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

How to apply ex-vivo split liver transplantation safely and feasibly: A three-step approach

BACKGROUND

Given the current organ shortage crisis, split liver transplantation (SLT) has emerged as a promising alternative for select end-stage liver disease patients.

AIM

To introduce an ex-vivo liver graft splitting approach and evaluate its safety and feasibility in SLT.

METHODS

A retrospective analysis was conducted on the liver transplantation data from cases performed at our center between April 1, 2022, and May 31, 2023. The study included 25 SLT cases and 81 whole liver transplantation (WLT) cases. Total ex-vivo liver splitting was employed for SLT graft procurement in three steps. Patient outcomes were determined, including liver function parameters, postoperative complications, and perioperative mortality. Group comparisons for categorical variables were performed using the χ²-test.

RESULTS

In the study, postoperative complications in the 25 SLT cases included hepatic artery thrombosis (n = 1) and pulmonary infections (n = 3), with no perioperative mortality. In contrast, among the 81 patients who underwent WLT, complications included perioperative mortality (n = 1), postoperative pulmonary infections (n = 8), abdominal infection (n = 1), hepatic artery thromboses (n = 3), portal vein thrombosis (n = 1), and intra-abdominal bleeding (n = 5). Comparative analysis demonstrated significant differences in alanine aminotransferase (176.0 vs 73.5, P = 0.000) and aspartate aminotransferase (AST) (42.0 vs 29.0, P = 0.004) at 1 wk postoperatively, and in total bilirubin (11.8 vs 20.8, P = 0.003) and AST (41.5 vs 26.0, P = 0.014) at 2 wk postoperatively. However, the overall incidence of complications was comparable between the two groups (P > 0.05).

CONCLUSION

Our findings suggest that the total ex-vivo liver graft splitting technique is a safe and feasible approach, especially under the expertise of an experienced transplant center. The approach developed by our center can serve as a valuable reference for other transplantation centers.

The adverse impact of perioperative body composition abnormalities on outcomes after split liver transplantation: a multicenter retrospective cohort study

BACKGROUND

Split liver transplantation (SLT) increases graft availability, but it's safe and effective utilization is insufficiently documented. This study aimed to investigate the association between perioperative body composition abnormalities and outcomes in adult SLT.

MATERIALS AND METHODS

Two hundred forty recipients who underwent SLT in three centers were enrolled in this retrospective cohort study. Body composition abnormalities including sarcopenia, myosteatosis, visceral obesity, and sarcopenic obesity were evaluated at baseline and 1 month after surgery using computed tomography. Their impact on outcomes including early allograft dysfunction, early complications, ICU stay, graft regeneration rate, and survival was analyzed.

RESULTS

Recipients with sarcopenia or myosteatosis had a higher risk of early allograft dysfunction, higher early complication rate, and longer length of ICU stay (all P <0.05), while there was no difference in graft regeneration rate. Recipient and graft survival were significantly worse for recipients with body composition abnormalities (all P <0.05). In multivariable Cox-regression analysis, sarcopenia [hazard ratio (HR)=1.765, P =0.015], myosteatosis (HR=2.066, P =0.002), and visceral obesity (HR=1.863, P =0.008) were independently associated with shorter overall survival. Piling up of the three factors increased the mortality risk stepwise ( P <0.001). Recipients experienced skeletal muscle loss and muscle fat infiltration 1 month after surgery. Postoperative worsening sarcopenia (HR=2.359, P =0.009) and myosteatosis (HR=1.878, P =0.026) were also identified as independent risk factors for mortality.

CONCLUSION

Sarcopenia, myosteatosis, and their progression negatively affect outcomes including early allograft dysfunction, early complications, ICU stay and survival after SLT. Systemic evaluation and dynamic monitoring of body composition are valuable.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Biliary complications following split liver transplantation in adult recipients: a matched pair analysis on single-center experience

The utilization of split liver grafts can increase access to liver transplantation (LT) for adult patients, particularly when liver grafts are shared between 2 adult recipients. However, it is yet to be determined whether split liver transplantation (SLT) increases the risk of biliary complications (BCs) compared with whole liver transplantation (WLT) in adult recipients. This retrospective study enrolled 1441 adult patients who underwent deceased donor LT at a single-site between January 2004 and June 2018. Of those, 73 patients underwent SLTs. Graft type for SLT includes 27 right trisegment grafts, 16 left lobes, and 30 right lobes. A propensity score matching analysis selected 97 WLTs and 60 SLTs. Biliary leakage was more frequently seen in SLTs (13.3% vs. 0%; p <0.001), whereas the frequency of biliary anastomotic stricture was comparable between SLTs and WLTs (11.7% vs. 9.3%; p=0.63). Graft and patient survival rates of patients undergoing SLTs were comparable to those undergoing WLTs (p=0.42 and 0.57, respectively). In the analysis of the entire SLT cohort, BCs were seen in 15 patients (20.5%) including biliary leakage in 11 patients (15.1%) and biliary anastomotic stricture in 8 patients (11.0%) [both in 4 patients (5.5%)]. The survival rates of recipients who developed BCs were significantly inferior to those without BCs (p <0.01). By multivariate analysis, the split grafts without common bile duct increased the risk of BCs. In conclusion, SLT increases the risk of biliary leakage compared with WLT. Biliary leakage can still lead to fatal infection and thus should be managed appropriately in SLT.

