT group were worse than that of the WL-DDLT group (79.3% and 79.3%; P < 0.05). The factors affecting graft survival rates were not definite. However, the factors affecting OS in the RTS-SLT group were L-MELD score >30 and DRWR ≤1.0. In the subgroup analysis, OS was not different between the 2 groups if the DRWR was >1.0, regardless of the L-MELD score (P > 0.05). In conclusion, a sufficient volume of the graft estimated from DRWR-matching could lead to better outcomes of adult SLTs with a RTS graft, even in patients with high L-MELD scores.

Fifteen-Year Trends in Pediatric Liver Transplants: Split, Whole Deceased, and Living Donor Grafts

OBJECTIVE

To evaluate changes in patient and graft survival for pediatric liver transplant recipients since 2002, and to determine if these outcomes vary by graft type (whole liver transplant, split liver transplant [SLT], and living donor liver transplant [LDLT]).

STUDY DESIGN

We evaluated patient and graft survival among pediatric liver-only transplant recipients the PELD/MELD system was implemented using the Scientific Registry of Transplant Recipients.

RESULTS

From 2002-2009 to 2010-2015, survival for SLT at 30 days improved (94% vs 98%; P < .001), and at 1 year improved for SLT (89% to 95%; P <.001) and LDLT (93% to 98%; P = .002). There was no change in survival for whole liver transplant at either 30 days (98% in both; P = .7) or 1 year (94% vs 95%; P = .2). The risk of early death with SLT was 2.14-fold higher in 2002-2009 (adjusted hazard ratio [aHR] vs whole liver transplant, 1.472.143.12), but this risk disappeared in 2010-2015 (aHR, 0.651.131.96), representing a significant improvement (P = .04). Risk of late death after SLT was similar in both time periods (aHR 2002-2009, 0.871.141.48; aHR 2010-2015, 0.560.881.37). LDLT had similar risk of early death (aHR 2002-2009, 0.491.032.14; aHR 2010-2015, 0.260.742.10) and late death (aHR 2002-2009, 0.520.831.32; aHR 2010-2015, 0.170.441.11). Graft loss was similar for SLT (aHR, 0.931.091.28) and was actually lower for LDLT (aHR, 0.530.710.95).

CONCLUSIONS

In recent years, outcomes after the use of technical variant grafts are comparable with whole grafts, and may be superior for LDLT. Greater use of technical variant grafts might provide an opportunity to increase organ supply without compromising post-transplant outcomes.

Fighting Mortality in the Waiting List: Liver Transplantation in North America, Europe, and Asia

Liver disease is a major cause of mortality worldwide. Liver transplantation (LT) is the most effective treatment for end stage liver disease. Available resources and social circumstances have led to different ways of implementing LT around the world. The experience with pediatric LT corroborates the hypothesis that a combination of surgical strategies can be beneficial. The goal of this manuscript is to describe the strategies used by LT centers in North America, Europe and Asia and how these strategies can be applied to reduce waitlist mortality and increase access to LT.

Outcomes of left split graft transplantation in Europe: report from the European Liver Transplant Registry

Split liver transplantation (SLT) has been widely adopted across Europe, resulting in remarkable reduction in the paediatric waiting-list mortality. Left split graft (LSG) is commonly used for paediatric recipients; however, deceased donor criteria selection are not universal. The aim of this study was to analyse the LSG outcome from the European Liver Transplant Registry and to identify risk factors for graft failure. Data from 1500 children transplanted in 2006-2014 with LSG from deceased donors were retrospectively analysed. Overall, graft losses were 343(22.9%) after 5 years from transplantation, 240(70.0%) occurred within the first 3 months. Estimated patient survival was 89.1% at 3 months and 82.9% at 5 years from SLT. Re-transplantation rate was 11.5%. At multivariable analysis, significant risk factors for graft failure at 3 months included the following: urgent SLT (HR = 1.73, P = 0.0012), recipient body weight ≤6 kg (HR = 1.91, P = 0.0029), donor age >50 years (HR = 1.87, P = 0.0039), and cold ischaemic time (CIT) [HR = 1.07 per hour, P = 0.0227]. LSG has good outcomes and SLT is excellent option for paediatric recipients in the current organ shortage era. We identified practical guidelines for LSG donor and recipient selection criteria: donor age may be safely extended up to 50 years in the absence of additional risk factors; thus, children <6 kg and urgent transplantation need CIT <6 h and appropriate graft/recipient size-matching to achieve good 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.