National Liver Allocation Policy-Consensus Document by the Liver Transplantation Society of India for a Nationally Uniform System of Allocation of Deceased Donor Liver Grafts

Background

Deceased donor liver transplantation (DDLT) is increasing in India and now constitutes nearly one-third of all liver transplantation procedures performed in the country. There is currently no uniform national system of allocation of deceased donor livers.

Methods

A national task force consisting of 19 clinicians involved in liver transplantation from across the country was constituted under the aegis of the Liver Transplantation Society of India to develop a consensus document addressing the above issues using a modified Delphi process of consensus development.

Results

The National Liver Allocation Policy consensus document includes 46 statements covering all aspects of DDLT, including minimum listing criteria, listing for acute liver failure, DDLT wait-list management, system of prioritisation based on clinical urgency for adults and children, guidelines for allocation of paediatric organs and allocation priorities for liver grafts recovered from public sector hospitals.

Conclusion

This document is the first step in the setting up of a nationally consistent policy of deceased donor liver allocation.

An appraisal of technical variant grafts compared to whole liver grafts in pediatric liver transplant recipients: Multicenter analysis from the SPLIT registry

BACKGROUND

Shortages of liver allografts for children awaiting transplantation have led to high LT waitlist mortality. Prior studies have shown that usage of TVG can reduce waiting time and waitlist mortality, but their use is not universal. We sought to compare patient and graft survival between WLG and TVG and to identify potential associated risk factors in a contemporary pediatric LT cohort.

METHODS

We performed a retrospective analysis of patient survival, graft survival, and biliary and vascular complications for LT recipients <18 years old entered into the Society of Pediatric Liver Transplantation prospective multicenter database.

RESULTS

Of 1839 LT recipients, 1029 received a WLG and 810 received a TVG from either a LD or a DD. There was no difference in patient survival or graft survival by graft type. Three-year patient survival and graft survival were 96%, 93%, and 96%, and 95%, 89%, and 92% for TVG-LD, TVG-DD, and WLG, respectively. Biliary complications were more frequent in TVG. Hepatic artery thrombosis was more frequent in WLG. Multivariate analysis revealed primary diagnosis was the only significant predictor of patient survival. Predictors for graft survival included time-dependent development of biliary and vascular complications.

CONCLUSIONS

There were no significant differences in patient and graft survival based on graft types in this North American multi-center pediatric cohort. Widespread routine use of TVG should be strongly encouraged to decrease mortality on the waitlist for pediatric LT candidates.

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.

Impact of allograft types on outcomes after pediatric liver transplantation due to biliary atresia

BACKGROUND

Several surgical strategies, including split donor transplantation and living donor transplantation, have been used to increase the donor liver pool. This report focuses on the effects of whole, split, and LDLT on recipient outcomes.

METHODS

We retrospectively analyzed the records of all patients with biliary atresia at Tianjin First Central Hospital between April 2013 and December 2019.

RESULTS

A total of 882 patients were included and divided into three groups by graft type, with 198 in the whole-liver-transplantation group, 78 in the split liver transplantation group, and 606 in the LDLT group. The median follow-up time was 39 months, patient survival rates of three groups were 94.4%, 88.5%, and 95.0%, respectively, and graft survival rates were 90.2%, 83.3%, and 94.7%, respectively. We divided the split liver transplantation group into two subgroups according to the donor's age, and patient survival rates exhibited a significant difference only in the group whose donor age was over 45 years. The postoperative complication rates were significantly higher with respect to hepatic artery thrombosis, portal stenosis, and AR; and lower in hepatic venous stenosis, PTLDs, CMV virus, and EBV infection in the WLT group. Our multivariate model showed that donor age ≥45 years, RBC transfusion, pneumonia, and HAT were the independent predictors of allograft loss.

CONCLUSIONS

The survival of split liver transplantation group was slightly lower. The types of complications are different from different graft types. Therefore, postoperative monitoring and treatment need to be adjusted according to the different graft types used.

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.

Liver transplantation for pediatric inherited metabolic liver diseases

Liver transplantation (LT) remains the gold standard treatment for end stage liver disease in the pediatric population. For liver based metabolic disorders (LBMDs), the decision for LT is predicated on a different set of paradigms. With improved outcomes post-transplantation, LT is no longer merely life saving, but has the potential to also significantly improve quality of life. This review summarizes the clinical presentation, medical treatment and indications for LT for some of the common LBMDs. We also provide a practical update on the dilemmas and controversies surrounding the indications for transplantation, surgical considerations and prognosis and long terms outcomes for pediatric LT in LBMDs. Important progress has been made in understanding these diseases in recent years and with that we outline some of the new therapies that have emerged.

Standard liver weight model in adult deceased donors with fatty liver: A prospective cohort study

BACKGROUND

Standard liver weight (SLW) is frequently used in deceased donor liver transplantation to avoid size mismatches with the recipient. However, some deceased donors (DDs) have fatty liver (FL). A few studies have reported that FL could impact liver size. To the best of our knowledge, there are no relevant SLW models for predicting liver size.

AIM

To demonstrate the relationship between FL and total liver weight (TLW) in detail and present a related SLW formula.

METHODS

We prospectively enrolled 212 adult DDs from West China Hospital of Sichuan University from June 2019 to February 2021, recorded their basic information, such as sex, age, body height (BH) and body weight (BW), and performed abdominal ultrasound (US) and pathological biopsy (PB). The chi-square test and kappa consistency score were used to assess the consistency in terms of FL diagnosed by US relative to PB. Simple linear regression analysis was used to explore the variables related to TLW. Multiple linear regression analysis was used to formulate SLW models, and the root mean standard error and interclass correlation coefficient were used to test the fitting efficiency and accuracy of the model, respectively. Furthermore, the optimal formula was compared with previous formulas.

RESULTS

Approximately 28.8% of DDs had FL. US had a high diagnostic ability (sensitivity and specificity were 86.2% and 92.9%, respectively; kappa value was 0.70, P < 0.001) for livers with more than a 5% fatty change. Simple linear regression analysis showed that sex (R2, 0.226; P < 0.001), BH (R2, 0.241; P < 0.001), BW (R2, 0.441; P < 0.001), BMI (R2, 0.224; P < 0.001), BSA (R2, 0.454; P < 0.001) and FL (R2, 0.130; P < 0.001) significantly impacted TLW. In addition, multiple linear regression analysis showed that there was no significant difference in liver weight between the DDs with no steatosis and those with steatosis within 5%. Furthermore, in the context of hepatic steatosis, TLW increased positively (non-linear); compared with the TLW of the non-FL group, the TLW of the groups with hepatic steatosis within 5%, between 5% and 20% and more than 20% increased by 0 g, 90 g, and 340 g, respectively. A novel formula, namely, -348.6 + (110.7 x Sex [0 = Female, 1 = Male]) + 958.0 x BSA + (179.8 x FLUS [0 = No, 1 = Yes]), where FL was diagnosed by US, was more convenient and accurate than any other formula for predicting SLW.

CONCLUSION

FL is positively correlated with TLW. The novel formula deduced using sex, BSA and FLUS is the optimal formula for predicting SLW in adult DDs.

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.

Outcomes of Pediatric Liver Transplantation in Japan: A Report from the Registry of the Japanese Liver Transplantation Society (JLTS)

BACKGROUND

The Japanese Liver Transplantation Society (JLTS), a cooperative research consortium, was established in 1980 in order to characterize and follow trends in patient characteristics and graft survival among all liver transplant patients in Japan. This study analyzed factors that may affect the current outcomes of pediatric patients who undergo LT by evaluating one of the largest pediatric LT cohorts in the world.

METHODS

Between November 1989 and December 2018, 3347 pediatric patients underwent LT in Japan. The survival outcomes of each donor and recipient variant were evaluated.

RESULTS

The procedures performed during the study period included living donor LT (LDLT; n=3271), deceased donor LT (DDLT; n=69), and domino LT (n=7). There were 1510 male (45.1%) and 1837 female (54.9%) recipients with a median age of 1.7 years (range: 9 days to17.9 years). The graft survival rates at 1, 10, 20, and 30 years were 88.9%, 82.2%, 77.1%, and 75.4%, respectively. Donor age, donor BMI, blood type incompatibility, recipient age, etiology of liver disease, transplant type, center experience, and transplant era were found to be significant predictors of overall graft survival. LDLT is a major treatment modality for end-stage liver disease in children; DDLT and domino LT were applied as alternative treatments for LDLT in patients with specific pediatric liver diseases that are considered to have a poor prognosis following LDLT.

CONCLUSIONS

Satisfactory long-term pediatric patient survival outcomes were achieved in the JLTS series, and we should continue to promote the deceased donor organ transplantation program in Japan.

HIV and Solid Organ Transplantation: Where Are we Now

PURPOSE OF REVIEW

We review the international evolution of HIV and solid organ transplantation over 30 years. We emphasise recent developments in solid organ transplantation from HIV-infected to HIV-uninfected individuals, and their implications.

RECENT FINDINGS

In 2017, Johannesburg, South Africa, a life-saving partial liver transplant from an HIV-infected mother to her HIV-uninfected child was performed. This procedure laid the foundation not only for consideration of HIV-infected individuals as living donors, but also for the possibility that HIV-uninfected individuals could receive organs from HIV-infected donors. Recent advances in this field are inclusion of HIV-infected individuals as living organ donors and the possibility of offering HIV-uninfected individuals organs from HIV-infected donors who are well-controlled on combination antiretroviral therapy (cART). The large number of HIV-infected individuals on cART is an unutilised source of otherwise eligible living organ donors. HIV-positive-to-HIV-negative organ transplantation has become a reality, providing possible new therapeutic options to address extreme organ shortages.