A matched pair analysis of multicenter longterm follow-up after split-liver transplantation with extended right grafts

Split-liver transplantation has been proposed as an alternative to whole liver (WL) transplantation to expand the donor pool, but studies comparing adult longterm outcomes between the 2 methods are conflicting and limited. This is the first Italian multicenter study that retrospectively analyzed 119 matched-pair recipients of whole and extended right grafts (ERGs) for longterm survival outcomes. In the overall population, WL recipients showed higher patient survival at 1 (93% versus 73%), 5 (87% versus 65%), and 10 years (83% versus 60%) after transplantation compared with split-liver recipients (P < 0.001); graft survivals of WL recipients were also superior at 1 (90% versus 76%), 5 (84% versus 57%), and 10 years (81% versus 52%) posttransplant (P < 0.001). However, among the 81 matched pairs that survived the first posttransplant year, 5- and 10-year patient survivals were 90% and 81% for split recipients and 99% and 96% for whole recipients, respectively (P = 0.34). The 5- and 10-year graft survivals were also comparable: 87% and 77% for split recipients, and 86% and 82% for whole recipients (P = 0.86). Cox regression analysis identified donor age >50, donor-to-recipient weight ratio < 1, retransplantation status, and United Network for Organ Sharing I-IIA status as risk factors for partial graft use. There were no significant differences in 5-year outcomes based on center volume. In conclusion, we demonstrate that adult liver transplantation with ERGs can achieve longterm success comparable with that of whole grafts in appropriate patients but should be selectively used in patients with risk factors. Liver Transplantation 23 1384-1395 2017 AASLD.

Effects of recipient size and allograft type on pediatric liver transplantation for biliary atresia

The majority of pediatric patients with end-stage liver disease receive a transplant with a whole liver (WL) allograft. However, smaller recipients with biliary atresia (BA) may have improved outcomes with deceased donor partial liver (DDPL) or living donor allografts. This study compares the national outcomes for liver transplantation in BA, with attention to the interaction between liver allograft type and recipient size. From January 2, 2002 to December 30, 2014, 2123 pediatric patients underwent a primary liver transplant for BA. The majority of transplants (53%) were performed with a WL allograft. Utilization of a WL allograft increased from 42% of recipients weighing ≤ 7 kg to 74% of recipients weighing > 14 kg. The 1-, 5-, and 10-year graft survival in recipients weighing ≤7 kg was significantly superior for living donor liver transplantation (LDLT) (91%, 88%, 84%) and DDPL allografts (90%, 84%, 77%) compared with WL allografts (79%, 75%, 74%; P = 0.005). The 1-, 5-, and 10-year graft survival in recipients weighing >14 kg trended toward being inferior in recipients of DDPL allografts (85%, 85%, 71%) compared with WL allografts (96%, 91%, 86%; P = 0.06). Furthermore, the incidence of vascular thrombosis was highest in WL (13%) compared with LDLT (6%) and DDPL (5%) recipients ≤ 7 kg (P = 0.002). Liver retransplantation was also highest in WL (16%) compared with LDLT (9%) and DDPL (9%) recipients ≤ 7 kg (P = 0.02). In conclusion, strong consideration should be given to the use of technical variant allografts in small recipients with BA requiring liver transplantation. Liver Transplantation 23 221-233 2017 AASLD.

Global lessons in graft type and pediatric liver allocation: A path toward improving outcomes and eliminating wait-list mortality

Current literature and policy in pediatric liver allocation and organ procurement are reviewed here in narrative fashion, highlighting historical context, ethical framework, technical/procurement considerations, and support for a logical way forward to an equitable pediatric liver allocation system that will improve pediatric wait-list and posttransplant outcomes without adversely affecting adults. Where available, varying examples of successful international pediatric liver allocation and split-liver policy will be compared to current US policy to highlight potential strategies that can be considered globally. Liver Transplantation 23:86-95 2017 AASLD.

Biliary atresia: Indications and timing of liver transplantation and optimization of pretransplant care

Biliary atresia (BA) is a progressive, fibro-obliterative disorder of the intrahepatic and extrahepatic bile ducts in infancy. The majority of affected children will eventually develop end-stage liver disease and require liver transplantation (LT). Indications for LT in BA include failed Kasai portoenterostomy, significant and recalcitrant malnutrition, recurrent cholangitis, and the progressive manifestations of portal hypertension. Extrahepatic complications of this disease, such as hepatopulmonary syndrome and portopulmonary hypertension, are also indications for LT. Optimal pretransplant management of these potentially life-threatening complications and maximizing nutrition and growth require the expertise of a multidisciplinary team with experience caring for BA. The timing of transplant for BA requires careful consideration of the potential risk of transplant versus the survival benefit at any given stage of disease. Children with BA often experience long wait times for transplant unless exception points are granted to reflect severity of disease. Family preparedness for this arduous process is therefore critical. Liver Transplantation 23:96-109 2017 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.

Efficacy of recombinant thrombomodulin for DIC after deceased donor liver transplantation: a case report

BACKGROUND

Disseminated intravascular coagulation (DIC) after liver transplantation (LT) is a difficult complication. We report a case of disseminated intravascular coagulation after deceased donor liver transplantation (DDLT) treated with recombinant thrombomodulin (rTM).

CASE PRESENTATION

A 30-year-old woman underwent right tri-segment split graft DDLT for acute liver failure. She developed disseminated intravascular coagulation on post-operative day 5 with fever. Computed tomography revealed necrosis of hepatic segment IV, and her acute-phase disseminated intravascular coagulation score was seven points. She was given rTM, and the inflammation, liver function, and coagulation disorders immediately improved. However, pleural effusion drainage from the chest tube became bloody on post-operative day 11, and rTM was discontinued. She progressed well and was discharged from the hospital on post-operative day 28. rTM is an effective treatment for disseminated intravascular coagulation; however, rTM for cases with coagulation disorders, which can occur after liver transplantation, has both risks and benefits.

CONCLUSIONS

We report a case of DIC after LT, in which rTM was potentially effective. Further studies are needed to determine the appropriate dosages, duration, and additional considerations for rTM therapy in liver transplantation patients.

Extended-criteria donors in liver transplantation Part II: reviewing the impact of extended-criteria donors on the complications and outcomes of liver transplantation

Extended-criteria donors (ECDs) have an impact on early allograft dysfunction (EAD), biliary complications, relapse of hepatitis C virus (HCV), and survivals. Early allograft dysfunction was frequently seen in grafts with moderate and severe steatosis. Donors after cardiac death (DCD) have been associated with higher rates of graft failure and biliary complications compared to donors after brain death. Extended warm ischemia, reperfusion injury and endothelial activation trigger a cascade, leading to microvascular thrombosis, resulting in biliary necrosis, cholangitis, and graft failure. The risk of HCV recurrence increased by donor age, and associated with using moderately and severely steatotic grafts. With the administration of protease inhibitors sustained virological response was achieved in majority of the patients. Donor risk index and EC donor scores (DS) are reported to be useful, to assess the outcome. The 1-year survival rates were 87% and 40% respectively, for donors with a DS of 0 and 3. Graft survival was excellent up to a DS of 2, however a DS >2 should be avoided in higher-risk recipients. The 1, 3 and 5-year survival of DCD recipients was comparable to optimal donors. However ECDs had minor survival means of 85%, 78.6%, and 72.3%. The graft survival of split liver transplantation (SLT) was comparable to that of whole liver orthotopic liver transplantation. SLT was not regarded as an ECD factor in the MELD era any more. Full-right-full-left split liver transplantation has a significant advantage to extend the high quality donor pool. Hypothermic oxygenated machine perfusion can be applied clinically in DCD liver grafts. Feasibility and safety were confirmed. Reperfusion injury was also rare in machine perfused DCD livers.

Split liver transplantation: Report of right and left graft outcomes from a multicenter Argentinean group

Grafts from split livers (SLs) constitute an accepted approach to expand the donor pool. Over the last 5 years, most Argentinean centers have shown significant interest in increasing the use of this technique. The purpose of this article is to describe and analyze the outcomes of right-side grafts (RSGs) and left-side grafts (LSGs) from a multicenter study. The multicenter retrospective study included data from 111 recipients of SL grafts from between January 1, 2009 and December 31, 2013. Incidence of surgical complications, patient and graft survival, and factors that affected RSG and LSG survival were analyzed. Grafts types were 57 LSG and 54 RSG. Median follow-up times for LSG and RSG were 46 and 42 months, respectively. The 36-month patient and graft survivals for LSG were 83% and 79%, respectively, and for RSG were 78% and 69%, respectively. Retransplantation rates for LSG and RSG were 3.5% and 11%, respectively. Arterial complications were the most common cause of early retransplantation (less than 12 months). Cold ischemia time (CIT) longer than 10 hours and the use of high-risk donors (age ≥ 40 years or body mass index ≥ 30 kg/m2 or ≥ 5 days intensive care unit stay) were independent factors for diminished graft survival in RSG. None of the analyzed variables were associated with worse graft survival in LSG. Biliary complications were the most frequent complications in both groups (57% in LSG and 33% in RSG). Partial grafts obtained from liver splitting are an excellent option for patients in need of liver transplantation and have the potential to alleviate the organ shortage. Adequate donor selection and reducing CIT are crucial for optimizing results.

Outcomes of Full-Right-Full-Left Split Liver Transplantation in Adults in the USA: A Propensity-Score Matched Analysis

BACKGROUND

Splitting a liver for utilization in adult/pediatric recipients has been shown to decrease mortality on the wait list without increasing the overall risk of long-term graft failure compared to a whole graft. However, splitting a single donor organ for two adult recipients, full-right-full-left split liver transplantation (FRFLSLT), to overcome organ shortage is still considered controversial.

OBJECTIVE

This study assessed the outcome of FRFLSLT comparing full-right (FR) and full-left (FL) with whole liver (WL) allografts in adults (1998-2010) using UNOS standard transplant analysis and research (STAR) file. Methods: Unadjusted allograft and patient survival were estimated using Kaplan-Meier survival curves. Adjusted analyses of survival were conducted controlling for propensity for WL allograft.

RESULTS

There were 83,313 cases of WL, 651 FR and 117 FL. Significant differences were evident in the unadjusted cohort between recipients who received FR and FL including donor, cold ischemic time, and days on transplant waiting list. Use of FL allograft resulted in a trend toward lower graft and patient survival compared to WL and FR, which was not statistically significant (p=0.07). In the matched cohort, FL hemiliver allograft had no detrimental effect on the allograft or patient survival after split liver transplantation when compared to FR and WL.

CONCLUSION

After adjusting for donor and recipient characteristics, there was no difference in allograft or patient survival with the use of FL, FR, or WL after liver transplantation in adults. FRFLSLT is a valuable and safe option to expand the donor pool.

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.

Split liver transplantation: What’s unique?

The intraoperative management of split liver transplantation (SLT) has some unique features as compared to routine whole liver transplantations. Only the liver has this special ability to regenerate that confers benefits in survival and quality of life for two instead of one by splitting livers. Primary graft dysfunction may result from small for size syndrome. Graft weight to recipient body weight ratio is significant for both trisegmental and hemiliver grafts. Intraoperative surgical techniques aim to reduce portal hyperperfusion and decrease venous portal pressure. Ischemic preconditioning can be instituted to protect against ischemic reperfusion injury which impacts graft regeneration. Advancement of the technique of SLT is essential as use of split cadaveric grafts expands the donor pool and potentially has an excellent future.

Split liver transplantation: Papering over the cracks of the organ shortage

Splitting livers allows two people (usually an adult and a child) to receive a liver transplant from one donated adult liver, but the risks to the adult recipient are greater than if they had received the equivalent whole liver. It has been suggested, therefore, that splitting livers harms adult recipients. Without liver splitting, however, there would be few livers available for children, and paediatric waiting time and waiting list mortality would significantly increase. In this paper, we argue that although splitting livers makes adults worse off, this should be considered sub-optimal benefit rather than harm. We explore justifications for sub-optimally benefitting adults in this way and consider alternatives to the current approach. We argue that splitting livers masks the more fundamental problem of low paediatric donation rates and that increasing the number of paediatric donations would improve the situation for both adult and paediatric liver patients.

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.

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.

Liver transplantation for the referring physician

Liver transplantation has become the treatment of choice for nearly all causes of end-stage liver disease, fulminant liver failure, and selected primary hepatic malignancies. The demand for liver transplantation has persistently outmatched the availability of donor organs leading to the development of novel strategies to expand the donor pool. The authors review the process of liver transplant evaluation, methods used to address the donor shortage, and disease-specific outcomes and challenges and discuss posttransplant care.

Vasculobiliary complications following adult right lobe split liver transplantation from the perspective of reconstruction techniques

Split liver transplantation (SLT) compensates for the organ shortage and provides an alternative solution for recipients disadvantaged by a smaller body size. Variations in the hepatic arterial anatomy and reconstructive techniques may lead to more technical complications, and we sought to analyze the incidence and risk factors of vasculobiliary complications with respect to reconstructive techniques. We identified 171 adult right lobe SLT procedures and 1412 whole liver transplantation (WLT) procedures between January 2000 and June 2012 and compared the results of these 2 groups. In the SLT group, arterial reconstruction techniques were classified into 4 subgroups (I-IV), and biliary reconstruction was classified into 2 groups [duct-to-duct (DD) anastomosis and Roux-en-Y hepaticojejunostomy (RH)]. Specific surgical complications were analyzed against reconstruction techniques. The overall incidence of vascular and biliary complications in the SLT group was greater than that in the WLT group (P = 0.009 and P = 0.001, respectively). There was no difference in hepatic artery thrombosis (HAT), but we saw a tendency toward early HAT in the presence of multiple hepatic arteries supplying the right lobe graft (group IV; 20%) in comparison with the other arterial reconstruction groups (P = 0.052). No difference was noticed in the overall incidence of biliary complications in either DD or RH recipients across 4 arterial reconstruction groups. When the arterial reconstruction involved a right hepatic artery (groups II and III) combined with a DD biliary anastomosis, there was a significant preponderance of biliary complications (P = 0.04 and P = 0.01, respectively). There was no survival difference between SLT and WLT grafts. In conclusion, the complications of SLT are directly related to arterial and biliary reconstruction techniques, and this classification helps to identify high-risk reconstructive techniques.

Beyond the Pediatric end-stage liver disease system: Solutions for infants with biliary atresia requiring liver transplant

Biliary atresia (BA), a chronic progressive cholestatic disease of infants, is the leading cause for liver transplant in children, especially in patients under two years of age. BA can be successfully treated with the Kasai portoenterostomy; however most patients still require a liver transplant, with up to one half of BA children needing a transplant by age two. In the current pediatric end-stage liver disease system, children with BA face the risk of not receiving a liver in a safe and timely manner. In this review, we discuss a number of possible solutions to help these children. We focus on two general approaches: (1) preventing/delaying need for transplantation, by optimizing the success of the Kasai operation; and (2) expediting transplantation when needed, by performing techniques other than the standard deceased-donor, whole, ABO-matched organ transplant.

Advances in the management of the explanted donor liver

Liver transplantation is the best therapy in end-stage liver disease. Donor organ shortage and efforts to expand the donor organ pool are permanent issues given that advances in perioperative management and immunosuppressive therapy have brought the procedure into widespread clinical use. The management of organ procurement, including donor preconditioning and adequate organ storage, has a key role in transplantation. However, the organ procurement process can differ substantially between transplant centres, depending on local and national preferences. Advances in the field have come from experimental and clinical research on dynamic storage systems, such as machine perfusion devices, as an alternative to static cold storage. Determination of the clinical significance of these new systems is a topic worthy of future investigations.